Tracking toward mass extinction

 by Andrew Glikson

Where “Two plus two equals five if the party says so” (George Orwell)
and when drilling methane wells reduces global warming

Having turned a blind eye to climate science, ignoring the evidence that extreme atmospheric carbon dioxide (CO₂), methane (CH₄) rise and ocean acidification have led to mass extinctions of species through time, humanity allows an exponential growth of carbon emissions to track toward a global suicide marked by false pretexts and betrayal by the powers that be. The evidence suggests unabated global warming will lead to 3.4 million Deaths Per Year by Century End, fatal consequences calling for a preemptive Nuremberg-like trial exposing the crimes leading to the looming climate suicide.

Note the future estimates of CO₂ levels.

[ Figure 1. Historic CO₂, by Owen Mulhern, image from Forster et al. (2017) ]

Note the sharp current and near-future temperature rise.

[ Figure 2. by Glen Fergus, from: Wikipedia - Temperature of Planet Earth ]

The rise in CO₂ in the atmosphere and oceans and the rise in ocean acidity (decline in pH).

[ Figure 3. As human activities have increased CO2 levels in our atmosphere (red line),
about a third of that CO2 has been absorbed by the ocean (green line), and
ocean pH has decreased (blue line). Adapted from NOAA by UC Museum of Paleontology. ]

According to the IPCC, as stated by the late Prof Will Steffen, Australia’s foremost climate scientist, if the exponential rise in greenhouse gas emissions continues we will already have crossed the upper limit that gives us a two-thirds chance of limiting warming to <2.0°C. Other scientists estimate that we have already missed the boat.

During the 200-plus years since the onset of the industrial revolution, the burning of fossil fuels, changing land use and deforestation increased the concentration of atmospheric CO₂. As the ocean absorbs about 30% of the CO₂ its surface acidity increased by -0.1 pH units on a logarithmic scale, resulting in rising concentration of hydrogen ions, a process with far reaching implications for the survival of marine organisms, altering ecosystems.

Ocean acidification affects marine life by dissolving shells and skeletons made from calcium carbonate. Organisms that produce calcium carbonate structures, like corals, sea urchins, sea snails and oysters, need to spend extra energy repairing damaged shells or thickening them to survive.

The onset of the Sixth mass extinction of species.

[ Figure 4. Cumulative vertebrate species recorded as extinct or extinct in the wild by the IUCN (2012). Dashed black line represents background rate. This is the ‘highly conservative estimate’. Source: Ceballos et al. (2015). ]

There have been five Mass Extinction events in the history of Earth's biodiversity, all caused by dramatic natural phenomena. The current rate of extinction is 10 to 100 times higher than in any of the previous mass extinctions in the history of Earth. Incorporating estimates of the true number of invertebrate extinctions leads to the conclusion that the rate vastly exceeds the background rate and that we may indeed be witnessing the start of the Sixth Mass Extinction Island species have suffered far greater rates than continental ones.

As systematic biologists, we encourage the nurturing of the innate human appreciation of biodiversity, but we reaffirm the message that the biodiversity that makes our world so fascinating, beautiful and functional is vanishing unnoticed at an unprecedented rate. These estimates reveal an exceptionally rapid loss of biodiversity over the last few centuries, indicating that a sixth mass extinction is already under way.

While multitudes of humanity are trying to escape climate disasters, such as Africa, or are engaged in fatal conflicts and geocidal wars, or are perched in front of electronic screens flaunting obscene hubris, cheap entertainment and commercial and political propaganda.

It is far from clear who, apart from the children, would be able to save life on Earth?

