Thursday, June 3, 2021

Greenhouse gas levels keep rising at accelerating rates

At the Paris Agreement in 2015, politicians pledged to limit the global temperature rise from pre-industrial levels to 1.5°C and promised to stop rises in greenhouse gas emissions as soon as possible and to make rapid reductions in accordance with best available science, to achieve a balance between people's emissions by sources and removals by sinks of greenhouse gases in the second half of this century. 

Yet, greenhouse gas levels keep rising and the rise appears to be accelerating. 

Carbon Dioxide

The annual mean global growth rate of carbon dioxide (CO₂) has been increasing over the years (see above image). The February 2021 global CO₂ level was 2.96 ppm higher than the February 2020 global CO₂ level (image left).
The March 2021 global CO₂ level was 2.89 ppm higher than the March 2020 global CO₂ level (image left), again much higher than the average annual growth rate over the past decade. No discernible signal in the data was caused by restrictions associated with the COVID-19 pandemic.

More recent values are available for Mauna Loa, Hawaii. As the image on the right shows, the monthly average CO₂ level at Mauna Loa was 419.13 ppm for May 2021, while the weekly average was as high as 420.01 ppm (for the week ending at May 1, 2021). 

On April 8, 2021, CO₂ levels at Mauna Loa, Hawaii, reached a level of 421.36 ppm, while several hourly averages recorded in early April were approaching 422 ppm (see earlier post).

According to NOAA, the atmospheric burden of CO₂ is now comparable to where it was during the Pliocene Climatic Optimum, between 4.1 and 4.5 million years ago, when CO₂ was close to, or above 400 ppm. During that time, the average temperature was about 4°C (7°F) higher than in pre-industrial times, and sea level was about 24 m (78 feet) higher than today.

Methane
 
The 2020 global annual methane (CH₄) growth rate of 15.85 ppb was the highest on record. The global CH₄ level in January 2021 was 1893.4 ppb, 20 ppb higher than the January 2020 level. 

The image at the top shows a trend indicating that CH₄ could reach a level of 4000 ppb in 2026, which at a 1-year GWP of 200 translates into 800 ppm CO₂e, so just adding this to the current CO₂ level would cause the Clouds Tipping Point at 1200 CO₂e to be crossed, which in itself could raise global temperatures by 8°C, as described in an earlier post. 

Nitrous Oxide

The 2020 global annual nitrous oxide (N₂O) growth rate of 1.33 ppb was the highest on record. The global N₂O level in January 2021 was 333.9 ppb, 1.4 ppb higher than the January 2020 level. 

Greenhouse gas levels are accelerating, despite promises by politicians to make dramatic cuts in emissions. As it turns out, politicians have not taken the action they promised they would take. 

Of course, when also adding nitrous oxide, the Clouds Tipping Point can get crossed even earlier.

Elements contributing to temperature rise

Next to rising greenhouse gas levels, there are further elements that can contribute to a huge temperature rise soon. 


As illustrated by above image by Nico Sun, the accumulation of energy going into melting the sea ice is at record high for the time of year. 



As illustrated by above combination image, the thickness of the sea ice is now substantially less than it used to be. The image compares June 1, 2021 (left), with June 1, 2015 (right). 

The animation on the right shows that sea ice is getting rapidly thinner, indicating that the buffer constituted by the sea ice underneath the surface is almost gone, meaning that further heat entering the Arctic Ocean will strongly heat up the water.

As described in an earlier post, this can destabilizate methane hydrates in sediments at the seafloor of the Arctic Ocean, resulting in eruption of methane from these hydrates and from methane that is located in the form of free gas underneath such hydrates. 

Such methane eruptions will first of all heat up the Arctic, resulting in loss of Arctic sea ice's ability to reflect sunlight back into space (albedo feedback), in disappearing glaciers and in rapidly thawing terrestrial permafrost (and the associated release of greenhouse gases).

The Snowball Effect


Temperatures are rising and they are rising at accelerating pace, especially in the Arctic. A strong El Niño and a distortion in the jet stream could cause the latent heat and methane hydrates tipping points to be crossed soon, causing many feedbacks to kick in with ever greater ferocity, and pushing up the global temperature beyond 3°C, 4°C and 5°C above pre-industrial, like a snowball that keeps growing in size while picking up ever more snow, as it is racing down a very steep slope.

Crossing of tipping points and further events and developments can combine with feedbacks into a snowball effect of rapidly rising temperatures.

Feedbacks include changes to the Jet Stream that result in ever more extreme weather events such as storms and forest fires. Such events can cause huge emissions of greenhouse gases. 

Temperatures can also be expected to rise over the next few years as sulfate cooling decreases. Aerosols can further cause additional warming if more black carbon and brown carbon gets emitted due to more wood getting burned and more forest fires taking place. Black carbon and brown carbon have a net warming effect and can settle on snow and ice and speed up their decline.

Therefore, the 8°C rise as a result of crossing the Clouds Tipping Point would come on top of the warming due to other elements, and the total rise could be as high as 18°C or 32.4°F from preindustrial, as ilustrated by the image on the right, from an earlier post.

