Tuesday, August 15, 2023

Two Tipping Points

The image below, adapted from Climate Reanalyzer, shows that the World Sea Surface Temperature (60°South - 60°North) was at a record high of 21.1°C or 69.98°F for the third day in a row on August 23, 2023. As the image also shows, sea surface temperatures over the past few months have been much higher for the time of year than in any other year on record. 

The image below shows why this recent sea surface temperature rise is so worrying. The image below is based on NASA data for monthly mean global surface temperature anomalies (open ocean) vs 1901-1930. The ochre trend, based on January 1900-July 2023 data, indicates that the latent heat tipping point was crossed in 2021 and the seafloor methane tipping point may be crossed by the end of 2033. Both trends extend into the future for 15 years, but the red trend is based on July 2008-July 2023 data and better reflects El Niño and other variables, and this red trend indicates that the latent heat tipping point was crossed in 2023 and the seafloor methane tipping point may be crossed later this year.

[ click on images to enlarge ]

Sea ice constitutes a latent heat buffer, consuming incoming heat as it melts. While the ice is melting, all energy (at 334 J/g) goes into changing ice into water and the temperature remains at 0°C (273.15K or 32 °F). Once all ice has turned into water, all subsequent energy goes into heating up the water, and will do so at 4.18 J/g for every 1°C the temperature of the water rises. 

[ sea ice thickness, from earlier post ]
Loss of this buffer is linked to subsequent destabilization of methane hydrates. So, there are two tipping points that are linked, and the latent heat tipping point gets crossed in the Arctic before the seafloor methane tipping point gets reached.

The situation is particularly precarious in the Arctic, as the North Atlantic Ocean is very hot and the Gulf Stream keeps pushing hot water toward the Arctic Ocean, while Arctic sea ice has become very thin. The image on the right, from Uni of Bremen, shows that on July 25, 2023, there was virtually no Arctic sea ice left that was more than 30 cm thick. 

The latent heat tipping point is the point where Arctic sea ice loss is such that further incoming ocean heat that was previously consumed as Arctic sea ice melted, instead gets absorbed by the Arctic Ocean. 

[ sea surface temperature anomaly ]
The image on the right, adapted from nullschool.net, shows that on August 2, 2023, most of the Arctic Ocean was showing surface temperatures above the daily average during 1981-2011, indicating that the latent heat tipping point was reached. The latent heat tipping point is estimated to correspond with an ocean temperature anomaly of 1°C above the long term average, 1901-1930 on the above image.

The image underneath, also from nullschool.net, shows the situation on August 20, 2023, when temperatures at the North Pole had been above zero for more than a day and temperatures were forecast to go below zero only twice briefly afterwards, for the period up to August 24, 2023 19:00 UTC (which is as far as the forecast went at the time. 

[ surface temperature ]
This is a further indication that the latent heat tipping point has been reached and that no more heat can be consumed by sea ice melting.

How much sea ice is left? What does the sea ice look like, near the North Pole? Satellite images can give a good impression, but clouds can obscure the view. A clearer view can be obtained by comparing images over several days. 

An animation can reveal how much, or rather how little sea ice is left, and to what extent water of the Arctic Ocean is visible. 

[ Satellite view, click on images to enlarge ]
The animation on the right is made with four NASA Worldview images, showing the situation on August 11, 15, 16 and 19, 2023. 

The second tipping point, the seafloor methane tipping point, occurs as more heat reaches the seafloor where it destabilizes hydrates contained in sediments at the seafloor.

This tipping point comes with multiple self-reinforcing feedback loops, such as explosive growth in methane volume setting off further destabilization, rapid rise of Arctic temperatures, loss of permafrost and loss of albedo, and release of further greenhouse gases.

Crossing of the seafloor methane tipping point will occur later than crossing of the latent heat tipping point, so the seafloor methane tipping point is estimated to correspond with a higher ocean temperature anomaly.