A/Prof. Andrew Y Glikson
Earth and climate scientist

Andrew Glikson

Books:

The Asteroid Impact Connection of Planetary Evolution
https://www.springer.com/gp/book/9789400763272
The Archaean: Geological and Geochemical Windows into the Early Earth
https://www.springer.com/gp/book/9783319079073
The Plutocene: Blueprints for a Post-Anthropocene Greenhouse Earth
https://www.springer.com/gp/book/9783319572369
The Event Horizon: Homo Prometheus and the Climate Catastrophe
https://www.springer.com/gp/book/9783030547332
Climate, Fire and Human Evolution: The Deep Time Dimensions of the Anthropocene
https://www.springer.com/gp/book/9783319225111
Evolution of the Atmosphere, Fire and the Anthropocene Climate Event Horizon
https://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
https://www.springer.com/us/book/9783319745442
The Fatal Species: From Warlike Primates to Planetary Mass Extinction
https://www.springer.com/gp/book/9783030754679
The Trials of Gaia. Milestones in the evolution of Earth with reference to the Antropocene
https://www.amazon.com.au/Trials-Gaia-Milestones-Evolution-Anthropocene/dp/3031237080

Is CMIP6 SSP585 the worst-case scenario?

The image below, adapted from Climate Reanalyzer, shows the temperature in the year 2100, in a CMIP6 SSP585 scenario. The image shows how much the temperature will have risen in 2100, at 2 meters above the surface and compared to the period 1979-2000. 

The image below shows a progressive temperature rise reaching 4.589°C in 2100 compared to the same period, i.e. 1979-2000 and in a CMIP6 SSP585 scenario.

The 1979-2000 period is relatively recent. The temperature has been rising for longer than that. The image below shows a progressive temperature rise reaching 4.91°C by 2100 in a CMIP6 SSP585 scenario when instead using a 1901-2000 period as a base.

The 1901-2000 period is also relatively recent, much later than pre-industrial. When using a pre-industrial base, the temperature rise will be well over 5°C.

As illustrated by the top image, the temperature rise over land will be much higher than over oceans, which makes the situation even more dire, given that most people live on land and could face a rise of  8°C by 2100 in a CMIP6 SSP585 scenario.

In a CMIP6 SSP585 scenario, temperatures are projected to keep rising strongly beyond 2100, as illustrated by the image below, from a 2016 paper by Brian O'Neill et al.

In the study by Brian O'Neill et al., CO₂ emissions keep rising until 2100, to then fall gradually to current levels, while the CO₂ concentration in the atmosphere keep rising, to remain at levels beyond 2000 ppm and result in a temperature rise of 8°C by 2300 in a CMIP6 SSP585 scenario.

Is CMIP6 SSP585 the worst-case scenario?

To check whether CMIP6 SSP585 is indeed the worst-case scenario, one can look at how fast CO₂ is rising. According to the IEA, global energy-related CO₂ emissions grew in 2023, reaching a new record high of 37.4 Gt (or 10.098 GtC). The image below, from a recent post, confirms the recent acceleration in CO₂ concentrations, while showing the potential for CO₂ concentration to cross 1200 ppm before the year 2060.

In other words, CO₂ may well be rising even faster than anticipated in a CMIP6 SSP585 scenario, while this scenario doesn't take into account the potential for CO₂e concentrations to cross 1200 ppm much earlier than 2100 (inset), e.g. before 2060 as illustrated by the red trend in the main image. Furthermore, CMIP6 SSP585 doesn't take into account that, in addition to the temperature rise resulting from high greenhouse gas concentrations, crossing the clouds tipping point at 1200 ppm in itself would push up temperatures by a further 8°C.

Indeed, the clouds tipping point could be crossed even earlier when also taking into account methane, nitrous oxide and further greenhouse gases, while there are additional developments such as organic carbon and inorganic carbon release from soils that could further raise both CO₂ concentrations and temperatures. The Extinction page and posts such as this one and this one warn about the potential for a temperature rise of well over 18°C unfolding as early as 2026. 

In conclusion, the temperature looks set to be rising higher and faster at accelerating rate, dwarfing anything seen in previous extinction events, as illustrated by the image below, from an earlier post.

"Now I am become Death, the destroyer of worlds."

The above image is a screenshot from the video (further above) in which physicist J. Robert Oppenheimer reflects on the first test of the atomic bomb. His haunting words mark the moment when science met conscience.

Similarly, climate change is a destroyer of worlds with unfathomable consequences, yet politicians refuse to heed the warnings, in an unprecedented breach of moral values, neglect of the precautionary principle, betrayal of trust and violation of the duty of care.

