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[l] at 12/11/19 4:19am
by Andrew Glikson
Earth and climate scientist
Australian National University

Carbon, the essential element underpinning photosynthesis and life, is transformed into toxic substances in the remnants of plants and organisms buried in sediments. Once released to the atmosphere in the form of CO₂, CO and methane, in large quantities these gases become lethal and have been responsible for mass extinctions of species (Fig. 1).
Figure 1. Relations between CO₂ levels in the atmosphere and mass extinctions of genera.
Data cited from D. Royer et al. (2002), from G. Keller (2016) and P. Wignall et al. (2002). Figure 2. Potential heating, Carana (2019) Given amplifying feedbacks from land and oceans triggered by rising temperatures, the concept of an upper limit of warming determined by limitation on carbon emissions alone is unlikely, since, under a rising high greenhouse gas concentration, amplifying feedbacks triggered by methane release, bushfires, warming oceans and loss of reflectivity of melting ice, temperatures would keep rising. As an example, findings show that warmer ocean water is melting hydrates and releasing methane into the sediment and waters off the coast of Washington state, at levels that reach the same amount of methane from the Deepwater Horizon blowout. Carana (2019) finds a potential for abrupt warming of 18°C or 32.4°F (Fig. 2).

Attempts at CO₂ drawdown (sequestration), if urgently applied on a global scale, may conceivably be able to slow down further warming. This article refers to natural methane reservoirs and human-induced methane emissions, indicating that, once temperatures supersede a critical level, a further rise in methane release would result regardless of restrictions of emissions.

According to Kelley (2003) a planetary “runaway greenhouse event” may be triggered when a planet overheats due to absorption of more solar energy than it can give off to retain equilibrium. As a result, the oceans may boil filling its atmosphere with steam, which leaves the planet uninhabitable, as Venus is now. Planetary geologists think there is good evidence that Venus was the victim of a runaway greenhouse effect which turned the planet into the boiling hell we see today. According to Hansen (2010): “If we burn all fossil fuels, the forcing will be at least comparable to that of the PETM, but it will have been introduced at least ten times faster. [. .] The warming ocean can be expected to affect methane hydrate stability at a rate that could exceed that in the PETM, where the rate of change was driven by the speed of the methane hydrate climate feedback, not by the nearly instantaneous introduction of all fossil fuel carbon.” In a critical review of the theory of runaway greenhouse warming, Goldblatt and Watson (2012) state: “We cannot therefore completely rule out the possibility that human actions might cause a transition, if not to full runaway, then at least to a much warmer climate state than the present one.”

The concentration of fossil carbon deposits in the form of coal, oil, natural gas, coal seam gas, permafrost methane, ice clathrates, shale oil, and oil sands, once released to the atmosphere in large quantities, generates powerful feedbacks from land, ocean, atmosphere and cryosphere. This includes further release of greenhouse gases, warming oceans, loss of reflectivity of melting ice, and bushfires, pushing temperatures further upward. With carbon dioxide concentrations rising at a rate of 2–3 parts per million (ppm) per year (October 2018: 406.00 ppm; October 2019: 408.53 ppm) and the Earth heating-up by 0.98°C since 1951-1980, the ultimate consequences of this trend belong to the unthinkable.

Through 2012, total accumulated emissions are estimated to have reached 384 GtC, with an annual amount of 43.1 billion tonnes of carbon dioxide expected to be added in 2019.

A 2016 IPCC analysis found that no more than 275 GtC of the world’s reserves of fossil fuels of 746 GtC could be emitted, if the global temperature rise is to be restricted to 2°C above pre-industrial temperatures, an impossible target since amplifying carbon feedbacks would push temperatures upwards.

According to Heede and Oreskes (2016), global reserves of oil (~171 GtC), natural gas (~95) and coal (479 GtC) add up to a total of 746 GtC. Hansen et al. (2013) estimates that recoverable fossil fuel reserves include ~120 GtC gas, ~80 GtC oil, >10,000 GtC coal, >2000 GtC unconventional gas, and ~700 GtC unconventional oil, adding up to a total of ~13,000 GtC (Fig. 3).

Figure 4. Vulnerable carbon pools. (A) Land: Permafrost ~900 GtC; High-latitude peatlands ~400 GtC;
Tropical peatlands ~100 GtC; Vegetation subject to fire and/or deforestation ~650 GtC;
(B) Oceans: Methane hydrates ~10,000 GtC; Solubility pump ~2700 GtC; Biological pump ~3300 GtC;
Total (A) + (B): ~18,050 GtC (Canadell 2007 The amount of unstable methane deposits in permafrost and methane hydrates (clathrates) in ocean sediments is of a similar order of magnitude as the amount of fossil fuel reserves. Vulnerable carbon pools include methane hydrates in sediments (~10,000 GtC), solubility and biological pump (~6000 GtC), permafrost methane (~900 GtC), and peatlands and vulnerable vegetation (~1150 GtC), adding up to a total of ~18,050 GtC (Fig. 4).

Unoxidized metastable deposits of methane and methane hydrates, accumulated during the Pleistocene glacial-interglacial cycles and vulnerable to temperature rise, are already leaking as indicated by atmospheric concentrations which have risen from 1988 (~1700 ppb CH₄) to 2019 (~1860 ppb CH₄) at a rate of ~5.2 ppb/year, a rise of more than 4 ppm CO₂-equivalent at GWP25xCO₂ or 24 ppm CO₂-e at GWP150xCO₂.


Meinshausen et al. (2011) estimated global-mean surface temperature increases, applying a climate sensitivity of 3°C per doubling of CO₂, resulting by 2100 in a temperature rise of between 1.5°C to 4.5°C relative to pre-industrial levels. By 2300, under constant emissions, CO₂ concentrations would rise to ~2000 ppm, methane to 3.5 ppm and nitrous oxide to 0.52 ppm (Fig. 5). Amplifying feedbacks are taken into account, but the effects of tipping points and of cold ice-melt pools formed in the oceans near Greenland and Antarctica ice sheets are unclear.

Given the estimated total of exploitable hydrocarbon resources (~13.000 GtC) and of vulnerable carbon pools (~18,050 GtC), the amount released under different future climate conditions is subject to estimates:
  • Assuming mean global temperature of +2°C (above pre-industrial), with allowance made for the masking effects of sulphur aerosols, the combustion of ~2% of the fossil fuel reserves (13,000 GtC), i.e. ~260 GtC, would raise CO₂ concentration by ~130 ppm (100 GtC = 50 ppm CO₂) (Fig. 3). Combustion of ~5% of the fossil fuel reserve would raise CO₂ concentration by ~325 ppm. 
  • Under +2°C above pre-industrial, release of CO₂ from fires and other feedback effects such as melting of permafrost and release of methane would raise atmospheric carbon by at least 1 percent of vulnerable carbon pools (~18,050 GtC). 
  • The flow of ice melt water from Greenland and Antarctica into the oceans would create large regions of cold water capable of absorption of atmospheric CO₂. 
Hansen (2010) concludes: “if we burn all reserves of oil, gas, and coal, there's a substantial chance that we will initiate the runaway greenhouse. If we also burn the tar sands and tar shale, I believe the Venus syndrome [runaway greenhouse warming] is a dead certainty”Stephen Hawking (2017) appears to agree with Hansen’s warning, stating: “if the US pulls out of the Paris climate agreement it may lead to runaway global warming, eventually turning Earth's atmosphere into something resembling Venus”. Goldblatt and Watson (2012) wrote: “The ultimate climate emergency is a ‘runaway greenhouse’: a hot and water-vapor-rich atmosphere limits the emission of thermal radiation to space, causing runaway warming … This would evaporate the entire ocean and exterminate all planetary life … We cannot therefore completely rule out the possibility that human actions might cause a transition, if not to full runaway, then at least to a much warmer climate state than the present one … However, our understanding of the dynamics, thermodynamics, radiative transfer and cloud physics of hot and steamy atmospheres is weak.” 

An analysis by Carana (2013) suggests that accelerated release of methane from permafrost and methane hydrates (clathrates) could trigger runaway global warming (Fig. 6). A polynomial trend for the Arctic shows temperature anomalies of +4°C by 2020, +7°C by 2030 and +11°C by 2040, threatening major feedbacks, further albedo changes and methane releases leading to global temperature anomalies of 20°C+ by 2050.

Figure 6. A polynomial 2 trend line points at global temperature anomalies (Carana 2013). A polynomial function is a function such as a quadratic, a cubic, a quartic, and so on, involving only non-negative integer powers of x. The magnitude of the runaway greenhouse effect that now threatens to eventuate becomes evident when looking at the geological record. For example, the 55 million years-old PETM event (Paleocene-Eocene Thermal Maximum), lasting for about 100,000 years, driven by CO₂ levels as hugh as 1700 ppm, does not appear to have triggered a runaway greenhouse process. The PETM is attributed to ¹³C-depleted methane (Zeebe et al. 2009), reaching 5 - 8°C and leading to a mass extinction of 35-50% of benthic foraminifera. By sharp contrast, the current Anthropocene hyperthermal event, commencing with the industrial age and re-accelerating since about 1975, constitutes a temporally abrupt development exceeding the rate of geological hyperthermal events (Fig. 7), a rate which does not allow biological adaptation and thereby enhances a mass extinction of species (Barnosky et al. 2011).

Figure 7. A comparison of Cenozoic CO₂ rise rates and temperature rise rates, 
highlighting the extreme rise rates in the Anthropocene. From an earlier post
As Australia burns, the IPCC maintains there is time left to consume a carbon budget and to keep handing out offsets and carbon credits and at the 25th meeting of the Conference of the Parties to the United Nations Convention on Climate Change in Madrid, Australia is seeking to use "carry-over credits" to meet its pledged emissions reductions. The situation is illustrated by Sam Carana in the image below.



Links

• The RCP greenhouse gas concentrations and their extensions from 1765 to 2300, by Malte Meinshausen et al. (2011)
https://link.springer.com/article/10.1007/s10584-011-0156-z

• Contributions to accelerating atmospheric CO₂ growth from economic activity, carbon intensity, and efficiency of natural sinks, by J. Canadell et al. (2007)
https://www.pnas.org/content/104/47/18866

• Planetary ‘Runaway Greenhouse’ Climates More Easily Triggered than Previously Thought, by Peter Kelley (2013)
https://scitechdaily.com/planetary-runaway-greenhouse-climates-more-easily-triggered-than-previously-thought

• How Likely Is a Runaway Greenhouse Effect on Earth? MIT Technology Review (2012)
https://www.technologyreview.com/s/426608/how-likely-is-a-runaway-greenhouse-effect-on-earth/

• Storms of my grandchildren: the truth about the coming climate catastrophe and our last chance to save humanity, by James Hansen (2010)
https://www.bloomsbury.com/us/storms-of-my-grandchildren-9781608195022

• The runaway greenhouse: implications for future climate change, geoengineering and planetary atmospheres, by Colin Goldblatt and Andrew Watson (2012)
https://royalsocietypublishing.org/doi/full/10.1098/rsta.2012.0004

• Low simulated radiation limit for runaway greenhouse climates, by Colin Goldblatt, et al. (2013)
https://www.nature.com/articles/ngeo1892

• Assessing “Dangerous Climate Change”: Required Reduction of Carbon Emissions to Protect Young People, Future Generations and Nature, by James Hansen et al. (2013)
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0081648

• Towards the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), by Valérie Masson-Delmotte, Panmao Zhai, Wilfran Moufouma-Okia, Anna Pirani, Jan Fuglestvedt
https://wg1.ipcc.ch/presentations/201612_Fuglestvedt_AGU_IPCC.pdf

• Global Carbon Project, Carbon Budget 2019, press release
https://www.globalcarbonproject.org/carbonbudget/19/files/Norway_CICERO_GCB2019.pdf

• Potential emissions of CO₂ and methane from proved reserves of fossil fuels: An alternative analysis, by Richard Heede and Naomi Oreskes
https://www.sciencedirect.com/science/article/pii/S0959378015300637

• A rise of 18°C or 32.4°F by 2026?
https://arctic-news.blogspot.com/2019/02/a-rise-of-18c-or-324f-by-2026.html

• Arctic Methane Impact
https://arctic-news.blogspot.com/2013/11/arctic-methane-impact.html

• A record CO2 rise rate since the KT dinosaur extinction 66 million years ago
http://arctic-news.blogspot.com/2019/11/a-record-co2-rise-rate-since-kt-dinosaur-extinction-66-million-years-ago.html


[Author: Sam Carana] [Category: Andrew Glikson, Arctic, extinction, hydrates, methane, PETM, runaway warming]

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[l] at 11/27/19 4:00am
The UNEP just released its annual Emissions Gap Report, warning that even if all current unconditional commitments under the Paris Agreement are implemented, temperatures are expected to rise by 3.2°C, bringing even wider-ranging and more destructive climate impacts.

Indeed, the rise in greenhouse gas levels appears to be accelerating, despite pledges made under the Paris Agreement to holding the increase in the global average temperature to well below 2°C above pre-industrial levels and pursuing efforts to limit the temperature increase to 1.5°C above pre-industrial levels.

The World Meteorological Organization (WMO) reported carbon dioxide (CO₂) concentrations for 2018 of 407.8 ppm (parts per million). The WMO added that CO₂ levels, as well as methane and nitrous oxide levels, had all surged by higher amounts than during the past decade.

As the image below shows, a trend based on NOAA March 1958 through October 2019 monthly mean CO₂ data at Mauna Loa points at CO₂ levels crossing the 415 ppm mark in 2020, when an El Niño is forecast to come, as discussed in an earlier post.


The added trend in the image points at CO₂ levels crossing 1200 ppm before the end of the century, triggering the cloud feedback tipping point that by itself could push up global temperatures by 8°C, within a few years. Importantly, the clouds feedback starts at 1200 ppm CO₂-equivalent. Besides a CO₂ rise, further elements could contribute to the 1200 ppm CO₂e tipping point getting reached, such as albedo changes due to disappearing Arctic sea ice and seafloor methane releases from a rapidly-warming Arctic Ocean.

In conclusion, a huge temperature rise could eventuate much earlier than by the end of the century. As discussed in the earlier post, the 2020 El Niño could be the catalyst triggering huge methane releases from the Arctic Ocean seafloor starting in 2020 and resulting in an 18°C (or 32.4°F) temperature rise within a few years time.

In the video below, John Davis discribes some of the extreme weather events that he experienced recently.



The situation is dire and calls for comprehensive and effective action, as described in the Climate Plan.


Links

• UN news release
https://www.unenvironment.org/news-and-stories/press-release/cut-global-emissions-76-percent-every-year-next-decade-meet-15degc

• Paris Agreement
https://unfccc.int/process-and-meetings/the-paris-agreement/the-paris-agreement

• United Nations Environment Programme (UNEP) - Emissions Gap Report
https://www.unenvironment.org/resources/emissions-gap-report-2019

• WMO - Greenhouse gas concentrations in atmosphere reach yet another high
https://public.wmo.int/en/media/press-release/greenhouse-gas-concentrations-atmosphere-reach-yet-another-high

• NOAA Trends in Atmospheric Carbon Dioxide
https://www.esrl.noaa.gov/gmd/ccgg/trends/data.html

• Most Important Message Ever
https://arctic-news.blogspot.com/2019/07/most-important-message-ever.html

• 2020 El Nino could start 18°C temperature rise
https://arctic-news.blogspot.com/2019/11/2020-el-nino-could-start-18-degree-temperature-rise.html

• Climate Plan
https://arctic-news.blogspot.com/p/climateplan.html





[Author: Sam Carana] [Category: carbon dioxide, CO₂, John Davis, methane]

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[l] at 11/24/19 9:01pm
By Andrew Glikson
Earth and climate scientist
Australian National University



Since its inception the Paris Agreement has been in question due to, among other:
  • its broad definition, specifically holding the increase in the global average temperature to well below 2°C above pre-industrial levels and pursuing efforts to limit the temperature increase to 1.5°C above pre-industrial levels;
  • its non-binding nature; and 
  • accounting tricks by vested interests.
The goal assumes pre-determined limits can be placed on greenhouse gas levels and temperatures beyond which they would not continue to rise. Unfortunately these targets do not appear to take account of the amplifying positive feedback effects from land and oceans under the high cumulative greenhouse gas levels and their warming effects. Thus unfortunately the current high CO₂ levels of about 408 ppm and near-500ppm CO₂-equivalent (CO₂+methane+nitrous oxide) would likely continue to push temperatures upwards.