Very high sea surface temperature anomalies

Meanwhile, sea surface temperatures on the Northern Hemisphere keep rising. The image below shows that sea surface temperature anomalies off the North American east coast (at the green circle) were as high as as 13.7°C (24.7°F) on June 3, 2021.


More heat is flowing from the tropics along the North American east coast toward the Arctic Ocean, carried by the Gulf Stream, as illustrated by the image on the right. 

In conclusion, there could be a huge temperature rise by 2026. 

At a 3°C rise, humans will likely go extinct, making it from some perspectives futile to speculate about what will happen beyond 2026. 

Even so, the right thing to do is to help avoid the worst things from happening, through comprehensive and effective action as described in the Climate Plan.


• NOAA: Trends in Greenhouse gases
https://gml.noaa.gov/ccgg/trends

• NOAA: Carbon dioxide peaks near 420 parts per million at Mauna Loa observatory

• Overshoot or Omnicide?
• Cryosphere Computing - by Nico Sun
https://cryospherecomputing.tk

• Arctic Ocean invaded by hot, salty water

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






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Sunday, May 30, 2021

Methane and the mass extinction of species

by Andrew Glikson

“The smart way to keep people passive and obedient is to strictly limit the spectrum of acceptable opinion, but allow very lively debate within that spectrum.” Noam Chomsky (1998).

The level of atmospheric methane, a poisonous gas considered responsible for major mass extinction events in the past, has nearly tripled during the 20-21st centuries, from ~722 ppb (parts per billion) to above ~1866 ppb, currently reinforced by coal seam gas (CSG) emissions. As the concentration of atmospheric methane from thawing Arctic permafrost, from Arctic sediments and from marshlands worldwide is rising, the hydrocarbon industry, subsidized by governments, is progressively enhancing global warming by extracting coal seam gas in defiance of every international agreement.

Methane (CH₄), a powerful greenhouse gas ~80 times the radiative power of carbon dioxide (CO₂) when fresh, sourced in from anaerobic decomposition in wetlands, rice fields, emission from animals, fermentation, animal waste, biomass burning, charcoal combustion and anaerobic decomposition of organic waste, is enriched by melting of leaking permafrost, leaks from sediments of the continental shelf (Figure 1) and extraction as coal seam gas (CSG). The addition to the atmosphere of even a part of the estimated 1,400 billion tons of carbon (GtC) from Arctic permafrost would destine the Earth to temperatures higher than 4 degrees Celsius and thereby demise of the biosphere life support systems.


During the last and present centuries, global methane concentrations have risen from approximately ~700 parts per billion (ppb) to near-1900 ppb, an increase by a factor of ~2.7, the highest rate in the last 800,000 years.


Since the onset of the Industrial age global emissions of carbon have reached near-600 billion tonnes of carbon (>2100 billion tonnes CO₂) at a rate faster than during the demise of dinosaurs. According to research published in Nature Geoscience, CO₂ is being added to the atmosphere at least ten times faster than during a major warming event about 55 million years ago.

Australia, possessing an abundance of natural gas, namely methane resources, is on track to become the world's largest exporter. Leaks from hydraulic fracturing (fracking) production wells, transport and residues of combustion are bound to contribute significantly to atmospheric methane. However, despite economic objections, not to mention accelerating global warming, natural gas from coal seam gas, liquefied to -161°C, is favored by the government for domestic use as well as exported around the world.

In the Hunter Valley, NSW, release of methane from open-cut coal mining reached above 3000 ppb. In the US methane released in some coal seam gas fields constitutes between 2 and 17 per cent of the emissions.

While natural gas typically emits between 50 and 60 percent less CO₂ than coal when burned, the drilling and extraction of natural gas from wells, fugitive emissions, leaks from transportation in pipelines result in enrichment of the atmosphere in methane, the main component of natural gas, 34 times stronger than CO₂ at trapping heat over a 100-year period and 86 times stronger over 20 years. So, while natural gas when burned emits less CO₂ than coal, that doesn’t mean that it’s clean – the reason summed up in one word: methane.

Global warming triggered by the massive release of CO₂ may be catastrophic, but release of CH₄ from methane hydrates may be apocalyptic. According to Brand et al. (2016), the release of methane from permafrost and shelf sediment has constituted the ultimate source and cause for the dramatic life-changing global warming. The mass extinction at the end of the Permian 251 million years ago, when 96 percent of species was lost, holds an important lesson for humanity regarding greenhouse gas emissions, global warming, and the life support system of the planet (Brand et al. 2016, Methane Hydrate: Killer cause of Earth's greatest mass extinction).

The pledge for zero-emissions by 2050 is questioned as governments continue to subsidize, mine and export hydrocarbons. Examples include Saudi-Arabia, the Gulf States, Russia, Norway and Australia. A mostly compliant media highlights a zero-emission pledge, but is reluctant to report the scale of exported emissions as well as the ultimate consequences of the open-ended rise of global temperatures.