As a result, the IPCC persists with downplaying the potential for dangerous developments in efforts to hide the need for the most effective climate action. The IPCC keeps pointing at less effective policies such as support for BECCS and biofuel, while continuing to make it look as if there was a carbon budget to divide among polluters, as if polluters could continue to pollute for decades to come, as discussed in earlier posts such as this one.

Meanwhile, a 2018 study (by Strona & Bradshaw) indicates that most life on Earth will disappear with a 5°C rise. Humans, who depend for their survival on many other species, will likely go extinct with a 3°C rise, as illustrated by the image below, from an earlier post.

Climate Emergency Declaration

The situation is dire and the precautionary principle calls for rapid, comprehensive and effective action to reduce the damage and to improve the situation, as described in this 2022 post, where needed in combination with a Climate Emergency Declaration, as discussed at this group.

Links

• Climate Reanalyzer
https://climatereanalyzer.org

• The Scenario Model Intercomparison Project (ScenarioMIP) for CMIP6 - by Brian O'Neill et al. (2016)

https://gmd.copernicus.org/articles/9/3461/2016

• International Energy Agency (IEA) - CO2 Emissions in 2023 report
https://www.iea.org/reports/co2-emissions-in-2023

• September 2023, highest anomaly on record?

https://arctic-news.blogspot.com/2023/09/september-2023-highest-anomaly-on-record.html

• CO2 keeps accelerating
https://arctic-news.blogspot.com/2024/04/co2-keeps-accelerating.html

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

• Pre-industrial
https://arctic-news.blogspot.com/p/pre-industrial.html

• Clouds Feedback and the Clouds Tipping Point
https://arctic-news.blogspot.com/p/clouds-feedback.html

• The Threat
https://arctic-news.blogspot.com/p/threat.html

• Amplifying feedback loop between drought, soil desiccation cracking, and greenhouse gas emissions - by Farshid Vahedifard et al. 

https://iopscience.iop.org/article/10.1088/1748-9326/ad2c23
discussed on facebook at 
https://www.facebook.com/groups/arcticnews/posts/10161298567849679

• Size, distribution, and vulnerability of the global soil inorganic carbon - by Yuanyuan Huang et al. https://www.science.org/doi/10.1126/science.adi7918
discussed at facebook at 
https://www.facebook.com/groups/arcticnews/posts/10161354439024679

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

• When will humans go extinct? 
https://arctic-news.blogspot.com/2022/02/when-will-humans-go-extinct.html

• Shortcomings of IPCC AR6 WGIII - Mitigation of Climate Change
https://arctic-news.blogspot.com/2022/04/shortcomings-of-ipcc-ar6-wgiii-mitigation-of-climate-change.html

• Transforming Society

https://arctic-news.blogspot.com/2022/10/transforming-society.html

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

• Climate Emergency Declaration
https://arctic-news.blogspot.com/p/climate-emergency-declaration.html

Very High Greenhouse Gas Levels

Carbon Dioxide

On June 1, 2020, NOAA recorded a daily average carbon dioxide (CO₂) level of 418.32 ppm at Mauna Loa, Hawaii.

The image below shows hourly average CO₂ levels approaching 419 ppm at Mauna Loa on May 1, 2020.

The image below shows hourly (red circles) and daily (yellow circles) averaged CO₂ values at Mauna Loa, Hawaii over 31 days, up to May 31, 2020, with some recent hourly averages showing up with values exceeding 419 ppm.

The image below shows hourly (red circles) and daily (yellow circles) averaged CO₂ values at Mauna Loa, Hawaii over 31 days, through June 1, 2020, when a daily average of 418.32 ppm was recorded.

By comparison, the highest daily average CO₂ level recorded by NOAA in 2019 at Mauna Loa was 415.64 ppm, as discussed in an earlier post. The image below shows how CO₂ growth has increased over the decades.

As illustrated by the image below, the daily average CO₂ on June 1, 2019, was 414.14 ppm and the daily average CO₂ on June 1, 2020, was 418.32 ppm, i.e. 4.18 ppm higher. The average in May 2019 was 414.65 ppm and the average in May 2020 was 417.07 ppm, i.e. 2.42 ppm higher. Since the annual maximum is typically reached in May, this high reading for June 1, 2020, could indicate that, while CO₂ emissions by people were suppressed in April and May 2020 due to the COVID-19 lockdowns, growth of CO₂ levels in the atmosphere continues to speed up now as restrictions are relaxed.