Significant climate science evidence appears to have been left out of the equation. The accord hinges on the need to reduce emissions, which is essential, but it does not indicate how further temperature rise can be avoided under the conditions of a high-CO₂ atmosphere, which triggers carbon release, unless massive efforts at sequestration (drawdown) of greenhouse gases are undertaken. Inherent in global warming are amplifying positive feedbacks, including albedo (reflection) decline due to the melting of ice and the opening of dark water surfaces, increased water vapor contents of the atmosphere in tropical regions which enhances the greenhouse effect, reduced sequestration of CO₂ by the warming oceans, desiccation of vegetation, fires, release of methane from permafrost and other processes. This means that even abrupt reductions in emissions may not be sufficient to stem global warming, unless accompanied by sequestration of greenhouse gases from the atmosphere to a lower level, recommended as below 350 ppm CO₂ by James Hansen, the leading climate scientist.

The world is on track to produce 50% more fossil fuels than can be burned before reaching the limit prescribed by the Paris Agreement, with currently planned coal, oil and gas outputs making the Paris Agreement goal impossible. Projected fossil fuel production in 2030 being more than is consistent with 2°C, and 120% more than that for 1.5°C.

Unbelievably, according to the International Monetary Fund, “In 2017 the world subsidized fossil fuels by $5.2 trillion, equal to roughly 6.5% of global GDP”, which is more than the total the world spends on human health. Such subsidies cannot possibly be consistent with the Paris Agreement. The pledge to end fossil fuel subsidies by 2025 by the G7 nations, with exceptions by the UK and Japan, may come too late as global CO₂ concentrations, already intersecting the stability limits of the Greenland and Antarctic ice sheets, are rising at a rate of 2 to 3 ppm per year, the highest in many millions of years.

Despite the scientific consensus regarding the anthropogenic origin of global warming, the world’s biggest fossil fuel corporations are taking a defiant stance against warnings that reserves of coal, oil and gas are already several times larger than can be burned if the world’s governments are to meet their pledge to tackle climate change. ExxonMobil said new reserves in the Arctic and Canadian tar sands must be exploited. Peabody Energy, the world’s largest private coal company, said global warming was “an environmental crisis predicted by flawed computer models”. Glencore Xstrata said that governments would fail to implement measures to cut carbon emissions. The World Bank and Bank of England have already warned of the “serious risk” climate action poses to trillions of dollars of fossil fuel assets.

Not to mention the risks to the living Earth and its billions of inhabitants!

The apparent neglect of scientific advice is not an isolated instance. It is not uncommon that climate reports are dominated by the views of economists, lawyers, bureaucrats and politicians, often overlooking the evidence presented by some of the world’s highest climate science authorities. Whereas the IPCC reports include excellent and comprehensive summaries of the peer-reviewed literature, the summaries for policy makers only partly represent the evidence and views of scientific authorities in the field, including those who have identified global warming in the first place.
Figure 2. from: James Hansen, data through June 2019
There exists a tendency in the media to report averages, such as average global temperature values, rather than the increasingly-common high zonal, regional and local anomalies.

For example, the annual mean global temperature rise of for 2018 is about one third the Arctic mean temperature rise (Fig. 2). Given that developments in the Arctic bear major consequences for climate change, the global mean  does not represent the seriousness of the climate crisis.

Another example is the way extremes weather events are reported as isolated instances, neglecting the rising frequency and intensity of hurricanes, storms, fires and droughts, indicated in frequency plots (Fig 3.).

Figure 3. Rise in geophysical, meteorological, hydrologocal and climatological events. Munich RE It is not until international and national institutions take full account of what climate science is indicating that a true picture of the climate crisis will be communicated to the public.


Andrew Glikson Dr Andrew Glikson
Earth and climate scientist
Australian National University


Books:
- The Archaean: Geological and Geochemical Windows into the Early Earth
- The Asteroid Impact Connection of Planetary Evolution
- Asteroids Impacts, Crustal Evolution and Related Mineral Systems with Special Reference to Australia
- Climate, Fire and Human Evolution: The Deep Time Dimensions of the Anthropocene
- The Plutocene: Blueprints for a Post-Anthropocene Greenhouse Earth
- Evolution of the Atmosphere, Fire and the Anthropocene Climate Event Horizon
- From Stars to Brains: Milestones in the Planetary Evolution of Life and Intelligence

[Author: Sam Carana] [Category: 1.5°C, Andrew Glikson, Arctic, CO₂, drawdown, feedbacks, fossil fuel, methane, Paris Agreement, permafrost, subsidies]

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[l] at 11/17/19 8:46pm

On November 16, 2019, there was little sea ice between Greenland and Svalbard. For reference, the image below has been added, showing coastlines for the same area.


The image below shows temperatures north of 80°N. The red line on the image shows the 2019 daily mean temperature up to November 16, 2019. The temperature is now well above the 1958-2002 mean (green line). The image also shows the freezing point of fresh water (273.15K, 0°C or 32°F, blue line).

The freezing point for salt water is lower, at around -2°C, or 28.4°F, or 271.2°K. In other words, a rise in the salt content of the water alone can make ice melt, i.e. even when the temperature of the water doesn't rise.


The image below shows that Arctic sea ice volume has been at record low levels for the time of year for some time.

As the image below shows, Arctic sea ice extent in the Chukchi Sea is currently very low.

[ image by Zack Labe, uploaded November 13, 2019 ]
The situation is dire and calls for comprehensive and effective action, as described in the Climate Plan.


Links

• Climate Plan
https://arctic-news.blogspot.com/p/climateplan.html

• 2020 El Nino could start 18 °C  temperature rise
https://arctic-news.blogspot.com/2019/11/2020-el-nino-could-start-18-degree-temperature-rise.html

• Critical Tipping Point Crossed In July 2019
https://arctic-news.blogspot.com/2019/09/critical-tipping-point-crossed-in-july-2019.html

• Most Important Message Ever
https://arctic-news.blogspot.com/2019/07/most-important-message-ever.html

• When will we die?  https://arctic-news.blogspot.com/2019/06/when-will-we-die.html

• Arctic Ocean overheating
https://arctic-news.blogspot.com/2019/09/arctic-ocean-overheating.html

• How extreme will it get?
https://arctic-news.blogspot.com/2012/07/how-extreme-will-it-get.html

• Warning Signs
https://arctic-news.blogspot.com/2018/03/warning-signs.html



[Author: Sam Carana] [Category: Arctic, extent, ocean, rise, sea ice, temperature, volume]

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[l] at 11/17/19 8:46pm
[ click on image to enlarge ] Above image shows a blue long-term trend, based on NASA LOTI 1880-Oct.2019 data, 0.78°C adjusted to reflect ocean air temperatures (as opposed to sea surface temperatures), to reflect a higher polar anomaly (as opposed to leaving out 'missing' data) and to reflect a 1750 baseline (as opposed to a 1951-1980 baseline).
The image also shows a red short-term trend, based on NASA LOTI 2012-Oct.2019 data, similarly adjusted and added to illustrate El Niño/La Niña variability and how El Niño could be the catalyst to trigger huge methane releases from the Arctic Ocean seafloor starting in 2020 and resulting in an 18°C (or 32.4°F) temperature rise within a few years time.

To put such a temperature rise in perspective, humans will likely go extinct with a 3°C rise, while most if not all life on Earth will go extinct at 5°C rise, as discussed in an earlier post.

The image below, from a recent study, indicates that El Niño is likely to come in 2020. 
An international team of scientists are forecasting an El Niño for 2020. "The probability of 'El Niño' coming in 2020 is around 80%", says Hans Joachim Schellnhuber, Director Emeritus of the Potsdam Institute for Climate Impact Research.


Above image shows NOAA's monthly global temperature anomaly from the 20th century average, colored by the El Niño - Southern Oscillation (ENSO) phenomenon.

As the NASA map below shows, heating in October 2019 was particularly pronounced over the Arctic Ocean.


Note that the above NASA map shows anomalies from a 1951-1980 baseline.

As the image below shows, just the existing carbon dioxide and methane, plus seafloor methane releases, would suffice to trigger the clouds feedback tipping point to be crossed that by itself could push up global temperatures by 8°C, within a few years.


As described in this post and in an earlier post, a rapid temperature rise could result from a combination of elements, including albedo changes, loss of sulfate cooling, and methane released from destabilizing hydrates contained in sediments at the seafloor of oceans.

[ from an earlier post ] The situation is dire and calls for comprehensive and effective action, as described in the Climate Plan.


Links

• Early warning: Physicists from Giessen, Potsdam and Tel Aviv forecast "El Niño" for 2020 — PIK Research Portal
https://www.pik-potsdam.de/news/press-releases/early-warning-physicists-from-giessen-potsdam-and-tel-aviv-forecast-el-nino-for-2020

• Very early warning signal for El Niño in 2020 with a 4 in 5 likelihood, by Josef Ludescher et al.
https://arxiv.org/abs/1910.14642

• NOAA - Monthly temperature anomalies versus El Niño
https://www.ncdc.noaa.gov/sotc/global/201909/supplemental/page-3

• NASA - GISS Surface Temperature Analysis (GISTEMP v4)
https://data.giss.nasa.gov/gistemp/maps/index_v4.html

• Most Important Message Ever
https://arctic-news.blogspot.com/2019/07/most-important-message-ever.html

• Temperature
https://arctic-news.blogspot.com/p/temperature.html

• How Much Warming Have Humans Caused?
https://arctic-news.blogspot.com/2016/05/how-much-warming-have-humans-caused.html

• It could be unbearably hot in many places within a few years time
https://arctic-news.blogspot.com/2016/07/it-could-be-unbearably-hot-in-many-places-within-a-few-years-time.html

• Peaks Matter
https://arctic-news.blogspot.com/2018/08/peaks-matter.html

• Extinction Alert
https://arctic-news.blogspot.com/2019/02/extinction-alert.html

• Climate Plan
https://arctic-news.blogspot.com/p/climateplan.html



[Author: Sam Carana] [Category: 18°C, Arctic, clathrates, El Niño, hydrates, methane, ocean, rise, temperature]

[*] [+] [-] [x] [A+] [a-]  
[l] at 11/16/19 4:49am
[ click on image to enlarge ] Above image shows a blue long-term trend, based on NASA LOTI 1880-Oct.2019 data, 0.78°C adjusted to reflect ocean air temperatures (as opposed to sea surface temperatures), to reflect a higher polar anomaly (as opposed to leaving out 'missing' data) and to reflect a 1750 baseline (as opposed to a 1951-1980 baseline).
The image also shows a red short-term trend, based on NASA LOTI 2012-Oct.2019 data, similarly adjusted and added to illustrate El Niño/La Niña variability and how El Niño could be the catalyst to trigger huge methane releases from the Arctic Ocean seafloor starting in 2020 and resulting in an 18°C (or 32.4°F) temperature rise within a few years time.

To put such a temperature rise in perspective, humans will likely go extinct with a 3°C rise, while most if not all life on Earth will go extinct at 5°C rise, as discussed in an earlier post
An international team of scientists are forecasting an El Niño for 2020. "The probability of 'El Niño' coming in 2020 is around 80%", says Hans Joachim Schellnhuber, Director Emeritus of the Potsdam Institute for Climate Impact Research.


As the image below shows, just the existing carbon dioxide and methane, plus seafloor methane releases, would suffice to trigger the clouds feedback tipping point to be crossed that by itself could push up global temperatures by 8°C, within a few years.


As described in this post and in an earlier post, a rapid temperature rise could result from a combination of elements, including albedo changes, loss of sulfate cooling, and methane released from destabilizing hydrates contained in sediments at the seafloor of oceans.

[ from an earlier post ] The situation is dire and calls for comprehensive and effective action, as described in the Climate Plan.


Links

• Early warning: Physicists from Giessen, Potsdam and Tel Aviv forecast "El Niño" for 2020 — PIK Research Portal
https://www.pik-potsdam.de/news/press-releases/early-warning-physicists-from-giessen-potsdam-and-tel-aviv-forecast-el-nino-for-2020

• Very early warning signal for El Niño in 2020 with a 4 in 5 likelihood, by Josef Ludescher et al.
https://arxiv.org/abs/1910.14642

• Another exceptional month for global average temperatures, Copernicus Climate Change Service, ECMWF
https://climate.copernicus.eu/another-exceptional-month-global-average-temperatures

• July matched, and maybe broke, the record for the hottest month since analysis began
https://public.wmo.int/en/media/news/july-matched-and-maybe-broke-record-hottest-month-analysis-began

• NOAA Global Climate Report - July 2016
https://www.ncdc.noaa.gov/sotc/global/201607

• July 2019 Global Temperature Update, by James Hansen
http://www.columbia.edu/~mhs119/Temperature/Emails/July2019.pdf

• An emerging tropical cyclone–deadly heat compound hazard, by Tom Matthews et al. (2019)
https://www.nature.com/articles/s41558-019-0525-6

• Most Important Message Ever
https://arctic-news.blogspot.com/2019/07/most-important-message-ever.html

• Temperature
https://arctic-news.blogspot.com/p/temperature.html

• How Much Warming Have Humans Caused?
https://arctic-news.blogspot.com/2016/05/how-much-warming-have-humans-caused.html

• It could be unbearably hot in many places within a few years time
https://arctic-news.blogspot.com/2016/07/it-could-be-unbearably-hot-in-many-places-within-a-few-years-time.html

• Peaks Matter
https://arctic-news.blogspot.com/2018/08/peaks-matter.html

• Extinction Alert
https://arctic-news.blogspot.com/2019/02/extinction-alert.html

• Climate Plan
https://arctic-news.blogspot.com/p/climateplan.html



[Author: Sam Carana] [Category: 18°C, Arctic, clathrates, El Niño, hydrates, methane, ocean, rise, temperature]

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[l] at 11/14/19 7:44pm
Andrew Glikson Earth and climate scientist Australian National University 15.11.2019
The effects of encroaching deserts and of fire storms on terrestrial forests originally developed under moderate conditions distinct from those emerging under rapid global warming and extreme weather events may have been underestimated. Average global temperatures do not tell the story — it is the increasingly frequent weather anomalies which do. Powerful psychological factors prevent many scientists from expressing their worst fears, a phenomenon dubbed as “scientific reticence”.

As the tropical climate zones expand toward the poles, moderate climate zones shift polar-ward and are contracting where they clash with polar-derived cold air and ice melt water flow through weakened jet stream boundaries. As climate zones are shifting at a rate of 56-111 km per decade and ecosystems have only a short time to adapt, arid zones expand and draughts of fires consume the moderate-climate forests and formerly fertile habitats. Allen et al. (2012) suggest the increase in black carbon aerosols and tropospheric ozone constitute significant factors generating a polar-ward shift of moderate climate zones.

Global fire maps by NASA document the progression of wildfires since about 2000, including major fires in Siberia, northwest Europe, southern Europe, Russia, Southeast Asia, Australia, central and southern America, California and elsewhere (Fig. 1).

Figure 1. The Moderate Resolution Imaging Spectro-radiometer (MODIS) on NASA's Terra satellite showing fires around the world. Credit: NASA Some of the global patterns that appear in the fire maps are the result of natural cycles of rainfall, dryness, and lightning. For example, naturally-occurring fires are common in the boreal forests of Canada in the summer. In other parts of the world, the patterns are the result of human activity. For example, the intense burning in the heart of South America from August-October is a result of human-triggered fires, both intentional and accidental.

Many scientists and the IPCC have underestimated the scale and rate of global warming and its consequences. With exceptions, the need for excessive caution and absolute certainty in science is often manifested in reticence from the mainstream science (‘Down to Earth’ 2019). However, the available evidence suggests that scientists have in fact been conservative in their projections of the impacts of climate change and at least some of the key attributes of global warming from increased atmospheric greenhouse gases have been underpredicted, particularly in IPCC assessments of the physical science by Working Group I.

By contrast, at a speed hardly anticipated about 20 years ago, wildfires have been spreading around the globe over large parts of the continents.

Nor do average global land-ocean temperatures tell the whole story. It is the increasingly frequent anomalies which underlie extreme weather events (Fig. 2), including rapid Arctic melt, heatwaves, fires, storms and cyclones, which underpin the fundamental shift in the state of the terrestrial climate.

Figure 2. Temperature anomaly distribution: The frequency of occurrence (vertical axis) of local temperature anomalies (relative to 1951-1980 mean) in units of local standard deviation (horizontal axis). Area under each curve is unity. Image credit: NASA/GISS. It has been stated “What happens in the Arctic doesn't stay in the Arctic”. Temperatures in the Arctic have reached 34°C in July 2019, affecting melting over 700,000 km² in Greenland late May 2019. The weakening of the circum-Arctic jet stream ensues in its undulation and intersection by warm air masses moving north and by cold air masses moving south, along with ice melt from the Greenland ice sheet forming cold regions in the North Atlantic Ocean.