The current situation is particularly precarious in the Arctic, as the North Atlantic Ocean is very hot and the Gulf Stream keeps pushing hot water toward the Arctic Ocean, while Arctic sea ice has become very thin (image right) and the latent heat tipping point has been crossed.

As the temperature of the Arctic Ocean keeps rising, more heat can reach sediments located at the seafloor, since much of the Arctic Ocean is very shallow and sediments at the seafloor of the Arctic Ocean can contain vast amounts of methane.

The danger is that further heat will destabilize hydrates in these sediments, leading to explosive eruptions of methane, as its volume increases 160 to 180-fold when leaving the hydrates, and resulting in huge eruptions of methane both from the destabilizing hydrates and from methane that is present in the form of free gas underneath the hydrates.

[ from earlier post, click on images to enlarge ]

The above image, from an earlier post, illustrates that warnings have been given before about the danger of these two tipping points getting crossed in the Arctic. In the above image, the trends are based on annual sea surface temperature data for the Northern Hemisphere. The seafloor methane tipping point is estimated to get crossed when the ocean temperature anomaly on the Northern Hemisphere goes beyond 1.35°C above its long term average.

The Argo Float 7900549 compilation image below illustrates that the highest water temperatures in the Arctic Ocean can occur at a depth of approximately 100 meters. The image shows temperatures as high as 5°C at that altitude.


Stronger winds along the path of the Gulf Stream can at times speed up sea currents that travel underneath the surface. As a result, huge amounts of hot, salty water can travel from the Atlantic Ocean into the Arctic Ocean, abruptly pushing up temperatures and salinity levels at the bottom of the Arctic Ocean, which in many places is very shallow.


The above image shows details of Argo float 9701007, further illustrating the danger that heat can reach the seafloor. North of Norway, where the water is less than 400 m deep, temperatures higher than 5°C show up throughout the vertical water column, up to August 10, 2023, when temperatures above 11°C were recorded close to the sea surface. The colored inset also shows that greater mixing down of heat occurred from October to December 2022, as the sea ice started to return and seal off the surface, preventing heat transfer from ocean to atmosphere, as also discussed at FAQ #11.

Below is another image adapted from Climate Reanalyzer, showing that the sea surface temperature of the North Atlantic Ocean has for months been much higher for the time of year than it was in previous years on record. Eight causes behind this have been discussed in an earlier post. The image below shows the situation on August 28, 2023, with the North Atlantic sea surface temperature reaching a record high of 25.34°C or 77.61°F. 


The image below, adapted from NOAA, shows how the Gulf Stream is pushing ocean heat toward the Arctic Ocean, while sea surface temperatures show up as high as 33.6°C or 92.48°F on August 17, 2023. 


[ 2022 animation ]
Studies, some of them dating back more than two decades, show that over the shallow East Siberian Arctic Shelf (ESAS) winds at times can mix the water column from the top to the bottom. A 2005 study of the ESAS led by Igor Semiletov recorded water temperatures at the seafloor, in September 2000, of 4.7°C at 20m depth at one location and 2.11°C at 41m depth at another location, with salinity levels of 29.7‰ and of 31.7‰, respectively.

A deformed Jet Stream, in combination with a cyclone, could similarly result in strong winds abruptly pushing a huge amount of heat through the Bering Strait into the Arctic Ocean. 

The animation on the right shows how remnants of Typhoon Merbok were forecast to enter the Arctic Ocean through the Bering Strait from September 17 to 19, 2022.

The image below, adapted from Climate Reanalyzer, shows that the (2-meter) air temperature in the Arctic was 3.79°C on August 25, 2023, a record high for the time of year and 2.08°C higher than the 1979-2011 mean for that day.


The image below illustrates how incoming ocean heat that previously was consumed in the process of melting of the sea ice, is now causing the water of the Arctic Ocean to heat up, with more heat reaching the seafloor of the Arctic Ocean, which has seas that in many places are very shallow.

[ Latent heat loss, feedback #14 on the Feedbacks page ]
Further adding to the danger is that destabilization of methane hydrates can cause huge amounts of methane to erupt with great force in the form of plumes. Consequently, little of the methane can be broken down in the water by microbes, while there is very little hydroxyl in the atmosphere over the Arctic Ocean to break down the methane that enters the atmosphere.