Even more significant than the daily averages could be the hourly averages. The daily average CO₂ level recorded by scripps.ucsd.edu at Mauna Loa, Hawaii, was 418.04 ppm on May 25, 2020. On May 24, 2020, one hourly average exceeded 420 ppm, at which time emissions by people had raised CO₂ levels by some 160 ppm compared to the situation thousands of years ago, and by even more if levels had continued to follow a natural trend, as illustrated by the image and inset below.

A rise of 100 ppm CO₂ has historically corresponded with a global temperature rise of some 10°C or 18°F, when looking at CO₂ levels and temperatures over the past 420,000 years, as illustrated by the image below.

Concentrations of carbon dioxide, methane (CH₄) and nitrous oxide (N₂O) in 2018 surged by higher amounts than during the past decade, according to a 2019 WMO news release and as illustrated by the image on the right, from an earlier post, which shows that CH₄, CO₂ and N₂O levels in the atmosphere in 2018 were, respectively, 259%, 147% and 123% of their pre-industrial (before 1750) levels.

So, methane levels have been rising much faster than CO₂ since 1750 and there is much potential for an even faster rise in methane levels due to seafloor hydrate releases.

Furthermore, as industrial activity declines in the wake of COVID-19, loss of aerosol masking alone could trigger a rapid rise, as discussed by Guy McPherson in recent papers here and here.

Given this, the 160 ppm rise in CO₂ could lead to a global temperature rise of 18°C or 32.4°F from 1750, and such a rise could unfold soon, as oceans and ice take up ever less heat and further feedbacks kick in, as also discussed in earlier post such as this one and this one.

Levels for methane and nitrous oxide were very high in May 2020, as further discussed below.

Methane

MetOp-1 recorded peak methane levels of 2917 ppb at 469 mb on the afternoon of May 22, 2020.

MetOp-1 recorded mean methane levels of 1896 ppb at 336 mb on the morning of May 22, 2020.

MetOp-2 recorded peak methane levels of 1918 ppb at 586 mb on the afternoon of May 24, 2020.

Nitrous Oxide

N20 recorded peak nitrous oxide levels of 366 ppb at 840 mb on the morning of May 21, 2020.

N20 recorded somewhat lower peak nitrous oxide levels of 346.9 ppb at 487.2 mb on the afternoon of May 23, 2020, but look at how much of Antarctica is covered by the magenta color, reflecting levels at the top end of the scale.

Rising greenhouse gas levels are damaging the ozone layer

Nitrous oxide is both a potent greenhouse gas and an ozone depleting substance that is thus directly damaging the ozone layer.

Additionally, rising greenhouse gas levels are indirectly damaging the ozone layer in three ways:

Firstly, rising greenhouse gas levels are making water vapor enter the stratosphere. Higher sea surface temperatures along the path of the Gulf Stream fuel hurricanes traveling north along North America's east coast. More heat also translates into more wind; stronger hurricanes are getting stronger over the years.

Rising levels of greenhouse gases strengthen winds and increase water vapor in the atmosphere. Temperatures are rising faster in the Arctic than in the rest of the world, as illustrated by the image below, and this is changing the Jet Stream.

[ click on images to enlarge ]

Jennifer Francis has long pointed out that, as temperatures at the North Pole are rising faster than at the Equator, the Jet Stream is becoming wavier and can get stuck in a 'blocking pattern' for days, increasing the duration and intensity of extreme weather events. This can result in stronger storms moving more water vapor inland over the U.S., as discussed in earlier posts such as this one. Such storms can cause large amounts of water vapor to rise high up in the sky. Water vapor that enters the stratosphere can damage the ozone layer.

Secondly, as plumes above the anvils of severe storms bring water vapor up into the stratosphere, this also contributes to the formation of cirrus clouds that trap a lot of heat that would otherwise be radiated away, from Earth into space.

Thirdly, higher temperatures and stronger winds increase the intensity of droughts. Heatwaves combined with strong winds, dry soil and dry vegetation can make forest fires produce smoke that can enter the stratosphere and stay there for along time.