Figure 3. Weather systems driven by the 
strong westerly winds of the Antarctic 
polar vortex curl over the southern 
continents (NASA, Galileo). According to the Australian Climate Council, climate change has contributed to a southward shift in weather systems that typically bring cool season rainfall to southern Australia. As the cold humid spirals of the Antarctic vortex (Fig. 3) recede to the south, since the 1970s late autumn and early winter rainfall has decreased by 15% in southeast Australia, and Western Australia’s southwest region. Current drought conditions come after a 2016/2017 and 2018 Summer characterized by record-breaking temperatures, followed by a record dry winter. Rainfall over southern Australia during autumn 2018 was the second lowest on record (Fig. 4). The drought has reached extreme level, accompanied by wildfires. Australia, like other parts of the world, is paying the price of climate change in terms of growing damage to its agriculture, communities and way of life.

Figure 4. Australia: Current effects of global warming. 
A. 2018 annual mean temperatures compared to historical temperature observations. 
B. 2018 annual rainfall compared to historical rainfall observations. The global rise rate in CO₂ has reached 2 to 3 ppm/year, the fastest rate since 66 million years ago, and a level of CO₂-equivalent (a value including the radiative forcing of methane and nitrous oxide) near 500 ppm. According to the IMF (2017), the world is subsidizing fossil fuels by $5.2 trillion, equal to roughly 6.5% of global GDP. By contrast, the loss of wealth due to reduced agricultural productivity due to climate change is projected to exceed $19 billion by 2030, $211 billion by 2050 and a projected $4 trillion by 2100.

Figure 5. Fires in Australia, November 8, 2019, NASA Worldview  As stated by Hansen et al. (2012): “Burning all fossil fuels would create a different planet than the one that humanity knows. The palaeoclimate record and ongoing climate change make it clear that the climate system would be pushed beyond tipping points, setting in motion irreversible changes, including ice sheet disintegration with a continually adjusting shoreline, extermination of a substantial fraction of species on the planet, and increasingly devastating regional climate extremes”.


Andrew Glikson Dr Andrew Glikson
Earth and climate scientist
Australian National University



Books:
The Archaean: Geological and Geochemical Windows into the Early Earth
The Asteroid Impact Connection of Planetary Evolution
The Plutocene: Blueprints for a Post-Anthropocene Greenhouse Earth
Evolution of the Atmosphere, Fire and the Anthropocene Climate Event Horizon
Asteroids Impacts, Crustal Evolution and Related Mineral Systems with Special Reference to Australia
Climate, Fire and Human Evolution: The Deep Time Dimensions of the Anthropocene
From Stars to Brains: Milestones in the Planetary Evolution of Life and Intelligence



[Author: Sam Carana] [Category: Andrew Glikson, Australia, drought, fire, rise, temperature]

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[l] at 11/6/19 12:31am
By Andrew Glikson
Earth and climate scientist
Australian National University
As the concentration of atmospheric CO₂ has risen to 408 ppm and the total greenhouse gas level, including methane and nitrous oxide, combine to near 500 parts per million CO₂-equivalent, the stability threshold of the Greenland and Antarctic ice sheets, currently melting at an accelerated rate, has been exceeded. The consequent expansion of tropics and the shift of climate zones toward the shrinking poles lead to increasingly warm and dry conditions under which fire storms, currently engulfing large parts of South America (Fig. 1), California, Alaska, Siberia, Sweden, Spain, Portugal, Greece, Angola, Australia and elsewhere have become a dominant factor in the destruction of terrestrial habitats.

Figure 1. Sensors on NASA satellites Terra and Aqua captured a record of thousands of points
of fire in Brazil in late August. Credit: NASA Earth Observatory Since the 18th century, combustion of fossil fuels has led to the release of more than 910 billion tons of carbon dioxide (GtCO₂) by human activity, raising CO₂ to about 408.5 ppm (Fig. 2), as compared to the 280-300 ppm range prior to the onset of the industrial age. By the early-21st century the current CO₂ rise rate has reached of 2 to 3 ppm/year.

Figure 2. Global temperature and carbon dioxide - Climate Central Allowing for the transient albedo enhancing effects of sulphur dioxide and other aerosols, mean global temperature has potentially reached ~2.0 degrees Celsius above pre-industrial temperatures. Current greenhouse gas forcing and global mean temperatures are approaching Miocene-like (5.3-23 million years-ago) composition.

The current carbon dioxide rise rate exceeds the fastest rates estimated for the K-T asteroid impact (66.4 million years-ago) and the PETM (Paleocene-Eocene Temperature Maximum) hyperthermal event (55.9 million years ago) by an order of magnitude (Fig. 3). The current growth rate of atmospheric greenhouse gases, in particular over the last 70 years or so, may appear gradual in our lifetime, but it constitutes an extreme event in the recorded history of Earth.
Figure 3. Cenozoic CO₂ and temperature rise rates. Current rise rates of CO₂ ( 2.86 ppm CO2/year) and temperature (0.15-0.20°C per decade since 1975) associated with extreme weather events raise doubt regarding gradual linear climate projections. Instead, chaotic climate conditions may arise from the clash between northward-shifting warm air masses which intersect the weakened undulating Arctic jet stream boundary and freezing polar air fronts penetrating Siberia, North America and Europe. The definition of a “tipping point” in the climate system is a threshold which, once exceeded, can lead to large changes in the state of the system, or where the confluence of individual factors combines into a single stream. The term “tipping element” describes subcontinental-scale subsystems of the Earth system that are susceptible to being forced into a new irreversible state by small perturbations. In so far as a tipping point can be identified in current developments of the climate system, the weakening of the Arctic boundary, indicated by slowing down and increased disturbance of the jet stream heralds a likely tipping point, an example being the recent ‘Beast from the East” freeze in northern Europe and North America (Fig. 4).

Figure 4. The cold fronts penetrating Europe from Siberia and the North Atlantic and North America from the Arctic, 2018. UK Met Office. A report by the National Academy Press 2011 states: “As the planet continues to warm, it may be approaching a critical climate threshold beyond which rapid (decadal-scale) and potentially catastrophic changes may occur that are not anticipated.”

Direct evidence for changing climate patterns is provided by the expansion of the tropics and migration of climate zones toward the poles, estimated at a rate of approximately 56-111 km per decade. As the dry subtropical zones shift toward the poles, droughts worsen and overall less rain falls in temperate regions. Poleward shifts in the average tracks of tropical and extratropical cyclones are already happening. This is likely to continue as the tropics expand further. As extratropical cyclones move, they shift rain away from temperate regions that historically rely on winter rainfalls for their agriculture and water supply. Australia is highly vulnerable to expanding tropics as about 60 percent of the continent lies north of 30°S.

Low-lying land areas, including coral islands, delta and low coastal and river valleys would be flooded due to sea level rise to Miocene-like (5.3-23 million years ago) sea levels of approximately 40±15 meters above pre-industrial levels. Accelerated flow of ice melt water flow from ice sheets into the oceans is reducing temperatures over tracts in the North Atlantic and circum-Antarctic oceans. Strong temperature contrasts between cold polar-derived fronts and warm tropical-derived air masses lead to extreme weather events, retarding habitats, in particular over coastal regions. As partial melting of the large ice sheets proceeds the Earth’s climate zones continue to shift polar-ward (Environmental Migration Portal, 2015). This results in an expansion of tropical regions such as existed in the Miocene, reducing the size of polar ice sheets and temperate climate zones.

According to Berger and Loutre (2002) the effect of high atmospheric greenhouse gas levels would delay the next ice age by tens of thousands of years, during which chaotic tropical to hyper-tropical conditions including extreme weather events would persist over much of the Earth, until atmospheric CO₂ and insolation subside. Humans are likely to survive in relatively favorable parts of Earth, such as sub-polar regions and sheltered mountain valleys, where cooler conditions would allow flora and fauna to persist.

To try and avoid a global calamity, abrupt reduction in carbon emissions is essential, but since the high level of CO₂-equivalent is activating amplifying feedbacks from land and ocean, global attempts to down-draw about of 50 to 100 ppm of CO₂ from the atmosphere, using every effective negative emissions, is essential. Such efforts would include streaming air through basalt and serpentine, biochar cultivation, sea weed sequestration, reforestation, sodium hydroxide pipe systems and other methods.

But while $trillions continue to be poured into preparation of future wars, currently no government is involved in any serious attempt at the defense of life on Earth.


Andrew Glikson Dr Andrew Glikson
Earth and climate scientist
Australian National University

Books:

- The Archaean: Geological and Geochemical Windows into the Early Earth
- The Asteroid Impact Connection of Planetary Evolution
- Asteroids Impacts, Crustal Evolution and Related Mineral Systems with Special Reference to Australia
- Climate, Fire and Human Evolution: The Deep Time Dimensions of the Anthropocene
- The Plutocene: Blueprints for a Post-Anthropocene Greenhouse Earth
- Evolution of the Atmosphere, Fire and the Anthropocene Climate Event Horizon
- From Stars to Brains: Milestones in the Planetary Evolution of Life and Intelligence


[Author: Sam Carana] [Category: Andrew Glikson, CO₂, feedbacks, global, greenhouse gas, rate, rise]

[*] [+] [-] [x] [A+] [a-]  
[l] at 10/21/19 7:21am
In many countries, it has been proven hard to implement policies that help electric vehicle (EVs). In France, fuel taxes have triggered huge protests. In Ecuador, huge protests followed a steep rise in fuel prices, as a result of a decision to end gasoline and diesel subsidies.

An analysis conducted by Arctic-news compares eight policies on two criteria, i.e. how effective they are from a policy perspective and how popular the policies will likely be. As the image below shows, many policies are little or no better at helping EVs than continuing with business as usual (BAU).


“Tightening fuel economy standards may aim to reduce fuel use,” says Sam Carana, editor of Arctic-news, “but the Jevons paradox shows that this may lead to people buying more powerful cars, drive longer distances, etc. Moreover, it does little to help EVs, in fact, it may make it cheaper for people to keep driving fossil fuel-powered cars.

Sam Carana adds: “Subsidies for EVs aren't popular with pedestrians and cyclists, or with people who use public transport to go to work. These are often the poorest people and they feel that money that is spent on subsidies for EVs comes at the expense of social services for the poor. Subsidies are unlikely to gain popular support. Similarly, when subsidies for EVs take the form of tax deductions given to EV buyers, this mainly benefit those who can afford to buy EVs. Additionally, this reduces overall tax revenue, leaving less money for social services.”

“Taxes aren't much better, they may make driving a polluting car more expensive, but as long as people keep driving polluting cars, it won't help EVs and it won't help much with the climate crisis either. Higher taxes on fuel and cars haven't made EVs much more common in Europe than they are in the U.S., where such taxes are lower. The worst form of tax is 'Cap & Trade', as it enables people to keep driving polluting cars by paying for emission cuts elsewhere. Even if those cuts are indeed made elsewhere, they aren't made locally. Tax and Dividend seeks to get popular support by promising people part of the revenue, but this means the money isn't used to fight pollution and it may even be counterproductive, by helping people to keep driving fossil fuel-powered cars. Simple carbon taxes therefore seem more effective, while they may also be more popular with the poor, since more of the revenues can be spent on social services.”

Sam Carana: “Local feebates are the best way to go. It makes sense to add fees to the price of fuel, and - in order to most effectively facilitate the necessary transition to EVs - the revenues are best used to support EVs locally, which also helps such polices gain popular support locally.

The analysis also looks at wider sets of local feebates, such as fees on sales of fossil fuel-powered cars, with the revenues used to fund rebates on local sales of EVs. Fees on facilities that sell of process fuel could also raise revenues that could be used to fund rebates on, say, EV chargers.  Furthermore, differentiation in fees on car registration, on car parking and on road toll could all help make EVs more attractive.

In conclusion, a wide set of local feebates can most effectively facilitate the necessary changes and can best gain local support. The climate crisis urgently needs comprehensive and effective action, as described in the Climate Plan, which recommends implementation of local feebates to facilitate the necessary changes.


Links

• Climate Plan
https://arctic-news.blogspot.com/p/climateplan.html

• Feebates
https://arctic-news.blogspot.com/p/feebates.html

• Who are the gilets jaunes and what do they want?
https://www.theguardian.com/world/2018/dec/03/who-are-the-gilets-jaunes-and-what-do-they-want

• Ecuador's Morena scraps fuel subsidy cuts in big win for indigenous groups
https://www.reuters.com/article/us-ecuador-protests/ecuadors-moreno-scraps-fuel-subsidy-cuts-in-big-win-for-indigenous-groups-idUSKBN1WT265

• Ecuador’s Government Crisis, Explained
https://www.washingtonpost.com/business/energy/ecuadors-government-crisis-explained/2019/10/08/d54f19f2-ea17-11e9-a329-7378fbfa1b63_story.html

• What's happening in Ecuado? Protests over fuel subsidies reach sixth day
https://nacla.org/news/2019/10/14/ecuador-societys-reaction-imf-austerity-package-indigenous

• The Jevons Paradox
https://en.wikipedia.org/wiki/Jevons_paradox



[Author: Sam Carana] [Category: cars, economy, effective, efficiency, feebates, fuel, policies, popular support, subsidies, tax]

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[l] at 10/14/19 8:52am

In July 2019, a critical tipping point was crossed. July sea surface temperatures on the Northern Hemisphere were 1.07°C above what they were during the 20th century, as illustrated by above image which has a trend added that points at 5°C above the 20th century by 2033.

Why is 1°C above 20th century's temperature such a critical tipping point for the sea surface on the Northern Hemisphere? Let's first take a look at where global heating is going.



Oceans are absorbing over 90% of global heating, as illustrated by above image. Due to the high greenhouse gas levels resulting from people's emissions, oceans keep on getting hotter, and given oceans' huge heat-absorbing capacity, it has taken many years before this tipping point was crossed.

In July 2016, the tipping point was touched at 0.99°C. In July 2017, the July temperature anomaly was on the tipping point, at exactly 1°C. In July 2018, the sea surface was a bit cooler, and the tipping point was crossed in July 2019 when the temperature anomaly was 1.07°C above the 20th century average.


Arctic sea ice used to absorb 0.8% of global heating (in 1993 to 2003). Ocean heat keeps flowing into the Arctic Ocean, carried by ocean currents, as illustrated by above image. As peak heat arrives in the Arctic Ocean, it melts sea ice from below.

The image below shows sea surface temperatures on August 13, 2019 (left) and on September 9, 2019 (right). The light blue line forms a line indicating the sea surface temperature there is 0°C. That light blue line has moved pole-ward in September, due to rivers that kept adding warm water and also due to more warmer water entering the Arctic Ocean from the Atlantic Ocean and the Pacific Ocean.


As above image also shows, the sea surface near Svalbard was 20.4°C (or 68.7°F) at the area marked by the green circle on August 13, 2019 (left), and 20.3°C (or 68.5°F) on September 9, 2019 (right), indicating how high the temperature of the water can be underneath the surface, as it moves into the Arctic Ocean. In other words, further ocean heat is still entering the Arctic Ocean.

From mid August 2019, ocean heat could no longer find any sea ice to melt, since the thick sea ice that hangs underneath the surface had already disappeared. A thin layer of sea ice at the surface was all that remained, as air temperatures didn't come down enough to melt it from above.


This indicates that the buffer has gone that has until now been consuming ocean heat as part of the melting process. As long as there is sea ice in the water, this sea ice will keep absorbing heat as it melts, so the temperature will not rise at the sea surface. The amount of energy absorbed by melting ice is as much as it takes to heat an equivalent mass of water from zero to 80°C.

The image below, created with NOAA 2007-2019 June-August sea surface temperature data, shows how extra heating of the sea surface on the Northern Hemisphere from 2012 caused the buffer to disappear and the 1°C tipping point to be crossed in 2019.


Once the buffer is gone, further heat arriving in the Arctic Ocean must go elsewhere.


The image below illustrates the difference in extent between the years, as recorded by ads.nipr.ac.jp. On September 13, 1980, Arctic sea ice extent was 7.77 million km². On September 17, 2019, Arctic sea ice extent was 3.96 million km². On September 16, 2012, extent was 3.18 million  million km².


Arctic sea ice will soon be growing in extent, sealing off the water, meaning that less ocean heat will be able to escape to the atmosphere.


This situation comes at a time that methane levels are very high globally. Mean global methane levels were as high as 1911 parts per billion on September 3, 2019, as discussed in a recent post. This post, as well as many earlier posts, also discussed the danger that ocean heat will reach sediments at the seafloor of the Arctic Ocean and cause huge methane releases.

Ominously, methane levels at Barrow, Alaska, were very high recently, as illustrated by above image showing methane levels peaking at over 2500 parts per billion. The satellite image below shows the global situation on the afternoon of September 13, 2019, when peak methane levels as high as 2605 ppb were recorded by the MetOp-1 satellite at 586 mb.


In the videos below, Paul Beckwith discusses the situation.