Ominously, some very high methane levels were recorded recently at Barrow, Alaska, as illustrated by the NOAA images below.

The most recent monthly methane average recorded at Barrow, Alaska, is above 2080 parts per billion.

In the video below, Guy McPherson describes the dire situation.


Climate Emergency Declaration

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.

The situation is dire and is getting more dire every day, which calls for a Climate Emergency Declaration and implementation of comprehensive and effective action, as described in the Climate Plan with an update at Transforming Society.


Links

• Climate Reanalyzer - daily sea surface temperature
https://climatereanalyzer.org/clim/sst_daily

• Climate Reanalyzer - daily 2-meter air temperature
https://climatereanalyzer.org/clim/t2_daily

• NASA - GISS Surface Temperature Analysis
https://earth.nullschool.net

• NOAA - Barrow Atmospheric Baseline Observatory, United States
https://gml.noaa.gov/dv/iadv/graph.php?code=BRW&program=ccgg&type=ts

• Argo Float
https://fleetmonitoring.euro-argo.eu

• Remnants of Typhoon Merbok forecast to enter the Arctic Ocean through the Bering Strait from September 17 to 19, 2022.
Discussed at https://www.facebook.com/SamCarana/posts/10166948876390161, from:
https://arctic-news.blogspot.com/p/cold-freshwater-lid-on-north-atlantic.html

• The East Siberian Sea as a transition zone between Pacific-derived waters and Arctic shelf waters - by Igor Semiletov et al. (2005)
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2005GL022490

• Sea surface temperature at record high
https://arctic-news.blogspot.com/2023/03/sea-surface-temperature-at-record-high.html

• Record high North Atlantic sea surface temperature



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Saturday, August 12, 2023

Return of the Blob?


The Blob is a large mass of water with relatively high heat content, floating at the surface and underneath the surface of the North Pacific Ocean. The Blob did appear several times before, including in 2016, which was a strong El Niño year. The above image shows high sea surface temperature anomalies in the North Pacific on August 10, 2023, raising the question of whether this constitutes a return of the Blob.

As temperatures rise, the Arctic is heating more rapidly than the rest of the world. The narrowing temperature difference between the Arctic and the Tropics is weakening the speed at which the jet stream circumnavigates Earth and this is making the jet stream more wavy.

In a 2012 study, Jennifer Francis et al. warned that this makes atmospheric blocking events in the Northern Hemisphere more likely, aggravating extreme weather events related to stagnant weather conditions, such as droughts, flooding and heatwaves. The Blob appears to be the marine version of a heatwave on land.

The image below shows that, on August 12, 2023, sea surface temperatures were as much as 7°C or 12.6°F higher than 1981-2011 in the Pacific Ocean (at the green circle, follow the arrow). A strongly deformed Jet Stream shows many circular wind patterns, prolonging, intensifying and increasing the occurrence of extreme weather events such as accumulation of heat during heatwaves. 


Is the Kuroshio Current slowing down?

The Kuroshio Current is an ocean current that carries heat along its path in the North Pacific, similar to the Gulf Stream in the North Atlantic Ocean. Is the Kuroshio Current slowing down as temperatures rise and is such slowing down causing hot water to accumulate in the western part of the North Pacific, leading to a return of a new Blob moving across the North Pacific toward the coast of North America?

The North Atlantic has been experiencing record high sea surface temperatures recently. A return of the Blob increases the danger of more heat reaching sediments at the seafloor of the Arctic Ocean.

[ 2022 animation ]
The animation on the right shows how remnants of Typhoon Merbok were forecast to enter the Arctic Ocean through the Bering Strait from September 17 to 19, 2022.