Recent examples of extreme weather events are described below, i.e. a huge storm and a heatwave in the Arctic.

Super Typhoon Amphan hits India and Bangladesh

Also in May 2020, super typhoon Amphan hit India and Bangladesh, with high waves and heavy rainfall. Waves as high as 14.2 m or 46.6 ft were forecast (at the green circle) for May 20, 2020, 06:00 UTC as Amphan approached Bangladesh.

"Once once-in-a-century, now once-in-a-decade", comments Sam Carana on this and other events.

The sea surface temperature image below shows that, on May 17, 2020, ocean temperatures were as high as 32.9°C or 91.1°F.

The combination image below shows high sea surface temperatures on May 15, 2020, 12:00 UTC, in the left panel.

Anomalies in the Indian Ocean were as high as 3.4°C or 6.0°F, in the Arctic Ocean as high as 1°C or 1.8°F and in the Pacific Ocean as high as 5.1°C or 9.1°F. Anomalies are from daily average during years 1981-2011.

The right panel of the combination image shows how these high ocean temperatures cause circular wind patterns. Wind speed was as high as 255 km/h or 159 mph in the Indian Ocean, at the location of super typhoon Amphan, on May 18, 2020, 06:00 UTC, while instantaneous wind power density was as high as 177.2 kW/m².

The combination image below shows the temporary cooling impact of Amphan.

The bottom panel shows that on May 18, 2020 09:00 UTC, the temperature at a location in India was 42.6°C or 108.6°F, as Amphan was approaching from the South.

The middle panel shows that, two days later, at the same location and at same time of day, the temperature had fallen to 23.4°C or 74°F as Amphan hit the area.

The cooling is only temporary. The top panel shows that a temperature of 47.9°C or 118.1°F is forecast for that location, same time of day, for May 26, 2020.

Siberian Heatwave

A heatwave hit Siberia in May 2020.

Above image shows that temperature anomalies were forecast to be at the high end of the scale over Siberia on May 22, 2020, 06:00 UTC, i.e. 30°C or 54°F higher than 1979-2000. At the same time, cold temperatures are forecast for much of eastern Europe.

What enables such a strong heatwave to develop is that the Jet Stream is getting more wavy as the temperature difference between the North Pole and the Equator is narrowing, causing both hot air to move up into the Arctic (red arrow) and cold air to descend out of the Arctic (blue arrow).

The Siberian heatwave threatens to trigger forest fires that can cause large amounts of black carbon to settle on the snow and ice cover, speeding up its demise. Furthermore, the heatwave threatens rivers to heat up that carry large amounts of water into the Arctic Ocean. Finally, as discussed, more intense forest fires threaten to cause organic carbon compounds to enter the stratosphere.

Extinction mechanism

A recent study by John Marshall et al. found that the Devionian mass extinction event 360 million years ago, that killed much of the Earth's plant and freshwater aquatic life, was caused by a brief breakdown of the ozone layer. John Marshall says: "Current estimates suggest we will reach similar global temperatures to those of 360 million years ago, with the possibility that a similar collapse of the ozone layer could occur again, exposing surface and shallow sea life to deadly radiation. This would move us from the current state of climate change, to a climate emergency."

John refers to the work by James Anderson et al., who warn that CO₂ and CH₄ release from clathrates and permafrost could cause more water to get carried into the stratosphere. John further describes the 'Extinction mechanism': "High summer temperatures over continental areas can increase the transport of water vapour high into the atmosphere. This water vapour carries with it organic carbon compounds that include chlorine, which are produced naturally by a wide variety of plants, algae and fungi. Once these compounds are near the ozone layer, they release the chlorine and this breaks down ozone molecules. This produces a positive feedback loop because a collapsing terrestrial ecosystem will release a flush of nutrients into the oceans, which can cause a rapid increase in algae."

Arctic sea ice volume

As Guy McPherson points out, COVID-19 alone could trigger an abrupt huge temperature rise.

Furthermore, loss of Arctic sea ice could cause a rapid temperature rise.