Norway, a country committed to domestic clean energy, is conducting large scale drilling for Atlantic and Arctic oil. Australia, the fourth-largest producer of coal, with 6.9% of global production, is the biggest net exporter, with 32% of global exports in 2016. 23 new coal projects are proposed n the Hunter Valley, NSW, with a production capacity equivalent to 15 Adani-sized mines.

Australian electricity generation is dominated by fossil fuel and about 17% renewable energy. Fossil fuel subsidies hit $10.3 billion in 2020-21, about twice the investment in solar energy in 2019-2020. State Governments spent $1.2 billion subsidizing exploration, refurbishing coal ports, railways and power stations and funding “clean coal” research, ignoring the pledge for “zero emissions by 2050”.

The pledge overlooks the global amplifying effects of cumulative greenhouse gases. At the current rate of emissions, atmospheric CO₂ levels would be near 500 ppm CO₂ by 2050, generating warming of the oceans (expelling CO₂), decreased albedo due to melting of ice, release of methane, desiccated vegetation and extensive fires.

Claims of “clean coal”, “clean gas” and “clean hydrogen” ignore the contribution of these methods to the rise in greenhouse gases. Coal seam gas has become an additional source of methane which has an 80 times more powerful greenhouse effect than CO₂. This adds to the methane leaked from Arctic permafrost, with atmospheric methane rising from ~ 600 parts per billion early last century to higher than 2000 ppb. In the Hunter Valley, NSW, release of methane from open-cut coal mining reached above 3000 ppb. In the US, methane released in some coal seam gas fields constitutes between 2 and 17 per cent of the emissions.

The critical index of global warming, rarely mentioned by politicians or the media, is the atmospheric concentration of CO₂. During 2020-2021 CO₂ rose from 416.45 to 419.05 parts per million at a rate of 2.6 ppm/year, a trend unprecedented in the geological record of the last 55 million years. The combined effects of greenhouse gases such as cabon dioxide (CO₂), methane (CH₄) and nitrous oxide (N₂O) have reached near ~500 ppm CO2-equivalent.

Since 1880, the world has warmed by 1.09 degrees Celsius on average, near ~1.5°C on the continents and ~2.2°C in the Arctic, with the five warmest years on record during 2015-2020. Since the 1980s, the wildfire season has lengthened across a quarter of the world's vegetated surface. As extensive parts of Earth are burning, “forever wars” keep looming. 

It is not clear how tracking toward +4 degrees Celsius by the end of the century can be arrested. A level of +4°C above pre-industrial temperature endangers the very life support systems of the planet. The geological record indicates past global heating events on a scale and rate analogous to the present have led to mass extinctions of species. According to Professor Will Steffen, Australia’s top climate scientist “we are already deep into the trajectory towards collapse”. While many scientists are discouraged by the extreme rate of global heating, it is left to a heroic young girl to warn the world of the greatest calamity since a large asteroid impacted Earth some 66 million years ago.


Andrew Glikson
A/Prof. Andrew Glikson

Earth and Paleo-climate scientist
The University of New South Wales,
Kensington NSW 2052 Australia


Books:
The Asteroid Impact Connection of Planetary Evolution
http://www.springer.com/gp/book/9789400763272
The Archaean: Geological and Geochemical Windows into the Early Earth
http://www.springer.com/gp/book/9783319079073
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
Asteroids Impacts, Crustal Evolution and Related Mineral Systems with Special Reference to Australia
http://www.springer.com/us/book/9783319745442
The Event Horizon: Homo Prometheus and the Climate Catastrophe
https://www.springer.com/gp/book/9783030547332


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Saturday, May 22, 2021

Arctic Ocean invaded by hot, salty water


Sea surface temperatures on the Northern Hemisphere have been rising dramatically over the years, as illustrated by above image, indicating that the latent heat tipping point is getting crossed, while the methane hydrates tipping point could get crossed soon, depending on developments.

At the moment, the surface temperature of most of the Arctic ocean's is still below 0°C.

Heat is entering the Arctic Ocean from the south, as illustrated by the image on the right. Hot, salty water is entering the Arctic Ocean from the Atlantic Ocean as currents dive underneath the ice, causing the ice to melt from below. 
[ click on images to enlarge ]

The image on the right, from the NSIDC article A step in our Spring, compares sea ice age between March 12 to 18 for the years 1985 (a) and 2021 (b).

The bottom graph (c) shows a time series from 1985 to 2021 of percent ice coverage of the Arctic Ocean domain. The Arctic Ocean domain is depicted in the inset map with purple shading.

At the end of the ice growth season in mid-March, 73.3% of the Arctic Ocean domain was covered by first-year ice, while 3.5% was covered by ice 4+ years old. 

This compares to 70.6% and 4.4% respectively in March 2020.

In March 1985, near the beginning of the ice age record, the Arctic Ocean region was comprised of nearly equal amounts of first-year ice (39.3%) and 4+ year-old ice (30.6%).