Video 1: What’s up (down) with Arctic Sea-Ice: Extent, Thickness, Volume Dynamics and Thermodynamics
Video 2: New Ice Behaviour Regime for Arctic Sea Ice Melt
Video 3: Is Climate System Internal Variability Significantly Messing with Arctic Sea Ice Demise Predictions?
Video 4: Last Remaining Arctic Sea Ice Will Likely be that Orbiting the North Pole, and NOT Along Coastlines
The situation is dire and calls for comprehensive and effective action, as described in the Climate Plan.


Links

• Climate Plan
https://arctic-news.blogspot.com/p/climateplan.html

• Arctic Sea Ice Gone By September 2019?
https://arctic-news.blogspot.com/2019/07/arctic-sea-ice-gone-by-september-2019.html

• July 2019 Hottest Month On Record
https://arctic-news.blogspot.com/2019/08/july-2019-hottest-month-on-record.html

• Cyclone over Arctic Ocean - August 24, 2019
https://arctic-news.blogspot.com/2019/08/cyclone-over-arctic-ocean-august-24-2019.html

• Most Important Message Ever
https://arctic-news.blogspot.com/2019/07/most-important-message-ever.html

• Arctic Ocean overheating
https://arctic-news.blogspot.com/2019/09/arctic-ocean-overheating.html


[Author: Sam Carana] [Category: Arctic, global, heat, heating, ocean, Paul Beckwith, sea ice, sea surface temperature, thickness, tipping point, volume]

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[l] at 10/14/19 8:12am

The Arctic Ocean is overheating, as illustrated by above image.
[ from earlier post ]
Heating of the water in the Arctic Ocean is accelerating, as illustrated by above map that uses 4-year smoothing and that shows temperatures in the Arctic that are up to 4.41°C hotter than the average global temperature during 1880-1920.

The NOAA image on the right shows the sea surface temperature difference from 1961-1990 in the Arctic at latitudes 60°N - 90°N on September 7, 2019.

Where Arctic sea ice disappears, hot water emerges on the image, indicating that the temperature of the ocean underneath the sea ice is several degrees above freezing point.

The nullschool.net image on the right shows sea surface temperature differences from 1981-2011 on the Northern Hemisphere on September 8, 2019, with anomalies reaching as high as 15.2°C or 27.4°F (near Svalbard, at the green circle).

Accelerating heating of the Arctic Ocean could make global temperatures skyrocket in a matter of years.

Decline of the sea ice comes with albedo changes and further feedbacks, such as the narrowing temperature difference between the North Pole and the Equator, which slows down the speed at which the jet stream circumnavigates Earth and makes the jet stream more wavy.


Disappearance of the sea ice also comes with loss of the buffer that has until now been consuming ocean heat as part of the melting process. As long as there is sea ice in the water, this sea ice will keep absorbing heat as it melts, so the temperature will not rise at the sea surface. The amount of energy absorbed by melting ice is as much as it takes to heat an equivalent mass of water from zero to 80°C. Once the sea ice is gone, further heat must go elsewhere.

[ click on images to enlarge ] The Naval Research Laboratory image on the right shows a forecast for Sep. 8, 2019, run on Sep. 7, 2019, of the thickness of the sea ice. Sea ice has become terribly thin, indicating that the heat buffer constituted by the sea ice has effectively gone. Only a very thin layer of sea ice remains in place throughout much of the Arctic Ocean.

This remaining sea ice is stopping a lot of ocean heat from getting transferred to the air, so the temperature of the water of the Arctic Ocean is now rising rapidly, with the danger that some of the accumulating ocean heat will reach sediments at the seafloor and cause eruptions of huge amounts of methane.


This situation comes at a time that methane levels are very high globally. Mean global methane levels were as high as 1911 parts per billion on the morning of September 3, 2019, a level recorded by the MetOp-1 satellite at 293 mb (image below).


[ from an earlier post ] As the image on the right shows, mean global levels of methane (CH₄) have risen much faster than carbon dioxide (CO₂) and nitrous oxide (N₂O), in 2017 reaching, respectively, 257%, 146% and 122% their 1750 levels.

Compared to carbon dioxide, methane is some 150 times as potent as a greenhouse gas during the first few years after release.

Huge releases of seafloor methane alone could make marine stratus clouds disappear, as described in an earlier post, and this clouds feedback could cause a further 8°C global temperature rise.

In total, global heating by as much as 18°C could occur by the year 2026 due to a combination of elements, including albedo changes, loss of sulfate cooling, and methane released from the ocean seafloor.

from an earlier post (2014)  
In the image below, a global warming potential (GWP) of 150 for methane is used. Just the existing carbon dioxide and methane, plus seafloor methane releases, would suffice to trigger the clouds feedback tipping point to be crossed that by itself could push up global temperatures by 8°C, within a few years time.


Progression of heating could unfold as pictured below.

[ from an earlier post ]
In the video below, John Doyle describes out predicament.



The situation is dire and calls for comprehensive and effective action, as described in the Climate Plan.


Links

• Climate Plan
https://arctic-news.blogspot.com/p/climateplan.html

• Arctic Sea Ice Gone By September 2019?
https://arctic-news.blogspot.com/2019/07/arctic-sea-ice-gone-by-september-2019.html

• July 2019 Hottest Month On Record
https://arctic-news.blogspot.com/2019/08/july-2019-hottest-month-on-record.html

• Cyclone over Arctic Ocean - August 24, 2019
https://arctic-news.blogspot.com/2019/08/cyclone-over-arctic-ocean-august-24-2019.html

• Most Important Message Ever
https://arctic-news.blogspot.com/2019/07/most-important-message-ever.html


[Author: Sam Carana] [Category: Arctic, change, climate, global, heating, John Doyle, methane, rise, sea ice, sea surface temperature, seafloor, temperature, thickness]

[*] [+] [-] [x] [A+] [a-]  
[l] at 10/14/19 7:07am

Above image shows temperatures north of 80°N. The red line on the image shows the 2019 daily mean temperature up to Oct 13, 2019. The temperature is now well above the 1958-2002 mean (green line). The image also shows the freezing point of water (273.15K, 0°C or 32°F, blue line).

[ click on images to enlarge ]
As above combination image shows, air temperatures are high over parts of the Arctic Ocean where there is no sea ice. This is where heat gets transferred from the Arctic Ocean to the atmosphere. The image in the left panel shows anomalies on October 14, 2019. Anomalies look set to get stronger, as illustrated by the forecast for October 24, 2019, in the right panel.

The image on the right shows sea surface temperature anomalies. On October 13, 2019, the sea surface near Svalbard was 14.7°C or 26.4°F hotter than 1981-2011.

Arctic sea ice extent is very low. As the image below shows, Arctic sea ice extent was 4.88 million km² on October 13, 2019, the lowest on record for the time of year.

[ click on image to enlarge ]
The image below shows that Arctic sea ice volume is also at record low for the time of year.


This lack of sea ice results from rising temperatures of water in the Arctic Ocean. The image below, created with NOAA 2007-2019 June-August sea surface temperature data, shows  heating of the sea surface on the Northern Hemisphere, with an ominous trend added.
[ from earlier post ] The danger is that ocean heat will reach sediments at the seafloor of the Arctic Ocean and cause huge methane releases.

The situation is dire and calls for comprehensive and effective action, as described in the Climate Plan.


Links

• Climate Plan
https://arctic-news.blogspot.com/p/climateplan.html

• Critical Tipping Point Crossed In July 2019
https://arctic-news.blogspot.com/2019/09/critical-tipping-point-crossed-in-july-2019.html

• Most Important Message Ever
https://arctic-news.blogspot.com/2019/07/most-important-message-ever.html

• Arctic Ocean overheating
https://arctic-news.blogspot.com/2019/09/arctic-ocean-overheating.html



[Author: Sam Carana] [Category: Arctic, extent, heat, methane, ocean, rise, sea ice, sea surface, temperature, volume]

[*] [+] [-] [x] [A+] [a-]  
[l] at 9/27/19 10:06am
Blueprints of future climate trends

Extreme GHG and temperature rise rates question linear climate projections

Andrew Glikson
Earth and climate scientist
Australian National University
geospec@iinet.net.au
Abstract

The extreme greenhouse gas (GHG) and temperature rise rates since the mid-1970th raise questions over linear climate projections for the 21st century and beyond. Under a rise of CO₂-equivalent reaching +500 ppm and 3.0 W/m⁻² relative to 1750, the current rise rates of CO₂ by 2.86 ppm per and recent global temperature rise rate (0.15-0.20°C per decade) since 1975 are leading to an abrupt shift in state of the terrestrial climate and the biosphere. By mid-21st century at >750 ppm CO₂-e climate tipping points indicated by Lenton et al. 2008 and Schellnhuber 2009 are likely to be crossed. Melting of the Greenland and Antarctic ice sheets has increased by a factor of more than 5 since 1979–1990. As the ice sheets and sea ice melt, the albedo flip between reflective ice surfaces and dark infrared-absorbing water results in significant increase of radiative forcing, and complete removal of Arctic sea ice would result in a forcing of about 0.7 W/m⁻² (Hudson, 2011). The confluence of climate events, including a breach of the circum-Arctic jet stream boundary and a polar-ward migration of climate zones at a rate of 56-111 km per decade, induce world-wide extreme weather events including bushfires, methane release from Arctic permafrost and sediments. For a climate sensitivity of 3±1.5°C per doubling of atmospheric CO₂, global warming has potentially reached between +2°C to +3 ° C above mean pre-industrial temperatures at a rate exceeding the fastest growth rate over the last 55 million years. As ice melt water flow into the oceans temperature polarities between warming continents and cooling tracts of ocean would further intensify extreme weather events under non-linear climate trajectories. The enrichment of the atmosphere in GHG, constituting a shift in state of the terrestrial climate, is predicted to delay the onset of the next glacial state by some 50,000 years.

GHG and temperature rise

The paleoclimate record suggests that no event since 55 million years ago, the Paleocene-Eocene Thermal Maximum (PETM), when global temperatures rose by more than +5 to +8°C over a period of ~20,000 years, with a subsequent warming period of up to 200,000 years, has been as extreme as atmospheric disruption since the onset of the industrial age about 1750 AD (the Anthropocene), accelerating since 1975. During this period greenhouse gas levels have risen from ~280 ppm to above >410 ppm and to 496 ppm CO₂-equivalent (Figure 1), the increase of CO₂ reaching near-47 percent above the original atmospheric concentration. However, linear climate change projections are rare in the recent climate history (Figure 2) and linear future climate projections may not account for the effects of amplifying feedbacks from land and oceans. Given an Anthropocene warming rate faster by ~X200 times than the PETM (Figure 3), linear warming trajectories such as are projected by the IPCC may overlook punctuated tipping points, transient reversals and stadial events.
Figure 1. Growth of CO₂-equivalent level and the annual greenhouse gas Index (NOAA AGGI).
Measurements of  CO₂  to the 1950s are from (Keeling et al., 2008) and from air trapped in ice and
snow  between  CO₂  concentrations and radiative forcing from all long-lived greenhouse gases .
According to NOAA, GHG forcing in 2018 has reached 3.101 W/m⁻² relative to 1750 (CO₂ = 2.044 W/m⁻²; CH₄ = 0.512 W/m⁻²; N₂O = 0.199 W/m⁻²; CFCs = 0.219 W/m⁻²) with a CO₂-equivalent of 492 ppm (Figure 1). The rise in GHG forcing during the Anthropocene since about 1800 AD, intensifying since 1900 AD and sharply accelerating since about 1975, has induced a mean of ~1.5°C over the continents above pre-industrial temperature, or >2.0°C when the masking role of aerosols is discounted, implying further warming is still in store.

According to Hansen et al. 2008, the rise in radiative forcing during the Last Glacial Termination (LGT - 18,000 -11,000 years BP), associated with enhancing feedbacks, has driven GHG radiative forcing by approximately ~3.0 W/m⁻² and a mean global temperature rise of ~4.5°C (Figure 2), i.e. of similar order as the Anthropocene rise since about 1900. However the latter has been reached within a time frame at least X30 times shorter than the LGT, underpinning the extreme nature of current global warming.
Figure 2. (Hansen et al. 2008). Glacial-temperature and GHG forcing for the last 420,000 years based on the Vostok
ice core, with the time scale expanded for the Anthropocoene. The ratio of temperature and forcing scales is 1.5°C
per 1 W/m⁻². The temperature scale gives the expected equilibrium response to GHG change including slow feedback
surface albedo change. Modern forcings include human-made aerosols, volcanic aerosols and solar irradiance.
The CO₂-equivalent levels and radiative forcing levels constitute a rise from Holocene levels (~280 ppm CO₂) to >410 ppm compared with Miocene-like levels (300-600 ppm CO₂), at a rate reaching 2 to 3 ppm/year, within a century or so, driving the fastest temperature rise rate recorded since 55 million years ago (Figure 3).

Figure 3. A comparison between rates of mean global temperature rise during: (1) the last Glacial Termination (after Shakun et al. 2012); (2) the PETM (Paleocene-Eocene Thermal Maximum, after Kump 2011); (3) the late Anthropocene (1750–2016), and (4) an asteroid impact. In the latter instance temperature due to CO₂ rise would lag by some weeks or months behind aerosol-induced cooling
Considering the transient mitigating albedo effects of clouds, seasonal land surface albedo, ice albedo, atmospheric aerosols including sulphur dioxide and nitrate, the potential rise of land temperature could have reached -0.4 to -0.9 W/m⁻² in 2018, masking approximately 0.6 to 1.3°C potential warming once the short lived aerosol effect is abruptly reduced.

Accelerated melting of the ice sheets

The fast rate of the Anthropocoene temperature rise compared to the LGT and PETM (Figure 3) ensues in differences in terms of the adaptation of flora and fauna to new conditions. The shift in state of the Earth’s climate is most acutely manifested in the poles, where warming leads to weakening of the jet stream boundaries which are breached by outflow of cold air fronts, such as the recent “Beast from the East” event, and penetration of warm air masses.

As the poles keep warming, to date by a mean of ~2.3 ° C, the shrinking of the ice sheets per year has accelerated by a factor of more than six fold (Figure 4). Warming of the Arctic is driven by the ice-water albedo flip, where dark sea-water absorbing solar energy alternates with high-albedo ice and snow, and by the weakening of the polar boundary and jet stream.

Greenland. The threshold of collapse of the Greenland ice sheet, retarded by hysteresis, is estimated in the range of 400-560 ppm CO₂, already transgressed at the current 496 ppm CO₂equivalent (Figure 4). The Greenland mass loss increased from 41 ± 17 Gt/yr in 1990–2000, to 187 ± 17 Gt/yr in 2000–2010, to 286 ± 20 Gt/yr in 2010–2018, or six fold since the 1980s, or 80 ± 6 Gt/yr per decade, on average.

Antarctica. The greenhouse gas level and temperature conditions under which the East Antarctic ice sheet formed during the late Eocene 45-34 million years ago are estimated as ~800–2000 ppm and up to 4 degrees Celsius above pre-industrial values, whereas the threshold of collapse is estimated as 600 ppm CO₂ or even lower. The total mass loss from the Antarctic ice sheet increased from 40 ± 9 Gt/yr in 1979–1990 to 50 ± 14 Gt/yr in 1989–2000, 166 ± 18 Gt/yr in 1999–2009, and 252 ± 26 Gt/yr in 2009–2017. Based on satellite gravity data, the East Antarctic ice sheet is beginning to breakdown in places (Jones 2019), notably the Totten Glacier (Rignot et al., 2019), which may be irreversible. According to Mengel and Levermann (2014), the Wilkes Basin in East Antarctica alone contains enough ice to raise global sea levels by 3–4 meters.

Figure 4. (A) New elevation showing the Greenland and Antarctic current state of the ice sheets accurate to a few meters in height, with elevation changes indicating melting at record pace, losing some 500 km³ of ice per-year into the oceans; (B) Ice anomaly relative to the 2002-2016 mean for the Greenland ice sheet (magenta) and Antarctic ice sheet (cyan). Data are from GRACE; (C) the melting of sea ice 1978-2017, National Snow and Ice Data Center (NCIDC)
C. Migration of climate zones

The expansion of warm tropical zones and the polar-ward migration of subtropical and temperate climate zones are leading to a change in state in the global climate pattern. The migration of arid subtropical zones, such as the Sahara, Kalahari and central Australian deserts into temperate climate zones ensues in large scale droughts, such in inland Australia and southern Africa. In the northern hemisphere expansion of the Sahara desert northward, manifested by heat waves across the Mediterranean and Europe (Figure 5).
Figure 5. (A) Migration of the subtropical Sahara climate zone (red spots) northward into the Mediterranean climate
zone leads to warming, drying and fires over extensive parts of Spain, Portugal, southern France, Italy, Greece and
Turkey, and to melting of glaciers in the Alps. Migration, Environment and Climate Change, International
Organization for Migration Geneva – Switzerland (GMT +1); Source: https://environmentalmigration.iom.int/maps
Figure 5. (B) Southward encroachment of Kalahari Desert conditions (vertical lines and red spots) leading to
warming  and drying of parts of southern Africa.  Source:  https://environmentalmigration.iom.int/maps Figure 5. (C) Drying parts of southern Australia, including Western Australia, South Australia and parts of the
eastern States, accompanied with increasing bushfires. Source: https://environmentalmigration.iom.int/maps Climate extremes

Since the bulk of terrestrial vegetation has evolved under glacial-interglacial climate conditions, where GHG range between 180 - 300 ppm CO₂, global warming is turning large parts of Earth into a tinderbox, ignited by natural and human agents. By July and August 2019, as fires rage across large territories, including the Amazon forest, dubbed the Planet’s lungs as it enriches the atmosphere in oxygen. When burnt the rainforest becomes of source of a large amount of CO₂ (Figure 6.B), with some 72,843 fires in Brazil this year and extensive bushfires through Siberia, Alaska, Greenland, southern Europe, parts of Australia and elsewhere, the planet’s biosphere is progressively transformed. As reported: ‘Climate change is making dry seasons longer and forests more flammable. Increased temperatures are also resulting in more frequent tropical forest fires in non-drought years. And climate change may also be driving the increasing frequency and intensity of climate anomalies, such as El Niño events that affect fire season intensity across Amazonia.’