Ominously, Arctic sea ice volume has been at record low since the start of 2020, while 2019 volume was at a record low from October, making that volume has now been at record low for almost 8 months straight.

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


Links

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

• Climate Plan (June 1, 2019 version)
https://arctic-news.blogspot.com/2019/06/climate-plan.html

• The Keeling Curve - Scripps Institution of Oceanography at UC San Diego
https://scripps.ucsd.edu/programs/keelingcurve

• 417.93 parts per million (ppm) CO2 in air 24-May-2020
https://twitter.com/Keeling_curve/status/1264955470655025152

• Greenhouse Gas Levels Keep Accelerating
https://arctic-news.blogspot.com/2019/05/greenhouse-gas-levels-keep-accelerating.html

• Will COVID-19 Trigger Extinction of All Life on Earth? - by Guy McPherson
https://opastonline.com/wp-content/uploads/2020/04/will-covid-19-trigger-extinction-of-all-life-on-earth-eesrr-20-.pdf

• Earth is in the Midst of Abrupt, Irreversible Climate Change - by Guy McPherson
https://www.onlinescientificresearch.com/articles/earth-is-in-the-midst-of-abrupt-irreversible-climate-change.pdf

• 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

• Methane
https://arctic-news.blogspot.com/p/methane.html

• Study shows erosion of ozone layer responsible for mass extinction event
https://www.eurekalert.org/pub_releases/2020-05/uos-sse052620.php

• UV-B radiation was the Devonian-Carboniferous boundary terrestrial extinction kill mechanism - by John Marshall et al.
https://advances.sciencemag.org/content/6/22/eaba0768

• Prehistoric climate change damaged the ozone layer and led to a mass extinction - by John Marshall
https://theconversation.com/prehistoric-climate-change-damaged-the-ozone-layer-and-led-to-a-mass-extinction-139519

• UV Dosage Levels in Summer: Increased Risk of Ozone Loss from Convectively Injected Water Vapor - by James Anderson et al.
https://science.sciencemag.org/content/337/6096/835

• Care for the Ozone Layer
https://arctic-news.blogspot.com/2019/01/care-for-the-ozone-layer.html

• Why stronger winds over the North Atlantic are so dangerous
https://arctic-news.blogspot.com/2020/02/why-stronger-winds-over-north-atlantic-are-so-dangerous.html

• A Global Temperature Rise Of More than Ten Degrees Celsius By 2026?
https://arctic-news.blogspot.com/2016/07/a-global-temperature-rise-of-more-than-ten-degrees-celsius-by-2026.html

• Forces behind Superstorm Sandy
https://arctic-news.blogspot.com/2012/11/forces-behind-superstorm-sandy.html

• April 2020 temperatures very high
https://arctic-news.blogspot.com/2020/05/april-2020-temperatures-very-high.html

• Could Humans Go Extinct Within Years?
https://arctic-news.blogspot.com/2020/01/could-humans-go-extinct-within-years.html

• Arctic Ocean November 2019
https://arctic-news.blogspot.com/2019/11/arctic-ocean-november-2019.html

The Fatal Road To 4 Degrees Celsius

The fatal road to +4°Celsius

Extreme GHG and T°C rise rates exceed climate tipping thresholds

Andrew Glikson

Precis

Global CO₂ rise and warming rates have reached a large factor to an order of magnitude higher than those of the past geological and mass extinction events, with major implications for the shift in climate zones and the nature and speed of current extreme weather events. Given the abrupt change in state of the atmosphere-ocean-cryosphere-land system, accelerating since the mid-20ᵗʰ century, the terms climate change and global warming no longer reflect the nature of the climate extremes consequent on this shift. Further to NASA’s reported mean land-ocean temperature rise to +1.18°C for March 2020, relative to the 1951-1980 baseline, large parts of the continents, including Siberia, central Asia, Canada, parts of west Africa, eastern South America and Australia are warming toward mean temperatures of +2°C and higher. The rate exceeds that of the Last Glacial Termination (LGT) (21–8 kyr), the Paleocene-Eocene hyperthermal event (PETM) (55.9 Ma) and the Cretaceous-Tertiary boundary (K-T) (64.98 Ma) impact event. A principal question arises regarding the relationships between the warming rate and the nature and progression of the current migration climate zones toward the poles, including changes in the atmosphere and ocean current systems. Significant transient cooling pauses, or stadials, are projected as a consequence of the flow of cold ice melt water from Greenland and Antarctica into the oceans.