Sea ice that hasn't yet survived a summer melt season is referred to as first-year ice. This thin, new ice is vulnerable to melt and disintegration in stormy conditions. Ice that survives a summer melt season can grow thicker and less salty, since snow that thickens the ice contains little salt. Thickness and salt content determine the resistance of the ice to melt. Multiyear ice is more likely to survive temperatures that would melt first-year ice, and to survive waves and winds that would break up first-year ice.

The image on the right shows a forecast of the thickness of the sea ice, run on May 20, 2021 and valid for May 21, 2021. 

An area is visible north of Severnaya Zemlya toward the North Pole where thickness is getting very thin, while there is one spot where the ice has virtually disappeared. 

The spot is likely a melting iceberg, the animation on the right shows that the spot has been there for quite a few days, while the freshwater in this spot appears to result from melting amid salty water. 

Overall, sea ice is getting very thin, indicating that the buffer constituted by the sea ice underneath the surface is almost gone, meaning that further heat entering the Arctic Ocean will strongly heat up the water. 

As the animation underneath on the right shows, freshwater is entering the Arctic Ocean due to runoff from land, i.e. rainwater from rivers, meltwater from glaciers and groundwater runoff from thawing permafrost. 

At the same time, very salty water is entering the Arctic Ocean from the Atlantic Ocean. 

The map below shows how salty and hot water from the Atlantic Ocean enters the Arctic Ocean along two currents, flowing on each side of Svalbard, and meeting at this area north of Severnaya Zemlya where thickness is getting very low. 

The blue color on the map indicates depth (see scale underneath). 

The image below, by Malcolm Light and based on Max & Lowrie (1993), from a recent post, shows vulnerable Arctic Ocean slope and deep water methane hydrates zones below 300 m depth. 

Malcolm Light indicates three areas: 
Area 1. Methane hydrates on the slope;
Area 2. Methane hydrates on the abyssal plane; 
Area 3. Methane hydrates associated with the spreading Gakkel Ridge hydro-thermal activity (the Gakkel Riidge runs in between the northern tip of Greenland and the Laptev Sea). 


The freezing point of freshwater is 0°C or 32°F. For salty water, the freezing point is -2°C or 28.4°F.

During April 2021, sea ice was about 160 cm thick.

In June and July 2021, thickness will fall rapidly, as illustrated by the image on the right by Nico Sun. 

Sea ice acts as a buffer, by consuming energy in the process of melting, thus avoiding that this energy causes a temperature rise of the water. 

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 and remain at zero°C. The amount of energy that is consumed in the process of melting the ice is as much as it takes to heat an equivalent mass of water from zero°C to 80°C.

The accumulated ice melt energy until now is the highest on record, as illustrated by the image on the right, by Nico Sun.

The image below further illustrate the danger. As the temperature of the water keeps rising, more heat will reach sediments at the seafloor of the Arctic Ocean that contain vast amounts of methane, as discussed at this page and in this post.

Ominously, methane levels reached a peak of 2901 ppb at 469 mb on May 13, 2021. 

Research

In the extract of a 2008 paper, Natalia Shakhova et al. conclude: ". . we consider release of up to 50 Gt of predicted amount of hydrate storage as highly possible for abrupt release at any time."


The video below contains excerpts from Nick Breeze's interview with Natalia Shakhova at the European Geophysical Union in Vienna, 2012, on the likelihood and timeframe of a large methane release from the seafloor of the Arctic Ocean. 

Natalia Shakhova: "The total amount of methane in the atmosphere is about 5Gt. The amount of carbon in the form of methane in this Arctic shelf is - approximately - from hundreds to thousands Gt and, of course, only 1% of [such an] amount is required to double the atmospheric burden of methane."

"But to destabilize 1% of this carbon pool, I think, not much effort is needed, considering the state of the permafrost and the amount of methane involved, because what divides the methane from the atmosphere is a very shallow water column and the weakening permafrost, which is losing its ability to seal, to serve as a seal, and this is, I think, not a matter of thousands of years, it's a matter of decades, at most hundred years." 

(Natalia talks with Igor Semiletov)
Natalia Shakhova: "Just because this area is seismically and tectonically active, and there was some investigation that the tectonic activity was increasing, and the seismic activity, the destabiliation of the ground, just mechanical forcing destabiliation [may suffice to act as] additional pathway for this methane to escape. There are many factors that are very convincing for us [to conclude] that it might happen."

Elaborating on the timeframe.
Natalia Shakhova: "Not any time, any time sounds like it might happen today, it might happen tomorrow, the day after tomorrow . . " 
Igor Simelitov: "It might!"


The image below was created with content from a 2019 paper by Natalia Shakhova et al. It concludes that methane releases could potentially increase by 3-5 orders of magnitude, considering the sheer amount of methane preserved within the shallow East Siberian Arctic Shelf seabed deposits and the documented thawing rates of subsea permafrost reported recently.