Extensive cyclones, floods, droughts, heat waves and fires (Figure 6.B) increasingly ravage large tracts of Earth. However, despite its foundation in the basic laws of physics (the black body radiation laws of Planck, Kirchhoff' and Stefan Boltzmann), as well as empirical observations around the world by major climate research bodies (NOAA, NASA, NSIDC, IPCC, World Meteorological Organization, Hadley-Met, Tindale, Potsdam, BOM, CSIRO and others), the anthropogenic origin, scale and pace of climate change remain subject to extensively propagated denial and untruths.

Figure 6. (A) Extreme weather events around the world 1980-2018,
including earthquakes, storms, floods, droughts. Munich Re-insurance.
Figure 6. (B) A satellite infrared image of South America fires (red dots) during July and August, 2019, NASA.
An uncharted climate territory

Whereas strict analogies between Quaternary and Anthropocene climate developments are not possible, elements of the glacial-interglacial history are relevant for an understanding of current and future climate events. The rise of total greenhouse gas (GHG), expressed as CO₂-equivalents, to 496 ppm CO₂-e (Figure 1), within less than a century represents an extreme atmospheric event. It raised GHG concentrations from Holocene levels to the range of the Miocene (34–23 Ma) when CO₂ level was between 300 and 530 ppm. As the glacial sheets disintegrate, cold ice-melt water flowing into the ocean ensue in large cold water pools, a pattern recorded following peak interglacial phases over the last 450,000 years, currently manifested by the growth of cold regions in north Atlantic Ocean south of Greenland and in the Southern Ocean fringing Antarctica (Figure 7).

Warming of +3°C to +4°C above pre-industrial levels, leading to enhanced ice-sheet melt, would raise sea levels by at least 2 to 5 meters toward the end of the century and, delayed by hysteresis, likely by 25 meters in the longer term. Golledge et al. (2019) show meltwater from Greenland will lead to substantial slowing of the Atlantic overturning circulation, while meltwater from Antarctica will trap warm water below the sea surface, increasing Antarctic ice loss. Whereas the effect of low-density ice melt water on the surrounding oceans is generally not included in many models, depending on amplifying feedbacks, prolonged Greenland and Antarctic melting and consequent cooling of surrounding ocean sectors as well as penetration of freezing air masses through weakened polar boundaries may have profound effect on future climate change trajectories (Figure 8).

Figure 7. (A) Global warming map (NASA 2018). Note the cool ocean regions south of Greenland and 
along  the Antarctic. Credits: Scientific Visualization Studio/Goddard Space Flight Center; 
(B) 2012 Ocean temperatures around Antarctica (NASA 2012). Climate projections for 2100-2300 by the IPCC AR5 Synthesis Report, 2014 portray predominantly linear to curved models of greenhouse gas, global temperatures and sea level changes. These models however appear to take limited account of amplifying feedbacks from land and ocean and of the effects of cold ice-melt on the oceans. According to Steffen et al. (2018) “self-reinforcing feedbacks could push the Earth System toward a planetary threshold” and “would lead to a much higher global average temperature than any interglacial in the past 1.2 million years and to sea levels significantly higher than at any time in the Holocene”.

Amplifying feedbacks of global warming include:
  • The albedo-flip of melting sea ice and ice sheets and the increase of the water surface area and thereby sequestration of CO₂. Hudson (2011) estimates a rise in radiative forcing due to removal of Arctic summer sea ice as 0.7 W/m², a value close to the total of methane release since 1750.
  • Reduced ocean CO₂ intake due to lesser solubility of the gas with higher temperatures.
  • Vegetation desiccation and burning in some regions, and thereby released CO₂ and reduced evaporation and its cooling effect. This factor and the increase of precipitation in other regions lead to differential feedbacks from vegetation as the globe warms (Notaro et al. 2007).
  • An increase in wildfires, releasing greenhouse gases (Figure 6).
  • Release of methane from permafrost, bogs and sediments and other factors.
Linear temperature models appear to take limited account of the effects on the oceans of ice melt water derived from the large ice sheets, including the possibility of a significant stadial event such as already started in oceanic tracts fringing Greenland and Antarctica (Figure 7) and modeled by Hansen et al, (2016). In the shorter to medium term sea level rises would ensue from the Greenland ice sheet (6-7 meter sea level rise) and West Antarctic ice sheet melt (4.8 meter sea level rise). Referring to major past stadial events, including the 8200 years-old Laurentian melt and the 12.7-11.9 younger dryas event, a protracted breakdown of parts of the Antarctic ice sheet could result in major sea level rise and extensive cooling of southern latitudes and beyond, parallel with warming of tropical and mid-latitudes (Figure 8) (Hansen et al. 2016). The temperature contrast between polar-derived cold fronts and tropical air masses is bound to lead to extreme weather events, echoed among other in Storms of my grandchildren (Hansen, 2010).

Figure 8. (A) Model Surface-air temperature (°C) for 2096 relative to 1880–1920 (Hansen et al. 2016).
The projection betrays major cooling of the North Atlantic Ocean, cooling of the circum-Antarctic Ocean
and further warming in the tropics, subtropics and the interior of continents; (B) Modeled surface-air
temperatures (°C) to 2300 AD relative to 1880–1920 for several ice melt rate scenarios, displaying a stadial cooling event at a time dependent on the ice melt doubling time (Hansen et al., 2016). Courtesy Prof James Hansen;.
Within and beyond 2100-2300 projections (Figure 8.A, B) lies an uncharted climate territory, where continuing melting of the Antarctic ice sheet, further cooling of neighboring sectors of the oceans and climate contrasts with GHG-induced warming of land areas (Figure 8.A), ensue in chaotic climate disruptions (Figure 8.B). Given the thousands to tens of thousands years longevity of atmospheric greenhouse gases (Solomon et al., 2009; Eby et al 2009), the onset of the next ice age is likely to be delayed on the scale of tens of thousands of years (Berger and Loutre, 2002) through an exceptionally long interglacial period (Figure 9).

These authors state: ‘The present day CO₂ concentration (now >410 ppm) is already well above typical interglacial values of ~290 ppmv. This study models increases to up to 750 ppmv over the next 200 years, returning to natural levels by 1000 years. The results suggest that, under very small insolation variations, there is a threshold value of CO₂ above which the Greenland Ice Sheet disappears. The climate system may take 50,000 years to assimilate the impacts of human activities during the early third millennium. In this case, an “irreversible greenhouse effect” could become the most likely future climate. If the Greenland and west Antarctic Ice Sheets disappear completely, then today’s “Anthropocene” may only be a transition between the Quaternary and the next geological period.’

Figure 9. Simulated Northern Hemisphere ice volume (increasing downward) for the period 200,000 years BP to 130,000 years in the future, modified after a part of Berger and Loutre 2002. Time is negative in the past and positive in the future. For the future, three CO2 scenarios were used: last glacial-interglacial values (solid line), a human-induced concentration of 750 ppm (dashed line), and a constant concentration of 210 ppm inducing a return to a glacial state (dotted line). As conveyed by leading scientists “Climate change is now reaching the end-game, where very soon humanity must choose between taking unprecedented action or accepting that it has been left too late and bear the consequences” (Prof. Hans Joachim Schellnhuber) …“We’ve reached a point where we have a crisis, an emergency, but people don’t know that ... There’s a big gap between what’s understood about global warming by the scientific community and what is known by the public and policymakers” (James Hansen).

Climate scientists find themselves in a quandary similar to medical doctors, committed to help the ill, yet need to communicate grave diagnoses. How do scientists tell people that the current spate of extreme weather events, including cyclones, devastating islands from the Caribbean to the Philippine, floods devastating coastal regions and river valleys from Mozambique to Kerala, Pakistan and Townsville, and fires burning extensive tracts of the living world, can only intensify in a rapidly warming world? How do scientists tell the people that their children are growing into a world where survival under a mean temperature higher than +2 degrees Celsius (above pre-industrial temperature) is likely to be painful and, in some parts of the world, impossible, let alone under +4 degrees Celsius projected by the IPCC?

Summary and conclusions
  1. The current growth rate of atmospheric greenhouse gas is the fastest recorded for the last 55 million years.
  2. By the mid-21st century, at the current CO₂ rise rates of 2 to 3 ppm/year, a CO₂-e level of >750 ppm is likely to transcend the climate tipping points indicated by Lenton et al. 2008 and Schellnhuber 2009.
  3. The current extreme rise rates of GHG (2.86 ppm CO₂/year) and temperature (0.15-0.20°C per decade since 1975) raise doubt with regard to linear future climate projections.
  4. Global greenhouse gases have reached a level exceeding the stability threshold of the Greenland and Antarctic ice sheets, which are melting at an accelerated rate.
  5. Allowing for the transient albedo-enhancing effects of sulphur dioxide and other aerosols, mean global temperature has reached approximately 2.0 degrees Celsius above per-industrial temperatures.
  6. Due to hysteresis the large ice sheets would outlast their melting temperatures.
  7. Land areas would be markedly reduced due to a rise to Miocene-like sea levels of approximately 40±15 meters above pre-industrial levels.
  8. Cold ice melt water flowing from the ice sheets into the oceans at an accelerated rate is reducing temperatures in large tracts in the North Atlantic and circum-Antarctic.
  9. Strong temperature contrasts between cold polar-derived and warm tropical air and water masses are likely to result in extreme weather events, retarding habitats and agriculture over coastal regions and other parts of the world.
  10. In the wake of partial melting of the large ice sheets, the Earth climate zones would continue to shift polar-ward, expanding tropical to super-tropical regions such as existed in the Miocene (5.3-23 million years ago) and reducing temperate climate zones and polar ice sheets.
  11. Current greenhouse gas forcing and global mean temperature are approaching Miocene Optimum-like composition, bar the hysteresis effects of reduced ice sheets (Figure 4.A).
  12. The effect of high atmospheric greenhouse gas levels would be for the next ice age to be delayed on a scale of tens of thousands of years, during which chaotic tropical to hyperthermal conditions would persist until solar radiation and atmospheric CO₂ subsided below ~300 ppm.
  13. Humans will survive in relatively favorable parts of Earth, such as sub-polar regions and sheltered mountain valleys, where gathering of flora and hunting of remaining fauna may be possible.

A Postscript

The author, while suggesting the projections made in this paper are consistent with the best climate science with which he is aware, sincerely hopes the implications of these projections would not eventuate.


[Author: Sam Carana] [Category: Andrew Glikson, change, climate, feedbacks, forcing, global, greenhouse gas, rise, temperature, warming]

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[l] at 9/27/19 9:14am

As illustrated by above map, Arctic heating is accelerating, with temperatures showing up in the Arctic that are up to 4.41°C hotter than the average global temperature during 1880-1920.

The image below shows two plots. On the left-hand side is the temperature plot associated with above map, had a monthly mean been selected. To smooth the data, a 4-year running mean was chosen, and the plot on the right-hand side shows the associated global mean anomalies. Note that, due to this smoothing, only data from 1882 to August 2017 are displayed in the plot of the right-hand side.


It is appropriate to adjust the data by 0.5°C, as follows:
  1. An adjustment of 0.3°C to reflect a pre-industrial baseline (heating occurred due to people's emissions before 1880-1920);
  2. An adjustment of 0.1°C to reflect air temperatures over oceans (as opposed to sea surface temperatures);
  3. An adjustment of 0.1°C to better include polar temperatures (the top and bottom of the image at the top shows large polar areas that should not be excluded, the more so since the Arctic has the highest temperature anomalies).
The image below shows both adjusted and unadjusted data as dark blue lines, with a light-blue polynomial trend added over the adjusted data.

Such a trend can further smooth out seasonal differences and El Niño/La Niña variability.

Such a trend can also show the potential for further temperature rise in the near future, which can constitute an important warning.

This is particularly important as the trend shows that we could be crossing the 2°C guardrail this year, i.e. the threshold that was too dangerous to be crossed.

What is the danger? Arctic heating is accelerating, as the image at the top shows, and this could make global temperatures skyrocket in a matter of years. Where Arctic sea ice disappears, hot water emerges due to albedo changes and loss of the buffer that has until now been consuming heat as part of the melting process. This is illustrated by the image below showing the sea surface temperature difference from 1961-1990 in the Arctic at latitudes 60°N - 90°N on August 23, 2019.


Disappearance of Arctic sea ice comes with numerous feedbacks that further speed up the heating, as described in the recent post Arctic Sea Ice Gone By September 2019?. Heatwaves can strongly heat up the water that gets carried by rivers into the Arctic Ocean. As the image below shows, the water was as hot as 10.7°C or 51.3°F at green circle on August 20, 2019, i.e. 9.4°C or 16.9°F hotter than 1981-2011.


As the Arctic is heating up faster than the rest of the world, the Jet Stream gets more and more distorted. A cyclone is forecast over the Arctic Ocean for August 24, 2019, pulling hot air over the Arctic Ocean, resulting in temperatures at the green circle as high as 10.4°C or 50.6°F at 1000 hPa and 7.4°C or 45.2°F at surface level, as the image below shows.


The image below illustrates the distortion of the Jet Stream, moving over the Arctic Ocean on August 24, 2019.


Such a cyclone can pull huge amounts of hot air over the Arctic Ocean, while it can also devastate the sea ice with the destructive power of winds, rain and hail.


As above animation shows, Arctic sea ice is very thin and vulnerable at the moment. The cyclone also looks set to batter the sea ice at a time when huge amounts of ocean heat are entering the Arctic Ocean from the Atlantic and Pacific Oceans. More ocean heat looks set to be on the way. As the image below shows, sea surface temperatures around North America were as high as 33°C or 91.4°F on August 21, 2019.


The image below shows the worrying rise of Northern Hemisphere sea surface temperature anomalies from the 20th century average, with the added trend illustrating the danger that this rise will lead to Arctic sea ice collapse and large methane eruptions from the seafloor of the Arctic Ocean, further accelerating the temperature rise.

[ from an earlier post ] The image below shows the cyclone over the Arctic Ocean on August 26, 2019.


The image below shows a close-up of the sea ice just north of the North Pole, on August 26, 2019.


The situation is dire and calls for comprehensive and effective action, as described in the Climate Plan.


Links

• Climate Plan
https://arctic-news.blogspot.com/p/climateplan.html

• Arctic Sea Ice Gone By September 2019?
https://arctic-news.blogspot.com/2019/07/arctic-sea-ice-gone-by-september-2019.html

• July 2019 Hottest Month On Record
https://arctic-news.blogspot.com/2019/08/july-2019-hottest-month-on-record.html


[Author: Sam Carana] [Category: anomaly, Arctic, cyclone, ocean, rise, sea surface, temperature]

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[l] at 9/27/19 8:37am

The IPCC has issued another special report: The Ocean and Cryosphere in a Changing Climate.

How much carbon is there in the Arctic?

[ click on images to enlarge ] How much carbon is present in the northern circumpolar permafrost region (map)?

According to the report, there is 1460 to 1600 billions of tons of carbon (GtC) present in the soil on land. The report also mentions that there is additional carbon present on shallow Arctic sea shelves, but the report doesn't add figures.

Natalia Shakhova et al. once estimated the accumulated methane potential for the Eastern Siberian Arctic Shelf alone to be about 500 Gt of organic carbon, with an additional amount in hydrates of about 1000 Gt and a further amount of methane in free gas of about 700 Gt. Back in 2008, Natalia Shakhova et al. considered release of up to 50 Gt of predicted amount of hydrate storage as highly possible for abrupt release at any time.

How much of these vast amounts could be released to the atmosphere? 