Figure 1. Global temperature distribution in March 2020, relative to a 1951-1980 baseline. NASA GISS.

The K-T impact and subsequent warming: According to Beerling et al. (2002) the CO₂ change triggered by the K-T impact event 65 Ma years ago involved a rise from about 400-500 ppm to 2300 ppm over 10.000 years from the impact (Fig. 2) at a rate of 0.18 ppm/year. This is less than the mean Anthropocene CO₂ rise rate of 0.415 ppm/year and an order of magnitude less than the 2 to 3 ppm/year rise rate in the 21ˢᵗ century. Likewise the Anthropocene temperature rise rate of ~ 0.0074°C/year is high by an order of magnitude as compared to the K-T impact event rate of~ 0.00075°C/year (Table 1) reported by Beerling et al. (2002).

Figure 2. Reconstructed atmospheric CO₂ variations during the Late Cretaceous–Early Tertiary derived from the SI
(Stomata index) of fossil leaf cuticles calibrated by using inverse regression and stomatal ratios. Beerling et al. (2002).

Beerling et al.’s (2002) estimate, based on fossil fern proxies, implies an initial injection of at least 6,400 GtCO₂  and possibly as high as 13,000 GtCO₂ into the atmosphere, significantly higher than values derived by Pope et al. (1997). This would increase climate forcing by +12 Wm⁻² and mean warming of ~7.5°C, which would have strongly stressed ecosystems already affected by cold temperatures and the blockage of sunlight during the impact winter and associated mass extinction at the KT boundary (O’Keefe et al. 1989).

The PETM hyperthermal event: The Palaeocene–Eocene Thermal Maximum, about 55.9 Ma, triggered the release of a large mass of light ¹³C-depleted carbon suggestive of an organic source, likely methane, has led to a global surface temperature rise of 5 – 9°C within a few thousand years (Table 1; Fig. 3). Deep-sea carbonate dissolution indices and stable carbon isotope composition were used to estimate the initial carbon pulse to a magnitude of 3,000 PgC or less. As a result, atmospheric carbon dioxide concentrations increased during the main event by up to 70% compared with pre-event levels, leading to a global surface temperatures rose by 5–9°C within a few thousand years.

Figure 3. Simulated atmospheric CO2 at and after the Palaeocene-Eocene boundary (after Zeebe et al. (2009).

The last glacial termination: Paleoclimate indices based on ice cores and isotopic evidence suggest temperature rise generally correlates with CO₂ during the Last Glacial Termination between 17.5 kyr to 10 kyr. Whereas the rise rates of CO₂ and temperature are broadly parallel the temperature somewhat lags behind CO₂ (Figure 2). Changes of CO₂ – 186 - 265 ppm and of temperature of T°C -3.3°C - +0.2°C (Fig. 4). A rise rate of ~0.010 ppm CO₂/year and of temperature ~0.00046°C/year are indicated (Table 1) (Shakun et al., 2012). Differences between temperature changes of the Northern Hemisphere and Southern Hemisphere correspond to variations in the strength of the Atlantic meridional overturning circulation.

Figure 4. Global CO₂ and temperature during the last glacial termination (After Shakun et al. 2012).
(LGM – Last Glacial Maximum; OD – Older Dryas; B-A - Bølling–Allerød; YD Younger Dryas).