In a 2021 paper by researchers from Europe, Russia and the U.S., results from field research are published showing that methane is getting released from locations deep below the submarine permafrost. Lead author, Julia Steinbach, from Stockholm University, says: “The permafrost is a closed lid over the seafloor that’s keeping everything in place. And now we have holes in this lid.” 

In the video below, Nick Breeze interviews Igor Semiletov on methane plumes detected during this 2020 field research over the East Siberian Arctic Shelf (ESAS).


In the video below, Nick Breeze interviews Örjan Gustafsson on field research on methane in the East Siberian Arctic Shelf (ESAS)


In the video below, Peter Wadhams analyses the threat of Arctic methane releases.


In the video below, Guy McPherson discusses the situation.


In conclusion, temperatures could rise dramatically soon. A 3°C will likely suffice for humans to go extinct, making it in many respects rather futile to speculate about what will happen in the longer term. On the other hand, the right thing to do is to help avoid the worst things from happening, through comprehensive and effective action as described in the Climate Plan.

Links

• NOAA Climate at a Glance

• Danish Meteorological Institute - Arctic temperature
http://ocean.dmi.dk/arctic/meant80n.uk.php

• Freezing point of water - Climate Change: Arctic sea ice

• Arctic surface temperature

• NSIDC: A step in our Spring, image credit: T. Tschudi, University of Colorado, and W. Meier and J.S. Stewart, National Snow and Ice Data Center/Image by W. Meier

• Arctic sea ice - thickness and salinity - navy.mil
https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/arctic.html

• CryosphereComputing - by Nico Sun
https://cryospherecomputing.tk

• A 4.5 km resolution Arctic Ocean simulation with the global multi-resolution model FESOM 1.4 - by Qiang Wang et al. 

• Max, M.D. & Lowrie, A. 1993. Natural gas hydrates: Arctic and Nordic Sea potential. In: Vorren, T.O., Bergsager, E., Dahl-Stamnes, A., Holter, E., Johansen, B., Lie, E. & Lund, T.B. Arctic Geology and Petroleum Potential, Proceedings of the Norwegian Petroleum Society Conference, 15-17 August 1990, Tromso, Norway. Norwegian Petroleum Society (NPF), Special Publication 2 Elsevier, Amsterdam, 27-53.
https://www.elsevier.com/books/arctic-geology-and-petroleum-potential/vorren/978-0-444-88943-0

• Extinction by 2027- by Malcolm Light
https://arctic-news.blogspot.com/2021/05/extinction-by-2027.html


• Anomalies of methane in the atmosphere over the East Siberian shelf: Is there any sign of methane leakage from shallow shelf hydrates? - by Shakhova, Semiletov, Salyuk and Kosmach (2008)
https://www.cosis.net/abstracts/EGU2008/01526/EGU2008-A-01526.pdf

• Understanding the Permafrost–Hydrate System and Associated Methane Releases in the East Siberian Arctic Shelf - by Natalia Shakhova, Igor Semiletov and Evgeny Chuvilin 
https://www.mdpi.com/2076-3263/9/6/251

• A Massive Methane Reservoir Is Lurking Beneath the Sea 


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Tuesday, May 18, 2021

Extinction by 2027

by Malcolm Light

The greatest threat to humanity on Earth is the escalating Arctic atmospheric methane buildup, caused by the destabilization of subsea methane hydrates. This subsea Arctic methane hydrate destabilization will go out of control in 2024 and lead to a catastrophic heatwave by 2026.

While the source region for this subsea methane is in Russian waters, the hot ocean current setting them off is the northern extension of the Gulf Stream - North Atlantic Drift, the “Svalbard Current”, which makes United States and Canadian atmospheric pollution guilty of this looming catastrophic Global Extinction event.


References

Extinction by 2027 - Post by Malcolm Light and comments 
https://www.facebook.com/malcolm.light.50/posts/4013328748745929

Anomalies of methane in the atmosphere over the East Siberian shelf: Is there any sign of methane leakage from shallow shelf hydrates? - by Shakhova, Semiletov, Salyuk and Kosmach (2008) 
http://www.cosis.net/abstracts/EGU2008/01526/EGU2008-A-01526.pdf

Max, M.D. & Lowrie, A. 1993. Natural gas hydrates: Arctic and Nordic Sea potential. In: Vorren, T.O., Bergsager, E., Dahl-Stamnes, A., Holter, E., Johansen, B., Lie, E. & Lund, T.B. Arctic Geology and Petroleum Potential, Proceedings of the Norwegian Petroleum Society Conference, 15-17 August 1990, Tromso, Norway. Norwegian Petroleum Society (NPF), Special Publication 2 Elsevier, Amsterdam, 27-53. 
https://www.elsevier.com/books/arctic-geology-and-petroleum-potential/vorren/978-0-444-88943-0

Lucy-Alamo Projects - Hydroxyl Generation and Atmospheric Methane Destruction 

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Thursday, March 18, 2021

Overshoot or Omnicide?