The IPCC report projects permafrost near the surface (top 3–4 m) to decrease in area by up to 89% by 2100 under a high emissions scenario (RCP8.5), leading to cumulative release of tens to hundreds of billions of tons of carbon in the form of carbon dioxide and methane to the atmosphere by 2100.

The report fails to warn that, as the Arctic Ocean keeps heating up, huge seafloor methane eruptions could be triggered, and that this could happen within years, as discussed at the extinction page. Abrupt release of 10 Gt of methane would triple the amount of methane in the atmosphere, resulting in huge heating, while it would also trigger the clouds feedback tipping point to be crossed that in itself could push global temperatures up by 8°C within a few years, as earlier discussed in this post and this post.

Sea ice

The report notes that between 1979 and 2018, the areal proportion of multi-year Arctic sea ice at least five years old has declined by approximately 90%. The report refers to a study by Pistone that concludes that the additional heating due to complete Arctic sea ice loss would hasten global warming by an estimated 25 years.

The image below shows the difference in Arctic sea ice extent between the years, from an earlier post.


The report concludes that Antarctic sea ice extent overall has had no statistically significant trend. At the same time, the report notes that the Southern Ocean's share of the total heat gain in the upper 2000 m global ocean increased to 45–62% between 2005 and 2017. Below is an image illustrating the difference in Antarctic sea ice extent between the years.


The image below shows how much global sea ice extent has decreased over the past few years.

Sea ice decline makes that less sunlight gets reflected back into space and more heat gets absorbed by the ocean. The report also mentions latent heat changes and increased water vapor and increased cloudiness over the Arctic Ocean. Furthermore, as the temperature difference between the North Pole and the Equator narrows, the Jet Stream changes, which makes it more likely that a large influx of hot, salty water can enter the Arctic Ocean.


The situation is dire and calls for comprehensive and effective action, as described in the Climate Plan.


Links

• Climate Plan
https://arctic-news.blogspot.com/p/climateplan.html

• IPCC special report, The Ocean and Cryosphere in a Changing Climate
https://www.ipcc.ch/srocc/home

• Extinction
https://arctic-news.blogspot.com/p/extinction.html

• Most Important Message Everhttps://arctic-news.blogspot.com/2019/07/most-important-message-ever.html

• When Will We Die?https://arctic-news.blogspot.com/2019/06/when-will-we-die.html

• Critical Tipping Point Crossed In July 2019https://arctic-news.blogspot.com/2019/09/critical-tipping-point-crossed-in-july-2019.html

• Radiative Heating of an Ice‐Free Arctic Ocean, by Kristina Pistone et al.
https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019GL082914

• IPCC Report Climate Change and Land
https://arctic-news.blogspot.com/2019/08/ipcc-report-climate-change-and-land.html

• IPCC keeps feeding the addication
https://arctic-news.blogspot.com/2018/10/ipcc-keeps-feeding-the-addiction.html

• IPCC seeks to downplay global warming
https://arctic-news.blogspot.com/2018/02/ipcc-seeks-to-downplay-global-warming.html

• Just do NOT tell them the monster exists
https://arctic-news.blogspot.com/2013/10/just-do-not-tell-them-the-monster-exists.html




[Author: Sam Carana] [Category: albedo, Arctic, cryosphere, IPCC, methane, ocean, sea ice]

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[l] at 9/14/19 5:09pm
The changing face of planet Earth

Andrew Glikson
Earth and Climate scientist
Australian National University

12-8-2019

Preamble
The inhabitants of planet Earth are in the process of destroying the habitability of their world through the perpetration of the largest mass extinction of species since 66 million years ago, when a large asteroid impacted Earth, and 55 million years since the Paleocene-Eocene Thermal Maximum (PETM) reaching 5–8°C. The late Holocene-Anthropocene climate change represents an unprecedented event, triggering a fast shift in climate zones and a series of extreme weather events, with consequences for much of nature and civilization. The changes are manifest where green forests are blackened by fire, droughts are turning grassy planes to brown semi-deserts, brilliant white snow and ice caps are melting into pale blue water and clear blue skies turn grey due to aerosols and jet contrails, most particularly in the northern hemisphere. Unless effective efforts are undertaken at CO₂ drawdown, the consequence would include demise of much of nature and a collapse of human civilization.

1. The scorched Earth

The transfer of hundreds of billions of tonnes of carbon from the Earth crust, the residues of ancient biospheres, to the atmosphere and oceans, condemning the bulk of life through the most extreme shift in the composition of the atmosphere and ocean Earth has experienced since 55 million years ago, with changes taking place in front of our eyes. Since the industrial revolution, about 375 billion tonnes of carbon (or 1,374 billion tonnes CO₂) have been emitted by humans into the atmosphere. The consequences are everywhere, from mega-droughts, to heat waves, fires, storms and floods. With atmospheric CO₂-equivalent rising above 500 ppm and mean temperatures by more than 1.5°C (Figure 1) look no further than the shift in climate zones, displayed for example on maps of the expanding wet tropical zones, drying sub-tropical latitudes and polar-ward migration of temperate climate zone. The ice sheets and sea ice are melting, huge fires overtake Siberia, the Sahara is shifting northward, large parts of southern Europe are suffering from droughts, heat waves and fires, the Kalahari Desert dunes are shifting and much of southern Australia is affected by warming and draughts. This is hardly compensated by a minor increase in precipitation and greening such as at the southern fringes of the Sahara Desert and parts of northern Australia.

Induced by anthropogenic carbon emissions reaching 37.1 billion tonnes CO₂ in 2018 and their amplifying feedbacks from land and oceans and, ranging from 16.5 tonnes CO₂ per capita per year from the US to 35.5 tonnes CO₂ per capita per year from Saudi Arabia and 44  tonnes CO₂  per capita per year from Australia, the inexorable link between these emissions and the unfolding disaster is hardly mentioned by mainstream political classes and the media.

Figure 1 (A) Growth of CO₂-equivalent level and the annual greenhouse gas Index (AGGI¹). Measurements of CO₂ to
the 1950s are from (Keeling et al., 1958) and air trapped in ice and snow above glaciers. Pre-1978 changes are based
on ongoing measurements of all greenhouse gases. Equivalent CO₂ amounts (in ppm) are derived from the relationship
between CO₂ concentrations and radiative forcing from all long lived gases; (B) showing how much warmer each
month of the GISTEMP data is than the annual global mean. For July (2019) temperatures rose by about +1.5°C.
¹The AGGI index uses 1990 as a baseline year with a value of 1. The index increased every year since 1979.
2. Migrating climate zones

As the globe warms, to date by a mean of near ~1.5 °C, or ~2.0°C when the masking effects of sulphur dioxide and other aerosols are considered, and by a mean of ~2.3°C in the polar regions, the expansion of warm tropical latitudes and the pole-ward migration of subtropical and temperate climate zones (Figure 2) ensue in large scale droughts such as parts of inland Australia and southern Africa. A similar trend is taking place in the northern hemisphere where the Sahara desert is expanding northward, with consequent heat waves across the Mediterranean and Europe.

In southern Africa “Widespread shifts in climate regimes are projected, of which the southern and eastern expansion of the hot desert and hot steppe zones is most prominent. From occupying 33.1 and 19.4 % of southern Africa under present-day climate, respectively, these regions are projected to occupy between 47.3 and 59.7 % (hot desert zone) and 24.9 and 29.9 % (hot steppe zone) of the region in a future world where the mean global temperature has increased by ~3°C.

Closely linked to the migration of climate zones is the southward drift of Antarctic- sourced cold moist fronts which sustain seasonal rain in south-west and southern Australia. A feedback loop has developed where deforestation and decline in vegetation in southern parts of the continent result in the rise of thermal plumes of dry air masses that deflect the western moist fronts further to the southeast.

Figure 2. Köppen-Geiger global Climate zones classification map
Since 1979 the planet’s tropics have been expanding pole-ward by 56 km to 111 km per decade in both hemispheres, leading one commentator to call this Earth’s bulging waistline. Future climate projections suggest this expansion is likely to continue, driven largely by human activities – most notably emissions of greenhouse gases and black carbon, as well as warming in the lower atmosphere and the oceans.”

An analysis of the origin of Australian droughts suggests, according to both observations and climate models, that at least part of this decline is associated with changes in large-scale atmospheric circulation, including shrinking polar ice and a pole-ward movement of polar-originated westerly wind spirals, as well as increasing atmospheric surface pressure and droughts over parts of southern Australia (Figure 3). Simulations of future climate with this model suggest amplified winter drying over most parts of southern Australia in the coming decades in response to changes in radiative forcing. The drying is most pronounced over southwest Australia, with total reductions in austral autumn and winter precipitation of approximately 40% by the late twenty-first century. Thus rainfall in southwestern Australia has declined sharply from about 1965 onward, concomitant with the sharp rise of global temperatures.

Figure 3 (A) Bureau of Meteorology (BOM) drought map, showing rainfall levels for the southern wet season from
April 1 to July 31 in 2019; (B) NASA satellite image displaying a southward deflection of Antarctic-sourced moist
cold fronts from southern Australia, a result of (1) southward migration of climate zones; (2) increasing aridity of
southern and southwestern Australia due to deforestation; (3) rising hot plumes from warming arid land.
3. Extreme weather events

The consequences of the migration of climate zones are compounded by changes in flow patterns of major river systems around the world, for example in southern an southeastern Asia, including the Indus, Ganges, Brahmaputra and Mekong river basins, the home and bread basket for more than a billion people. With warming, as snow cover declines in the mountainous source regions of rivers, river flows are enhanced, with ensuing floods, in particular during the Monsoon. For example, in 2010 approximately one-fifth of Pakistan's total land area was affected by floods (Figure 4A), directly affecting about 20 million people, with a death toll close to 2,000. And about 700 people in cyclone Isai in Mozambique (Figure 4B, C). Such changes in climate and geography are enhanced once sea level rise increases from the scale of tens of centimeters, as at present, to meters, as predicted to take place later this and next century.

An increasing frequency and intensity of cyclones constitute an inevitable consequence of rising temperatures over warm low pressure cell tracks in tropical oceans, already affecting large populations in the Caribbean and west Pacific island chains, encroaching into continental coastal zones, China, southeast USA, southeast Africa, India, northern Australia, the Pacific islands. According to Sobel et al. (2016) “We thus expect tropical cyclone intensities to increase with warming, both on average and at the high end of the scale, so that the strongest future storms will exceed the strength of any in the past”. Likewise increasing temperatures, heat waves and droughts, compounded by deforestation over continents, constitute an inevitable consequence of heat waves and droughts. A prime example is the Siberian forest fires (Figure 5B), covering an area larger than Denmark and contributing significantly to climate change. Since the beginning of the year a total of 13.1 million hectares has burned. Total losses from natural catastrophes on 2018 stated as US$160 billion.

Figure 4 (A) Pakistan flooding, shows the 2010 Indus River spanning well over 10 kilometers, completely filling
the river valley and spilling over onto nearby land. Floodwaters have created a lake almost as wide as the swollen
Indus that inundates Jhatpat; (B) Before-and-after satellite imagery of Mozambique showing massive flood
described as an "inland ocean" up to 30 miles wide following the landfall of Tropical Cyclone Idai, 2019. Figure 5 (A) Global fire zones, NASA. The Earth data fire map accumulates the locations of fires detected by
moderate-resolution imaging radiometer (MODIS) on board the Terra and Aqua satellites over a 10-day period.
Each colored dot indicates a location where MODIS detected at least one fire during the compositing period.
Color ranges from red where the fire count is low to yellow where number of fires is large; (B) An ecological
catastrophe in Russia: wildfires have created over 4 million square km smoke lid over central northern Asia.
Big Siberian cities are covered with toxic haze that had already reached Urals.
4. Shrinking Polar ice sheets

Last but not least, major changes in the Polar Regions are driving climate events in the rest of the globe. According to NOAA Arctic surface air temperatures continued to warm at twice the rate of the rest of the globe, leading to major thaw at the fringes of the Arctic (Figure 6A) and a loss of 95 percent of its oldest ice over the past three decades. Arctic air temperatures during 2014-18 since 1900 have exceeded all previous records and are driving broad changes in the environmental system both within the Arctic as well as through the weakening of the jet stream which separates the Arctic from warmer climate zones. The recent freezing storms in North America represent penetration of cold air masses through an increasingly undulating jet stream barrier, as well as allowing warm air masses to move northward, further warming the Arctic and driving further ice melting (Figure 6B).

According to Rignot et al. (2011) in 2006 the Greenland and Antarctic ice sheets experienced a combined mass loss of 475 ± 158 billion tons of ice per year. IPCC models of future climate change contain a number of departures from the paleoclimate evidence, including the major role of feedbacks from land and water, estimates of future ice melt, sea level rise rates, methane release rates, the role of fires in enhancing atmospheric CO₂, and the already observed onset of transient freeze events consequent on the flow of ice melt water into the oceans. Ice mass loss would raise sea level on the scale of meters and eventually tens of meters (Hansen et al. 2016). The development of large cold water pools south and east of Greenland (Rahmstorf et al. 2015) and at the fringe of West Antarctica, signify early stages in the development of a North Atlantic freeze, consistent with the decline in the Atlantic Meridional Ocean Circulation (AMOC). As the Earth warms the increase in temperature contrasts across the globe, in particular between warming continental regions and cooling ocean regions, leads to storminess and extreme weather events, which need to be taken into account when planning adaptation measures, including preparation of coastal defenses, construction of channel and pipelines from heavy precipitation zones to drought zones.

Figure 6 (A) Thawing at the fringes of Siberia and Canada. Scientists say 2019 could be another annus
horribilis for the Arctic with record temperatures already registered in Greenland—a giant melting ice
sheet that threatens to submerge the world's coastal areas one day; (B) Weakening and increasing undulation
of the polar vortex , allowing penetration of cold fronts southward and of warm air masses northward. Figure 7 (A) Surface air temperature (°C) change in 2055–2060 relative to 1880–1920 according to.
A1B model + modified forcings and ice melt to 1 meter sea level rise; (B) Surface-air temperature
change in 2096 relative to 1880–1920 according to IPCC model AIB adding Ice melt with 10-year
doubling of ice melt leading to +5 meters sea level rise; (C) Surface air temperature (°C) relative to
1880–1920 for several scenarios taking added ice melt water into account (Hansen et al. 2016)
Postscript

None of the evidence and projections summarized above appears to form a priority consideration on the part of those in power—in parliaments, in corporations, among the wealthy elites and vested interests. Having to all intents and purposes given up on the habitability of large parts of the Earth and on the survival of numerous species and future generations—their actions and inactions constitute the ultimate crime against life on Earth.


Andrew Glikson

Dr Andrew Glikson Earth and climate scientist
Australian National University
Canberra, Australian Territory, Australia geospec@iinet.net.au
Books : The Archaean: Geological and Geochemical Windows into the Early Earth
http://www.springer.com/gp/ book/9783319079073 The Asteroid Impact Connection of Planetary Evolution http://www.springer.com/gp/ book/9789400763272 Asteroids Impacts, Crustal Evolution and Related Mineral Systems with Special Reference to Australia http://www.springer.com/us/ book/9783319745442  Climate, Fire and Human Evolution: The Deep Time Dimensions of the Anthropocene http://www.springer.com/gp/ book/9783319225111 The Plutocene: Blueprints for a Post-Anthropocene Greenhouse Earth http://www.springer.com/gp/ book/9783319572369 Evolution of the Atmosphere, Fire and the Anthropocene Climate Event Horizon http://www.springer.com/gp/ book/9789400773318  From Stars to Brains: Milestones in the Planetary Evolution of Life and Intelligence https://www.springer.com/us/ book/9783030106027
From Stars to Brains: Milestones in the Planetary Evolution of Life and Intelligence
The Plutocene: Blueprints for a Post-Anthropocene Greenhouse Earth
Added below is a video with an August 6, 2019, interview of Andrew Glikson by Guy McPherson and Kevin Hester, as edited by Tim Bob.



[Author: Sam Carana] [Category: Andrew Glikson, extreme weather, PETM]

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[l] at 9/14/19 4:36pm
The IPCC has just issued a special report Climate Change and Land, on climate change, desertification, land degradation, sustainable land management, food security, and greenhouse gas fluxes in terrestrial ecosystems. In its new report 'Climate Change and Land', the IPCC finds that vegan is the best diet to reduce emissions. Sadly, it is yet another missed opportunity to show some integrity.

[ click on image to enlarge ] Indeed, little or nothing will change as long as the IPCC keeps downplaying the dire situation we're in.

As an example, the IPCC Report uses a very low value of 28 as Global Warming Potential (GWP) for methane, which is totally inappropriate and unacceptable given the rapidity at which the biosphere is deteriorating, given the accelerating pace at which extreme weather events are striking the land all around the world, and given the grim prospects for people worldwide in the absence of rapid and radical change.