Trajectories and rates of global CO₂ rise and warming

The rates at which atmospheric composition and climate changes occur constitute major control over the survival versus extinction of species. Based on paleo-proxy estimates of greenhouse gas levels and of mean temperatures, using oxygen and carbon isotopes, fossil plants, fossil organic matter, trace elements, the rate of CO₂ rise since ~1750 (Anthropocene) (CO₂ ᴀɴᴛʜ) exceeds that of the last glacial termination (CO₂ ʟɢᴛ) by an order of magnitude (CO₂ ᴀɴᴛʜ/CO₂ ʟɢᴛ = 41) and that of the Paleocene-Eocene Thermal Maximum (CO₂ ᴘᴇᴛᴍ) by a high factor (CO₂ ᴀɴᴛʜ/CO₂ ᴘᴇᴛᴍ ~ 3.8–6.9)(Table 1). The rise rate of mean global temperature exceeds that of the LGT and the PETM by a large factor to an order of magnitude (Table 1; Figs 5 and 6). It can be expected that such extreme rates of change will be manifest in real time by observed shifts in state of global and regional climates and the intensity and frequency of extreme weather events, including the following observations:

• A shift in climate zones (Fig. 7) including expansion of the tropics and migration of moderate mediterranean-type climate zones toward the poles , estimated at a rate of 56-111 km per decade (Thurton 2017), signifying a fundamental shift in state of the Earth’s climate regime.
• A high rate of ice melt and development of cool ocean pools south of Greenland and around Antarctica (Fig. 8a) developing into cool ocean regions and stadial climate conditions (Fig. 8b).
• Reduced temprature differences between the polar zones and mid-latitudes and thereby weakening of the polar boundaries and the polar jet stream boundary.
• Weakening of the North Atlantic Thermal Circulation.
• Changes in the southern ocean Antarctic oscillation and the Antarctic vortex.

The rapid increase in extreme weather events,including droughts, heat waves, fires, cyclones and storms.

Figure 5. Cenozoic and Anthropocene CO₂ and temperature rise rates.

Figure 6. 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 (1750–2019), and
(4) an asteroid impact. In the latter instance, temperature associated with
CO₂ rise would lag by some weeks or months behind aerosol-induced cooling.

Figure 7. An updated Köppen–Geiger climate zones map.

By contrast to linear IPCC climate projections for 2100-2300, climate modelling for the 21st century by Hansen et al. 2016 suggests major effects of ice melt water flow into the oceans from the ice sheets, leading to stadial cooling of parts of the oceans, changing the global temperature pattern from that of the early 21ˢᵗ century (Figs 8, 9a) to the late 21ˢᵗ century (Fig. 9b).

Figure 8. Global temperature patterns during El Nino and La Nina events. NASA GISS

Figure 9. a. An A1B model of surface-air temperature change for 2055-2060 relative
to 1880-1920 (+1 meters sea level rise) for modified forcing (Hansen et al. 2016);
b. A1B model surface-air temperatures in 2096 relative to 1880-1920 (+5 meters sea level rise) for 10 years
ice melt doubling time in the southern hemisphere and partial global cooling of -0.33°C (Hansen et al. 2016).

Summary and conclusions

1. Late 20th century to early 21asrt century global greenhouse gas levels and regional warming rates have reached a high factor to an order of magnitude faster than those of past geological and mass extinction events, with major implications for the nature and speed of extreme weather events.
2. The Anthropocene CO₂ rise and warming rates exceed that of the Last Glacial Termination (LGT) (21–8kyr), the Paleocene-Eocene hyperthermal event (PETM) (55.9 Ma) and the post-impact Cretaceous-Tertiary boundary (K-T) (64.98 Ma). 
3. Further to NASA’s reported mean land-ocean temperature rise of +1.18°C in March 2020, relative to the 1951-1980 baseline, large parts of the continents, including central Asia, west Africa eastern South America and Australia are warming toward mean temperatures of +2°C and higher. 
4. Major consequences of the current shift in state of the climate system pertain to the weakening of the polar boundaries and the migration of climate zones toward the poles. Transient cooling pauses are projected as a result of the flow of cold ice melt water from Greenland and Antarctica into the oceans, leading to stadial cooling intervals.
5. Given the abrupt shift in state of the atmosphere-ocean-cryosphere-land system, the current trend signifies an abrupt shift in state of the atmosphere, accelerating since the mid-20th century. Terms such as climate change and global warming no longer reflect the extreme nature of the climate events consequent on this shift, amounting to a climate catastrophe on a geological scale.

Andrew Glikson

Dr Andrew Glikson
Earth and Paleo-climate scientist
ANU Climate Science Institute

ANU Planetary Science Institute
Canberra, Australian Territory, Australiageospec@iinet.net.au

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 

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.