Questions and Answers with Sam Carana


Above image shows a non-linear blue trend based on 1880-2020 NASA Land+Ocean data that are adjusted 0.78°C to reflect a pre-industrial base, to more fully reflect strong polar warming, and to reflect surface air temperatures over oceans. This blue trend highlights that the 1.5°C threshold was crossed in 2012 (inset), while the 2°C threshold looks set to be crossed next year and a 3°C rise could be reached at the end of 2026.

Overshoot?

The blue trend in the image at the top shows the temperature rise crossing 1.5°C in 2012. Could this have been a temporary overshoot? Could the trend be wrong and could temperatures come down in future, instead of continuing to rise, and could temperatures fall to such extent that this will bring the average temperature rise back to below 1.5°C?

To answer this question, let's apply the method followed by the IPCC and estimate the average temperature rise over a 30-year period that is centered around the start of 2012, i.e. from 1997 to the end of 2026. The IPPC used a 30-year period in its Special Report on Global Warming of 1.5 ºC, while assuming that, for future years, the current multi-decadal warming trend would continue (see image below).


As said, the image at the top shows the temperature rise crossing 1.5°C in 2012. For the average temperature over the 30-year period 1997-2026 to be below 1.5°C, temperatures would have to fall over the next few years. Even if the temperature for 2021 fell to a level as low as it was in 2018 and remained at that same lower level until end 2026, the 1997-2026 average would still be more than 1.5°C above pre-industrial. Furthermore, for temperatures to fall over the next few years, there would need to be a fall in concentrations of greenhouse gases over the next few years, among other things. Instead, greenhouse gas levels appear to be rising steadily, if not at accelerating pace.

What did the IPCC envisage? As the image below shows, the IPCC in AR5 did envisage carbon dioxide under RCP 2.6 to be 421 ppm in 2100, while the combined CO₂e for carbon dioxide, methane and nitrous oxide would be 475 ppm in 2100.


The image below, based on a study by Detlef van Vuuren et al. (2011), pictures pathways for concentrations of carbon dioxide, methane and nitrous oxide, for each of four Representative Concentration Pathways (RCPs).


Above image shows that, for RCP 2.6 to apply in the above study, there is little or no room for a rise in these greenhouse gases. In fact, the study shows that methane levels would have to be falling dramatically. At the moment, however, methane concentrations show no signs of falling and instead appear to be following if not exceeding RCP 8.5, as discussed in a recent post and as also illustrated by the images below. The IPCC used similar figures in AR5 (2013), as shown below. 


Greenhouse gas levels are rising

As the image below shows, the carbon dioxide (CO₂) level recorded at Mauna Loa, Hawaii, was 421.36 parts per million (ppm) on April 8, 2021. 


The N20 satellite recorded a methane peak of 2862 ppb on the afterrnoon of March 29, 2021, at 487.2 mb, as the image below shows.


A similarly high methane peak was recorded by the MetOp-1 satellite at 469 mb on the morning of April 4, 2021. 

Below are the highest daily mean methane levels recorded by the MetOp-1 satellite at selected altitudes on March 10 or 12, for the years 2013-2021, showing that methane levels are rising, especially at the higher altitude associated with 293 mb. 


Similarly, nitrous oxide levels show no signs of falling, as illustrated by the image below.


Methane grew 15.85 ppb in 2020, how fast could CO₂e rise? 

Rising greenhouse gas levels and associated feedbacks threaten to cause temperatures to keep rising, in a runaway scenario that cannot be reverted even if emissions by people were cut to zero.

Peaks in greenhouse gas levels could suffice to trigger the clouds feedback, which occurs when a CO₂e threshold of around 1,200 ppm is crossed, and the stratocumulus decks abruptly become unstable and break up into scattered cumulus clouds.

Once the clouds tipping point is crossed, it will be impossible to undo its impact, in line with the nature of a tipping point. In theory, CO₂ levels could come down after the stratocumulus breakup, but the stratocumulus decks would only reform once the CO₂ levels drop below 300 ppm.

A recent post repeated the warning that by 2026, there could be an 18°C rise when including the clouds feedback, while humans will likely go extinct with a 3°C rise and most life on Earth will disappear with a 5°C rise. In conclusion, once the clouds feedback gets triggered, it cannot be reverted by people, because by the time the clouds feedback starts kicking in, people would already have disappeared, so there won't be any people around to keep trying to revert it.

[ click on images to enlarge ]
Methane levels are rising rapidly. The image to the right shows a trend that is based on NOAA 2006-2020 annual global mean methane data and that points at a mean of 3893 ppb getting crossed by the end of 2026. 

Why is that value of 3893 ppb important? On April 8, 2021, carbon dioxide reached a peak of 421.36 ppm, i.e. 778.64 ppm away from the clouds tipping point at 1200 ppm, and 778.64 ppm CO₂e translates into 3893 ppb of methane at a 1-year GWP of 200. 

In other words, a methane mean of 3893 ppb alone could cause the clouds tipping point to get crossed, resulting in an abrupt 8°C temperature rise. 

Such a high mean by 2026 cannot be ruled out, given the rapid recent growth in mean annual methane levels (15.85 ppb in 2020, see inset on image). 