The report finds that agriculture, forestry and other land use activities accounted for around 13% of carbon dioxide, 44% of methane, and 82% of nitrous oxide emissions from human activities globally during 2007-2016, representing 23% of total net anthropogenic emissions of greenhouse gases. If emissions associated with pre- and post-production activities in the global food system are included, the emissions could be as high as 37% of total net anthropogenic greenhouse gas emissions.

The Report adds an image showing that annual methane emissions from agriculture had reached some 4Gt CO₂eq in 2016. The IPCC notes that this 4Gt for methane's CO₂-eq is based on a GWP for methane of 28 over 100 years and without climate-carbon feedbacks, taken from its Fifth Assessment Report (AR5), published in 2014.

As said, the Report calculates that net greenhouse gas emissions from agriculture, forestry, and other land use were 23% of people's 2007-2016 emissions when using a GWP of 28 for methane. When using a GWP of 150, that share rises to 31%, as illustrated by the image on the right.

Instead of calculating methane's GWP over 100 years, a very short horizon is appropriate. Moreover, research published in 2016 and 2018 had already found methane to be more potent than IPCC's GWP for methane in AR5, as discussed in a recent post.

When using an appropriate GWP, the percentage of greenhouse gases coming from agriculture (in particular livestock products) increases dramatically, thus rightly highlighting the urgency for governments to act, e.g. by implementing local feebates, such as fees on livestock products and nitrogen fertilizers with revenues used to support soil supplements containing biochar, as recommended in a recent post.


Furthermore, the IPCC should have pointed the finger at the cartel of looters comprising fuel, meat, chemical and pharmaceutical industries and fuel-powered vehicle manufacturers and utilities that finances corrupt politicians and that goes hand in glove with a military-industrial complex that feeds on manufacturing conflict over resources that are the very cause of the wrath of pollution.

The situation is dire and calls for comprehensive and effective action, as described in the Climate Plan.


Links

• IPCC special report Climate Change and Land
https://www.ipcc.ch/report/srccl

• IPCC special report Global Warming of 1.5°C
https://report.ipcc.ch/sr15/

• IPCC keeps feeding the addiction
https://arctic-news.blogspot.com/2018/10/ipcc-keeps-feeding-the-addiction.html

• How much warming have humans caused?
https://arctic-news.blogspot.com/2016/05/how-much-warming-have-humans-caused.html

• Most Important Message Ever
https://arctic-news.blogspot.com/2019/07/most-important-message-ever.html

• Feedbacks
https://arctic-news.blogspot.com/p/feedbacks.html

• Extinction
https://arctic-news.blogspot.com/p/extinction.html

• Most Important Message Ever
https://arctic-news.blogspot.com/2019/07/most-important-message-ever.html

• How much warmer is it now?
https://arctic-news.blogspot.com/2018/04/how-much-warmer-is-it-now.html

• A rise of 18°C or 32.4°F by 2026?
https://arctic-news.blogspot.com/2019/02/a-rise-of-18c-or-324f-by-2026.html

• Climate Plan (page)
https://arctic-news.blogspot.com/p/climateplan.html

• Climate Plan (post)
https://arctic-news.blogspot.com/2019/06/climate-plan.html

• Olivine weathering to capture CO2 and counter climate change
https://arctic-news.blogspot.com/2016/07/olivine-weathering-to-capture-co2-and-counter-climate-change.html

Discussions

• Biochar
https://www.facebook.com/groups/biochar

• Geoengineering
https://www.facebook.com/groups/geoengineering

• Climate Alert
https://www.facebook.com/groups/climatealert

• Arctic News
https://www.facebook.com/groups/arcticnews

• Vegan Organic Food
https://www.facebook.com/groups/veganorganicfood

• Climate Plan
https://www.facebook.com/groups/climateplan



[Author: Sam Carana] [Category: AR5, biochar, climate change, diet, food, GWP, IPCC, methane, organic, vegan]

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[l] at 9/14/19 4:03pm

The July 2019 temperature was on a par with, and possibly marginally higher than, that of July 2016, according to a World Meteorological Organization (WMO) news release pointing an image by the Copernicus Climate Change Programme that is used as the background for above image.

Previously, July 2016 was the hottest July on record with a global land and ocean temperature of 16.67°C (62.01°F), or 3.25°C above the pre-industrial temperature of 13.42°C (56.16°F) and surpassing the record set before that, in July 2015.

The July 2019 Surface Temperature was 16.7°C in real temperatures (as opposed to anomalies), as illustrated by the image on the right, supplied by James Hansen and constructed using Dr. Phil Jones climatology and GISS 250 km smoothing of anomalies.

The image also shows, James Hansen adds, that the monthly mean of the daily mean (not daily maximum) exceeded 35°C (95°F) in parts of North Africa and the Middle East.

The month July typically is the hottest month of the year. July 2019 was 2.34°C (or 4.21°F) hotter than the 1980-2015 annual global mean, and July 2019 was the hottest July on record, making it the hottest month on record to date.

According to NASA data, July 2016 was 2.26°C hotter than the 1980-2015 annual global mean, and August 2016 was actually the previously hottest month on record with 2.31°C above the 1980-2015 annual mean, so August 2019 could be even hotter, which is quite remarkable given that we're currently in an El Niño-neutral period.

There's a spread of more than 3°C between the coldest and hottest monthly temperatures, in line with the seasonal cycle. Since the land/sea ratio is larger on the Northern Hemisphere and land heats up faster than oceans, July typically is the hottest month of the year, so the annual mean temperature for the year 2019 will be somewhat lower than the temperature for July 2019.


Above image takes another perspective, showing NASA Land and Ocean Temperature Index (LOTI) data that are adjusted 0.78° to reflect a 1750 baseline (as opposed to NASA's default 1951-1980 baseline), to reflect ocean air temperatures (as opposed to sea surface temperatures) and higher polar anomaly (to better reflect absent data).

Two trends are added, based on the adjusted data, as described in an earlier analysis. The blue long-term trend is based on 1880-July 2019 data and points at a 3°C (or 5.4°F) rise by 2026. The red short-term trend is based on 2012-July 2019 data, to better illustrate El Niño/La Niña variability and the danger that large methane eruptions from the seafloor of the Arctic Ocean could result in near-term human extinction.

NASA's LOTI anomaly of 0.93°C above 1951-1980 for July 2019 becomes 1.71°C above pre-industrial when adjusted as described above. The trends also show that it could be 1.85°C above pre-industrial, in line with the earlier analysis that already pointed at a potential mean temperature for 2019 of 15.27°C, or 1.85°C above pre-industrial. Depending on what will happen in the Arctic and on further variables such as the strength of El Niño over the remainder of the year, 2019 could even cross the 2°C guardrail that politicians at the Paris Agreement pledged would not be crossed.


Above image shows the worrying rise of Northern Hemisphere sea surface temperature anomalies from the 20th century average, with the added trend illustrating the danger that this rise will lead to Arctic sea ice collapse and large methane eruptions from the seafloor of the Arctic Ocean, further accelerating the temperature rise.

Unbearable heat

As temperatures keep rising, there are places on the northern hemisphere where the July heat is becoming ever harder to bear.

The image on the right shows that on July 29, 2019, it felt like it was as hot as 57.2°C or 135°F in China (in the area marked by the green circle).

How could it get this hot? As the image underneath on the right shows, the temperature in that area was 35.1°C or 95.1°F (at the right circle), while it was much hotter at some places elsewhere in China, e.g. it was 41.5°C or 106.6°F at the left circle on July 29, 2019.

What made the weather so hard to bear was a combination of high temperature and high relative humidity, which was 81% in the area at the circle on the right at the time.

The jet stream is becoming ever more deformed as the Arctic heats up faster than the rest of the world. On July 29, 2019, the jet stream was all over the place, with a strong presence north of the circle, which made warm, moist air from the south move over China.

Since the Arctic continues to heat up faster than the rest of the world, such situations are likely to become more common. As noted in an earlier post, cyclones can increase humidity, making conditions worse. New research has meanwhile emerged pointing at the increasing risk associated with the combination of cyclones and heatwaves.

Wet Bulb Temperature

The temperature in that area of 35.1°C, at 81% relative humidity and a pressure level of 1004 hPa, translates into a wet bulb temperature of 32.11°C.

Had the temperature remained at 35.1°C, but had relative humidity kept rising to 100%, i.e. rainfall, the wet bulb temperature threshold of 35°C would have been exceeded (35.01°C). Alternatively, had relative humidity remained at 81%, but had the temperature kept rising to 38.2°C, the wet bulb temperature threshold of 35°C would equally have been exceeded (35.07°C), showing how dangerous the situation is. A wet bulb temperature of 35°C can be lethal, as the human body will be unable to lose heat, even when the wind is strong and no matter how much one drinks or sweats.

The situation is dire and calls for comprehensive and effective action, as described in the Climate Plan.


Links

• Another exceptional month for global average temperatures, Copernicus Climate Change Service, ECMWF
https://climate.copernicus.eu/another-exceptional-month-global-average-temperatures

• July matched, and maybe broke, the record for the hottest month since analysis began
https://public.wmo.int/en/media/news/july-matched-and-maybe-broke-record-hottest-month-analysis-began

• NOAA Global Climate Report - July 2016
https://www.ncdc.noaa.gov/sotc/global/201607

• July 2019 Global Temperature Update, by James Hansen
http://www.columbia.edu/~mhs119/Temperature/Emails/July2019.pdf

• An emerging tropical cyclone–deadly heat compound hazard, by Tom Matthews et al. (2019)
https://www.nature.com/articles/s41558-019-0525-6

• Most Important Message Ever
https://arctic-news.blogspot.com/2019/07/most-important-message-ever.html

• Temperature
https://arctic-news.blogspot.com/p/temperature.html

• How Much Warming Have Humans Caused?
https://arctic-news.blogspot.com/2016/05/how-much-warming-have-humans-caused.html

• It could be unbearably hot in many places within a few years time
https://arctic-news.blogspot.com/2016/07/it-could-be-unbearably-hot-in-many-places-within-a-few-years-time.html

• Peaks Matter
https://arctic-news.blogspot.com/2018/08/peaks-matter.html

• Extinction Alert
https://arctic-news.blogspot.com/2019/02/extinction-alert.html

• Climate Plan
https://arctic-news.blogspot.com/p/climateplan.html


[Author: Sam Carana] [Category: Arctic, jet stream, ocean, relative humidity, rise, SST, temperature, wet bulb]

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[l] at 9/14/19 3:30pm
Record low Arctic sea ice extent for the time of year


Arctic sea ice minimum extent typically occurs about half September. In 2012, minimum extent was reached on September 17, 2012, when extent was 3.387 million km².

On July 28, 2019, Arctic sea ice extent was 6.576 million km². How much extent do you think there will be by September 17, 2019? From July 28, 2019, to September 17, 2019, that's a period of 52 days during which a lot of melting can occur. Could there be a Blue Ocean Event in 2019, with virtually all sea ice disappearing in the Arctic?

Consider this. Extent was 6.926 million km² on September 17, 1989. Extent was 3.387 million km² on September 17, 2012, so 3.539 million km² had disappeared in 23 years. Over those years, more ice extent disappeared than what was left on September 17, 2012.

The question is how much sea ice extent will be left when it will reach its minimum this year, i.e. in September 2019. The red dashed line on the image at the top continues the path of the recent fall in sea ice extent, pointing at zero Arctic sea ice extent in September 2019. Progress is followed at this post.

Zero Arctic sea ice in 2019

Zero Arctic sea ice in 2019 sounds alarming, and there is good reason to be alarmed.


Above map shows temperatures on Greenland on July 31, 2019, with temperatures at one location as high as 23.2°C or 73.8°F and at another location - in the north - as high as 14.2°C or 57.6°F.

The map on the right shows sea surface temperature anomalies compared to 1961-1990 as on July 29, 2019. Note the high anomalies in the areas where the sea ice did disappear during the past few months. The reason for these high anomalies is that the buffer has disappeared that previously had kept consuming heat in the process of melting.

Where that buffer is gone, the heat has to go somewhere else, so it will be absorbed by the water and it will also speed up heating of the atmosphere over the Arctic.

Sea ice melting is accelerating for a number of reasons:
  • Ocean Heat - Much of the melting of the sea ice occurs from below and is caused by heat arriving in the Arctic Ocean from the Atlantic Ocean and the Pacific Ocean. 
  • Direct Sunlight - Hot air will melt the ice from above and this kind of melting can increase strongly due to changing wind patterns. 
  • Rivers - Heatwaves over land can extend over the Arctic Ocean and they also heat up river water flowing into the Arctic Ocean.
  • Fires - Changing wind patterns can also increase the intensity and duration of such heatwaves that can also come with fires resulting in huge amounts of greenhouse gas emissions, thus further speeding up the temperature rise, and also resulting in huge emissions of soot that, when settling on sea ice, speeds up melting (see images below). 
  • Numerous feedbacks will further speed up melting. Heating is changing the texture of the sea ice at the top and is making melt pools appear, both of which cause darkening of the surface. Some further feedbacks, i.e. storms and clouds are discussed below in more detail. 

Above combination image shows smoke from fires in Siberia getting pushed over the Laptev Sea on August 11, 2019, due to cyclonic winds over the Arctic Ocean. This was also discussed in an earlier post. The image below shows the situation on August 12, 2019.


The image below shows the situation on August 14, 2019.


In the video below, Paul Beckwith discusses the situation.


In the video below, Paul Beckwith discusses the heating impact of albedo loss due to Arctic sea ice loss, including the calculations in a recent paper.


As the Arctic is heating up faster than the rest of the world, it is also more strongly affected by the resulting extreme weather events, such as heatwaves, fires, strong winds, rain and hail storms, and such events can strongly speed up the melting of the sea ice.


All around Greenland, sea ice has now virtually disappeared. This is the more alarming considering that the thickest sea ice was once located north of Greenland. This indicates that the buffer is almost gone.

Why is disappearance of Arctic sea ice so important? Hand in hand with albedo loss as the sea ice disappears, there is loss of the buffer (feedbacks #1, #14 and more). As long as there is sea ice in the water, this sea ice will keep absorbing heat as it melts, so the temperature will not rise at the sea surface. The amount of energy absorbed by melting ice is as much as it takes to heat an equivalent mass of water from zero to 80°C.


Once the sea ice is gone, further heat must go elsewhere. This heat will raise the temperature of the water and will also make the atmosphere heat up faster.

Storms and Clouds

Storms: As temperatures in the Arctic are rising faster than at the Equator, the Jet Stream is changing, making it easier for warm air to enter the Arctic and for cold air to descend over continents that can thus become much colder than the oceans, and this stronger temperature difference fuels storms.

Clouds: More evaporation will occur as the sea ice disappears, thus further heating up the atmosphere (technically know as latent heat of vaporization).

In the video below, Paul Beckwith further discusses Arctic albedo change and clouds.



Disappearance of the sea ice causes more clouds to form over the Arctic. This on the one hand makes that more sunlight gets reflected back into space. On the other hand, this also make that less outward infrared radiation can escape into space. The net effect of more clouds is that they are likely cause further heating of the air over the Arctic Ocean (feedbacks #23 and #25).

More low-altitude clouds will reflect more sunlight back into space, and this occurs most during Summer when there is most sunshine over the Arctic. The image below, a forecast for August 17, 2019, shows rain over the Arctic. Indeed, more clouds in Summer can also mean rain, which can devastate sea ice, as discussed in an earlier post.


Regarding less outward radiation, the IPCC has long warned, e.g. in TAR, about a reduction in outgoing longwave radiation (OLR): "An increase in water vapour reduces the OLR only if it occurs at an altitude where the temperature is lower than the ground temperature, and the impact grows sharply as the temperature difference increases."

While reduction in OLR due to water vapor is occurring all year long, the impact is particularly felt in the Arctic in Winter when the air is much colder than the surface. In other words, less OLR makes Arctic sea ice thinner, especially in Winter.

The inflow of ocean heat into the Arctic Ocean can increase strongly as winds increase in intensity. Storms can push huge amounts of hot, salty water into the Arctic Ocean, as discussed earlier, such as in this post and this post. As also described at the extreme weather page, stronger storms in Winter will push more ocean heat from the Atlantic toward the Arctic Ocean, further contributing to Arctic sea ice thinning in Winter.

Seafloor Methane


[ The Buffer has gone, feedbacks #14 and #16 ]
As the buffer disappears that until now has consumed huge amounts of heat, the temperature of the water of the Arctic Ocean will rise even more rapidly, with the danger that further heat will reach methane hydrates at the seafloor of the Arctic Ocean, causing them to get destabilized and release huge amounts of methane (feedback #16).

Ominously, high methane levels were recorded at Barrow, Alaska, at the end of July 2019, as above image shows.


[ from an earlier post ] And ominously, a mean global methane level as high as 1902 ppb was recorded by the MetOp-1 satellite in the afternoon of July 31, 2019, as above image shows.