Additionally, there are further warming elements than just carbon dioxide and methane, e.g. nitrous oxide and water vapor haven't yet been included in the CO₂e total.

Moreover, it may not even be necessary for the global mean methane level to reach 3893 ppb. A high methane peak in one single spot may suffice and a peak of 3893 ppb of methane could be reached soon, given that methane just reached a peak of 2862 ppb, while even higher peaks were reached over the past few years, including a peak of 3369 ppb recorded on the afternoon of August 31, 2018. 

Abrupt stratocumulus cloud shattering 

[ click on images to enlarge ]
Catastrophic crack propagation is what makes a balloon pop. Could low-lying clouds similarly break up and vanish abruptly?

Could peak greenhouse gas concentrations in one spot break up droplets into water vapor, thus raising CO₂e and propagating break-up of more droplets, etc., to shatter entire clouds?

In other words, an extra burst of methane from the seafoor of the Arctic Ocean alone could suffice to trigger the clouds tipping point and abruptly push temperatures up by an additional 8°C.

Omnicide?

This brings the IPCC views and suggestions into question. As discussed above, for the average temperature to come down to below 1.5°C over the period 1997-2026, temperatures would need to fall over the next few years. What again would it take for temperatures to fall over the next few years?

Imagine that all emissions of greenhouse gases by people would end. Even if all emissions of greenhouse gases by people could magically end right now, there would still be little or no prospect for temperatures to fall over the next few years. Reasons for this are listed below, and it is not an exhaustive list since some things are hard to assess, such as whether oceans will be able to keep absorbing as much heat and carbon dioxide as they currently do.

By implication, there is no carbon budget left. Suggesting that there was a carbon budget left, to be divided among polluters and to be consumed over the next few years, that suggestion is irresponsible. Below are some reasons why the temperature is likely to rise over the next few years, rather than fall.

How likely is a rise of more than 3°C by 2026?

• The warming impact of carbon dioxide reaches its peak a decade after emission, while methane's impact over ten years is huge, so the warming impact of the greenhouse gases already in the atmosphere is likely to prevent temperatures from falling and could instead keep raising temperatures for some time to come.

• Temperatures are currently suppressed. We're in a La Niña period, as illustrated by the image below.


[ click on images to enlarge ]
As NASA describes, El Niño events occur roughly every two to seven years. As temperatures keep rising, ever more frequent strong El Niño events are likely to occur. NOAA anticipates La Niña to re-emerge during the fall or winter 2021/2022, so it's likely that a strong El Niño will occur between 2023 and 2025. 

• Rising temperatures can cause growth in sources of greenhouse gases and a decrease in sinks. The image below shows how El Niño/La Niña events and growth in CO₂ levels line up. 


• We're also at a low point in the sunspot cycle. As the image on the right shows, the number of sunspots can be expected to rise as we head toward 2026, and temperatures can be expected to rise accordingly. According to James Hansen et al., the variation of solar irradiance from solar minimum to solar maximum is of the order of 0.25 W/m⁻².

• Add to this the impact of a recent Sudden Stratospheric Warming event. We are currently experiencing the combined impact of three short-term variables that are suppressing the temperature rise, i.e. a Sudden Stratospheric Warming event, a La Niña event and a low in sunspots.

Over the next few years, in the absence of large volcano eruptions and in the absence of Sudden Stratospheric Warming events, a huge amount of heat could build up at surface level. As the temperature impact of the other two short-term variables reverses, i.e. as the sunspot cycle moves toward a peak and a El Niño develops, this could push up temperatures substantially. The world could be set up for a perfect storm by 2026, since sunspots are expected to reach a peak by then and since it takes a few years to move from a La Niña low to the peak of an El Niño period.

• Furthermore, temperatures are currently also suppressed by sulfate cooling. This impact is falling away as we progress with the necessary transition away from fossil fuel and biofuel, toward the use of more wind turbines and solar panels instead. Aerosols typically fall out of the atmosphere within a few weeks, so as the transition progresses, this will cause temperatures to rise over the next few years. Most sulfates are caused by large-scale industrial activity, such as coal-fired power plants and smelters. A significant part of sulphur emissions is also caused by volcanoes. Historically, some 20 volcanoes are actively erupting on any particular day. Of the 49 volcanoes that erupted during 2021, 45 volcanoes were still active with continuing (for at least 3 months) eruptions as at March 12, 2021.

• Also holding back the temperature rise at the moment is the buffer effect of thick sea ice in the Arctic that consumes heat as it melts. As Arctic sea ice thickness declines, more heat will instead warm up the Arctic, resulting in albedo changes, changes to the Jet Stream and possibly trigger huge releases of methane from the seafloor. The rise in ocean temperature on the Northern Hemisphere looks very threatening in this regard (see image on the right) and many of these developments are discussed at the extinction page. There are numerous further feedbacks that look set to start kicking in with growing ferocity as temperatures keep rising, such as releases of greenhouse gases resulting from permafrost thawing and the decline of the snow and ice cover. Some 30 feedbacks affecting the Arctic are discussed at the feedbacks page.

• The conclusion of study after study is that the situation is worse than expected and will get even worse as warming continues. Some examples: a recent study found that the Amazon rainforest is no longer a sink, but has become a source, contributing to warming the planet instead; another study found that soil bacteria release CO₂ that was previously thought to remain trapped by iron; another study found that forest soil carbon does not increase with higher CO₂ levels; another study found that forests' long-term capacity to store carbon is dropping in regions with extreme annual fires; a recent post discussed a study finding that at higher temperatures, respiration rates continue to rise in contrast to sharply declining rates of photosynthesis, which under business-as-usual emissions would nearly halve the land sink strength by as early as 2040; the post also mentions a study on oceans that finds that, with increased stratification, heat from climate warming less effectively penetrates into the deep ocean, which contributes to further surface warming, while it also reduces the capability of the ocean to store carbon, exacerbating global surface warming; finally, a recent study found that kelp off the Californian coast has collapsed. So, both land and ocean sinks look set to decrease as temperatures keep rising, while a 2020 study points out that the ocean sink will also immediately slow down as future fossil fuel emission cuts drive reduced growth of atmospheric CO₂. 

Where do we go from here?

[ image from earlier post ]
The same blue trend that's in the image at the top also shows up in the image on the right, from an earlier post, together with a purple trend and a red trend that picture even worse scenarios than the blue trend.

The purple trend is based on 15 recent years (2006-2020), so it can cover a 30-year period (2006-2035) that is centered around end December 2020. As the image shows, the purple trend points at a rise of 10°C by 2026, leaving little or no scope for the current acceleration to slow, let alone for the anomaly to return to below 2°C.

The red trend is based on a dozen recent years (2009-2020) and shows that the 2°C threshold could already have been crossed in 2020, while pointing at a rise of 18°C by 2025.

In conclusion, temperatures could rise by more than 3°C by the end of 2026, as indicated by the blue trend in the image at the top. At that point, humans will likely go extinct, making it in many respects rather futile to speculate about what will happen beyond 2026. On the other hand, the right thing to do is to help avoid the worst things from happening, through comprehensive and effective action as described in the Climate Plan.


Links

• Climate Plan

• NOAA Global Climate Report - February 2021 - Monthly Temperature Anomalies Versus El Niño

• NOAA Northern Hemisphere Ocean Temperature Anomaly

• NOAA Sunspots - solar cycle progression

• Smithsonian Institution - Volcanoes - current eruptions

• IPCC Special Report Global Warming of 1.5 ºC - Summary for Policy Makers

• IPCC AR5 WG1 Summary for Policymakers - Box SPM.1: Representative Concentration Pathways

• IPCC AR5, Climate Change (2013), Chapter 8

• The representative concentration pathways: an overview - by Detlef van Vuuren et al. (2011)

• Young people's burden: requirement of negative CO₂ emissions - by James Hansen et al. (2017)

• 2020: Hottest Year On Record

• What Carbon Budget?

• Most Important Message Ever

• High Temperatures October 2020

• Temperature keep rising

• More Extreme Weather

• Extinction

• Feedbacks

• Sudden Stratospheric Warming

• Possible climate transitions from breakup of stratocumulus decks under greenhouse warming - by Tapio Schneider  et al.

• Iron mineral dissolution releases iron and associated organic carbon during permafrost thaw - by Monique Patzner et al.

• Global maps of twenty-first century forest carbon fluxes - by Nancy Harris et al.

• A trade-off between plant and soil carbon storage under elevated CO2 - by César Terrer et al.

• Forests' long-term capacity to store carbon is dropping in regions with extreme annual fires

• Decadal changes in fire frequencies shift tree communities and functional traits - by Adam Pellegrini et al.

• NOAA - Annual Mean Growth Rate for Mauna Loa, Hawaii

• NOAA - Trends in Atmospheric Methane
https://www.esrl.noaa.gov/gmd/ccgg/trends_ch4

• The Climate Data Guide: Nino SST Indices - by Kevin Trenberth & NCAR Staff (Eds)
https://climatedataguide.ucar.edu/climate-data/nino-sst-indices-nino-12-3-34-4-oni-and-tni

• Historical change of El Niño properties sheds light on future changes of extreme El Niño - by Bin Wang et al. 

• NOAA - ENSO: Recent Evolution, Current Status and Predictions, April 12, 2021
https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf

• Upper Ocean Temperatures Hit Record High in 2020 - by Lijing Cheng et al.

• Large-scale shift in the structure of a kelp forest ecosystem co-occurs with an epizootic and marine heatwave - by Meredith McPherson et al.

• External Forcing Explains Recent Decadal Variability of the Ocean Carbon Sink - by Galen McKinley et al. (2020) 
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2019AV000149

• Maximum warming occurs about one decade after a carbon dioxide emission - by Katharine Ricke et al.

• Blue Ocean Event

• Confirm Methane's Importance

• FAQs

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