As the image on the right shows, mean global levels of methane (CH₄) have risen much faster than carbon dioxide (CO₂) and nitrous oxide (N₂O), in 2017 reaching, respectively, 257%, 146% and 122% their 1750 levels.

Temperature Rise

Huge releases of seafloor methane alone could make marine stratus clouds disappear, as described in an earlier post, and this clouds feedback could cause a further 8°C global temperature rise.

Indeed, a rapid temperature rise of as much as 18°C could result by the year 2026 due to a combination of elements, including albedo changes, loss of sulfate cooling, and methane released from destabilizing hydrates contained in sediments at the seafloor of oceans.

[ from an earlier post ]
Below is Malcolm Light's updated Extinction Diagram.

[ click on images to enlarge ] The situation is dire and calls for comprehensive and effective action, as described in the Climate Plan.


Link

• Climate Plan
https://arctic-news.blogspot.com/p/climateplan.html

• Smoke Covers Much Of Siberia
https://arctic-news.blogspot.com/2019/07/smoke-covers-much-of-siberia.html

• Extreme Weather
https://arctic-news.blogspot.com/p/extreme-weather.html

• Albedo and more
https://arctic-news.blogspot.com/p/albedo.html

• Radiative Heating of an Ice‐Free Arctic Ocean, by Kristina Pistone et al. (2019)
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2019GL082914

• High cloud coverage over melted areas dominates the impact of clouds on the albedo feedback in the Arctic, by Min He et al. (2019)
https://www.nature.com/articles/s41598-019-44155-w

• ESD Reviews: Climate feedbacks in the Earth system and prospects for their evaluation, by Christoph Heinze et al. (2019)
https://www.earth-syst-dynam.net/10/379/2019/esd-10-379-2019-discussion.html

• Contribution of sea ice albedo and insulation effects to Arctic amplification in the EC-Earth Pliocene simulation, by Jianqiu Zheng et al. (2019)
https://www.clim-past.net/15/291/2019

• Far-infrared surface emissivity and climate, by Daniel Feldman et al. (2014)
https://www.pnas.org/content/111/46/16297.abstract

• Extreme Weather
https://arctic-news.blogspot.com/p/extreme-weather.html

• Feedbacks in the Arctic
https://arctic-news.blogspot.com/p/feedbacks.html

• Rain Storms Devastate Arctic Ice And Glaciers
https://arctic-news.blogspot.com/2015/01/rain-storms-devastate-arctic-ice-and-glaciers.html

• A rise of 18°C or 32.4°F by 2026?
https://arctic-news.blogspot.com/2019/02/a-rise-of-18c-or-324f-by-2026.html

• As El Niño sets in, will global biodiversity collapse in 2019?
https://arctic-news.blogspot.com/2018/11/as-el-nino-sets-in-will-global-biodiversity-collapse-in-2019.html

• Dangerous situation in Arctic
https://arctic-news.blogspot.com/2018/11/dangerous-situation-in-arctic.html

• Warning of mass extinction of species, including humans, within one decade
https://arctic-news.blogspot.com/2017/02/warning-of-mass-extinction-of-species-including-humans-within-one-decade.html



[Author: Sam Carana] [Category: Arctic, biomass, buffer, burning, extent, fire, Greenland, latent heat, Malcolm Light, methane, ocean, Paul Beckwith, sea ice, soot, thickness, volume]

[*] [+] [-] [x] [A+] [a-]  
[l] at 9/14/19 2:59pm
Smoke covers much of Siberia, as shown by the NASA Worldview image dated July 25, 2019.


The enormous intensity of the fires is illustrated by the image below, showing carbon monoxide (CO) levels as high as 80,665 ppb on July 25, 2019.


The image below shows that, at that same spot on July 25, 2019, carbon dioxide (CO₂) levels were as high as 1205 ppm.


The image below shows that aerosols from biomass burning were at the top end of the scale.


When soot from fires settles on snow and ice, it darkens the surface, resulting in more sunlight getting absorbed (instead of reflected back into space, as was previously the case), thus further speeding up the melting.

The loss of sea ice north of Greenland is particularly worrying, since this is the area where once the thickest sea ice was present. The image below shows the situation on July 24, 2019.


The image below shows the sea ice disappearing north of Greenland and Ellesmere Island on July 25, 2019.


The huge recent fall in sea ice volume is illustrated by the graph below, by Wipneus.


The naval.mil animation below illustrates the rapid fall in sea ice thickness, showing 30-day period including seven forecasts up to August 1, 2019.


The combination image below shows sea ice thickness forecasts for July 25, 2019, and for August 1, 2019.


The video below, by Robin Westenra, further illustrates our predicament.


The situation is dire and calls for comprehensive and effective action, as described in the Climate Plan.


Links


• Climate Plan
https://arctic-news.blogspot.com/p/climateplan.html



[Author: Sam Carana] [Category: carbon dioxide, carbon monoxide, fire, sea ice, soot, volume]

[*] [+] [-] [x] [A+] [a-]  
[l] at 9/14/19 2:03pm
This is the most important message ever posted.
Please share it widely and add your comments!
(click on share in the box underneath this post)

A catastrophe of unimaginable proportions is unfolding. Life is disappearing from Earth and runaway heating could destroy all life. At 5°C heating, most life on Earth will have disappeared. When looking only at near-term human extinction, 3°C will likely suffice. Study after study is showing the severity of the threat that too many keep ignoring or denying it, at the peril of the world at large. Have a look at the following:

Crossing the 2°C guardrail

The image below shows two trends, a long-term trend (blue) and a short-term trend (red) that better reflects El Niño peaks.


The image confirms an earlier analysis that it could be 1.85°C (or 3.33°F) hotter in 2019 than in 1750.

June 2019 was the hottest June on record, it was 2.08°C (or 3.74°F) hotter than the annual global mean 1980-2015, which was partly due to seasonal variations, as the image below shows.


This gives an idea of how hot the year 2019 will be. July 2019 is on course to be hottest month on record, further highlighting the danger that a strengthening El Niño could cause a steep temperature rise soon.

Remember the 2015 Paris Agreement, when politicians pledged to act on the threat of climate change, including by “Holding the increase in the global average temperature to well below 2°C above pre-industrial levels . . . ”

The image at the top highlights the danger of a rapid temperature rise occurring soon and of the 2°C (or 3.6°F) guardrail getting crossed soon, i.e. in 2020 (the blue long-term trend, based on 1880-June2019 data), or in 2019 (red trend, based on 2011-June 2019 data). Moreover, the danger is that temperatures will not come down after crossing 2°C, but instead will continue in a steep rise toward 3°C.


We are already at about 2°C above pre-industrial

In the image at the top, NASA data are adjusted by 0.57°C. Such adjustment is appropriate for a number of reasons.  First of all, NASA uses the period 1951-1980 as their default baseline. Most of the adjustment is due to the use of a 1750 baseline, which better reflects pre-industrial.

Furthermore, air temperatures over oceans and higher polar anomalies are more appropriate, as confirmed by a recent study that concludes that missing data have been responsible for an underestimation of global warming by 0.1°C.

The image on the right, from a recent study, shows how much difference it makes when using surface air temperatures globally (black line), versus when sea surface temperatures are used for oceans (dark blue line) and in case of incomplete coverage (light blue line).

At a 3°C rise, humans will likely go extinct

The image at the top shows two trends, a long-term trend in blue and a short-term trend in red which follows variations such as El Niño more closely. The blue trend points at a 3°C (or 5.4°F) rise by 2026, while the red trends shows that a 3°C rise could eventuate as early as in 2020 in case of a persistently strengthening El Niño.

At a 3°C rise, humans will likely go extinct, as habitat for humans (and many other species) will disappear. Such a rise will cause a rapid decline of the snow and ice cover around the globe, in turn making that less sunlight gets reflected back into space. Associated changes are discussed in more detail at this page and this page, and include that the jet stream will further get out of shape, resulting in more extreme weather events such as droughts, heatwaves and firestorms. Changes to the jet stream will also contribute to a further strengthening of storms, which threatens to push large amounts of hot, salty water into the Arctic Ocean, triggering eruptions of more and more seafloor methane.

From a 4°C rise, Earth will have a moist-greenhouse scenario

As the temperature rise gains further momentum, runaway heating may well turn Earth into a lifeless planet. This danger was discussed in a 2013 post, warning that, at 4°C rise, Earth will enter a moist-greenhouse scenario and without anything stopping the rise, it will continue to eventually destroy the ozone layer and the ice caps, while the oceans would be evaporating into the atmosphere's upper stratosphere and eventually disappear into space.

[ from an earlier post ] At 5°C rise, most life on Earth will be extinct

At 5°C rise, most life on Earth will be extinct. A 2018 study by Strona & Bradshaw indicates that most life on Earth will disappear with a 5°C rise (see box on the right).

As the temperature keeps rising, chances are that all life on Earth will go extinct, as Earth would be left with no ozone layer to protect life from deadly UV-radiation. Furthermore, Earth would no longer have water, an essential building block of life. Soil moisture, ground water and water in oceans would evaporate and eventually disappear into space, as discussed in an earlier post.

There are several reasons why the temperature will keep rising well beyond a 5°C rise, as discussed below.

Could Earth go the same way as Venus?

At first glace, such a lifeless planet scenario may seem unlikely, as Earth did experience high temperatures before, but each time it did cool down again. While many species went extinct as a result of steep temperature rises, each time some species did survive the mass extinction events in the past.

This time, however, the situation is much more dire than during previous mass extinctions, and temperatures could keep rising, due to:
  • Brighter Sun - The sun is now much brighter than it was in the past;
  • No sequestration - The rapidity of the rise in greenhouse gases and of the associated temperature rise leaves species little or no time to adapt or move, and leaving no time for sequestration of carbon dioxide by plants and by deposits from other species, nor for formation of methane hydrates at the seafloor of oceans; 
  • No weathering - The rapidity of the rise also means that weathering doesn't have a chance to make a difference. Rapid heating is also dwarfing what weathering (and vegetation) can do to reduce carbon dioxide levels; and
  • Methane - Due to the rapid temperature rise, there is also little or no time for methane to get decomposed. Methane levels will skyrocket, due to fires, due to decomposition of dying vegetation and due to releases from melting terrestrial permafrost and from the seafloor (see more on methane further below). 

The methane threat

Our predicament

The predicament of this geological time is that methane in hydrates has been accumulating for a long time, especially in the Arctic, where there is little or no hydroxyl present in the atmosphere in the first place, while some 75% of the East Siberian Arctic Shelf (ESAS) is shallower than 50 m, as also discussed in this earlier post and this earlier post.

As more methane rises abruptly from the seafloor in plumes, the chance reduces that it will get decomposed in the water, and especially so in the Arctic where long uni-directional sea currents prevent microbes to return to the location of such plumes.

Shallow seas (light blue areas on the image on the right) make waters prone to warm up quickly during summer peaks, allowing heat to penetrate the seabed.

Methane rising through shallow waters will also enter the atmosphere more quickly. Elsewhere in the world, releases from hydrates underneath the seafloor will largely be oxidized by methanotroph bacteria in the water. In shallow waters, however, methane released from the seabed will quickly pass through the water column.

Large abrupt releases will also quickly deplete the oxygen in the water, making it harder for bacteria to break down the methane.

[ from an earlier post ] The image on the right highlights methane's accelerating rise, showing levels of methane (CH₄), carbon dioxide (CO₂) and nitrous oxide (N₂O) in the atmosphere that are, respectively, 257%, 146% and 122% their 1750 levels.

Hydroxyl depletion extending methane's lifetime

The graph on the right also shows that methane levels in the atmosphere remained almost unchanged during the period 2000-2007. One explanation for this is that, as the world heated up due to the rising levels of greenhouse gases in the atmosphere, the amount of water vapor in the atmosphere rose accordingly (at a rate of 7% for each degree Celsius rise), which translated into more hydroxyl getting produced that resulted in more methane getting decomposed. So, while methane emissions kept rising, the amount of methane in the atmosphere remained relatively stable, as more methane got decomposed. Eventually, in 2007, the continued rise in methane emissions started to overwhelm the capacity of hydroxyl to decompose methane.   

The danger is that, as huge amounts of methane get released rapidly, hydroxyl depletion will extend its lifetime, in turn further accelerating heating and resulting in further releases of seafloor methane.

Methane's GWP

Measured over a few years, methane's global warming potential (GWP) is very high. The image on the right, from IPCC AR5, shows that over a 10-year timescale, the current global release of methane from all anthropogenic sources exceeds all anthropogenic carbon dioxide emissions as agents of global warming; that is, methane emissions are more important than carbon dioxide emissions for driving the current rate of global warming.

The values for methane's GWP that are used in the image on the right are also used in the image below, which shows that over the first few years, methane's GWP is more than 150 times higher than carbon dioxide.


Above image is actually conservative, as the IPCC also gives higher values for methane's GWP in AR5, i.e. for fossil methane and when including climate change feedbacks, while there also is additional warming due to the carbon dioxide that results from methane's oxidation. Furthermore, research published in 2016 and 2018 found methane to be more potent than IPCC's GWP for methane in AR5, so it seems appropriate to use 150 as methane's GWP for periods of a few years.

Self-reinforcing feedback loops further accelerate heating in the Arctic and just one of them, seafloor methane, could suffice to cause runaway heating.

from an earlier post (2014)   As the image below shows, in which a GWP of 150 for methane is used, just the existing carbon dioxide and methane, plus seafloor methane releases, would suffice to trigger the clouds feedback tipping point to be crossed that by itself could push up global temperatures by 8°C, within a few years.


As described on above image and in an earlier post, a rapid temperature rise could result from a combination of elements, including albedo changes, loss of sulfate cooling, and methane released from destabilizing hydrates contained in sediments at the seafloor of oceans.

[ from an earlier post ] In the video below, Professor Peter Wadhams and Stuart Scott discuss the threat of large methane releases (recorded March 2019, published July 2019).


Seafloor methane releases could be triggered soon by strong winds causing an influx of warm, salty water into the Arctic ocean, as described in an earlier post and discussed in the 2017 video below. In the above images, methane is responsible for a temperature rise of as much as 1.1°C in a matter of years, but the rise won't stop there. A study published in 2012 calculates that 1000-fold methane increase could occur resulting in a rise of as much as 6°C within 80 years, with more to follow after that.



Youtube video by RT America
In the May 2019 video below, Professor Guy McPherson and Thom Hartmann discuss our predicament.



The situation is dire and calls for comprehensive and effective action, as described in the Climate Plan.


Links

• Extinction Alert
https://arctic-news.blogspot.com/2019/02/extinction-alert.html

• Geographical Distribution of Thermometers Gives the Appearance of Lower Historical Global Warming - by Rasmus Benestad et al.
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2019GL083474

• July on course to be hottest month ever, say climate scientists - The Guardian
https://www.theguardian.com/environment/2019/jul/16/july-on-course-to-be-hottest-month-ever-say-climate-scientists

• Radiative forcing of carbon dioxide, methane, and nitrous oxide: A significant revision of the methane radiative forcing - by Maryam Etminan et al. (2018)
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2016GL071930

• Large regional shortwave forcing by anthropogenic methane informed by Jovian observations - by William Collins et al. (2016)
https://advances.sciencemag.org/content/4/9/eaas9593

• Estimating and tracking the remaining carbon budget for stringent climate targets - by Joeri Rogelj et al.
https://www.nature.com/articles/s41586-019-1368-z

• As El Niño sets in, will global biodiversity collapse in 2019?
https://arctic-news.blogspot.com/2018/11/as-el-nino-sets-in-will-global-biodiversity-collapse-in-2019.html

• Methane hydrates
https://methane-hydrates.blogspot.com/2013/04/methane-hydrates.html

• Damage of Land Biosphere due to Intense Warming by 1000-Fold Rapid Increase in Atmospheric Methane: Estimation with a Climate–Carbon Cycle Model, by Atsushi Abata et al. (2012)
https://journals.ametsoc.org/doi/full/10.1175/JCLI-D-11-00533.1

• Extreme weather
https://arctic-news.blogspot.com/p/extreme-weather.html

• Feedbacks in the Arctic
https://arctic-news.blogspot.com/p/feedbacks.html

• Albedo and Latent Heat
https://arctic-news.blogspot.com/p/albedo.html

• Earth is on the edge of runaway warming
https://arctic-news.blogspot.com/2013/04/earth-is-on-the-edge-of-runaway-warming.html

• When Will We Die?
https://arctic-news.blogspot.com/2019/06/when-will-we-die.html

• Warning of mass extinction of species, including humans, within one decade
http://arctic-news.blogspot.com/2017/02/warning-of-mass-extinction-of-species-including-humans-within-one-decade.html

• Climate Plan
https://arctic-news.blogspot.com/p/climateplan.html



[Author: Sam Carana] [Category: El Nino, heating, rise, temperature]

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