Studies, some of them dating back more than two decades, show that over the shallow East Siberian Arctic Shelf (ESAS) winds at times can mix the water column from the top to the bottom. A 2005 study of the ESAS led by Igor Semiletov recorded water temperatures at the seafloor, in September 2000, of 4.7°C at 20m depth at one location and 2.11°C at 41m depth at another location, with salinity levels of 29.7‰ and of 31.7‰, respectively.

A deformed Jet Stream, in combination with a cyclone, could result in strong winds abruptly pushing a huge amount of heat through the Bering Strait into the Arctic Ocean. This could cause methane hydrates to destabilize and huge amounts of methane to erupt from the seafloor and enter the atmosphere.

Conclusion

The situation is dire and is getting more dire every day, which calls for a Climate Emergency Declaration and implementation of comprehensive and effective action, as described in the Climate Plan with an update at Transforming Society.


Links

• The Blob

• Evidence Linking Arctic Amplification to Extreme Weather in Mid-Latitudes, by Jennifer Francis et al. (2012)
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2012GL051000 

• The Kuroshio current
https://en.wikipedia.org/wiki/Kuroshio_Current

• Record high North Atlantic sea surface temperature

• Remnants of Typhoon Merbok forecast to enter the Arctic Ocean through the Bering Strait from September 17 to 19, 2022.

• The East Siberian Sea as a transition zone between Pacific-derived waters and Arctic shelf waters - by Igor Semiletov et al. (2005)
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2005GL022490

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

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

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



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Wednesday, August 9, 2023

Arctic sea ice August 2023

Arctic Ocean heating up

There are at least five mechanisms that cause the water of the Arctic Ocean to heat up, as described below. 

1. Direct Heat. Heat from sunlight directly reaches the surface, i.e. the sea ice or the water of the Arctic Ocean.

The August 8, 2023, image on the right, from Climate Reanalyzer, shows a 1-3 days forecast of maximum surface temperatures (2m). Heatwaves over land can extend over the Arctic Ocean. 

High levels of emissions and greenhouse gases over the Arctic increase the amount of heat that is reaching the water of the Arctic Ocean and the sea ice. 

The NASA satellite image below shows smoke from forest fires in Canada moving over the Beaufort Sea and over the sea ice on August 6, 2023. 
[ click on images to enlarge ]

A recent study highlights that forest fires can strongly contribute to the temperature rise. Smoke, soot and further aerosols settling on the sea ice also darken the surface, resulting in more sunlight getting absorbed (feedback #9 on the feedbacks page). 

The image on the right, from a Copernicus news release dated August 3, 2023, shows the dramatic growth in emissions from fires in Canada up to end July 2023. 

The news release quotes Copernicus Atmosphere Monitoring Service senior scientist, Mark Parrington, who comments: "As fire emissions from boreal regions typically peak at the end of July and early August, the total is still likely to continue rising for some more weeks."

The Climate Reanalyzer image below shows that the temperature in the Arctic was at a record high for the time of year of 5.64°C or 42.15°F on August 9, 2023. Earlier, a record temperature of 5.81°C or 42.46°F was reached (on July 27, 2023).

Arctic sea ice typically reaches its minimum extent half September, when temperatures in the Arctic fall below 0°C and water at the surface of the Arctic Ocean starts refreezing.


2. Heat from Rivers. Hot water from rivers ending in the Arctic Ocean is another way the water is heating up and this is melting the sea ice from the side.

The August 10, 2023, image below, from nullschool.net, illustrates the added impact of heat that is carried by rivers into the Arctic Ocean, with sea surface temperatures as high as 20.4°C or 68.7°F recorded at a location where the Mackenzie River flows into the Arctic Ocean (at the green circle, where the green arrow is pointing at).


On August 6, 2023, the sea surface was 14.5°C or 26.2°F hotter than in 1981-2011, at a nearby location where the Mackenzie River is flowing into the Arctic Ocean, as illustrated by the image below.


The image on the right shows that on August 10, 2023, the sea surface temperature was 17.6°C or 63.7°F at a location where the Lena River in Siberia enters the Arctic Ocean, i.e. 14.2°C or 25.5°F hotter than it was in 1981-2011 (at green circle).

The Lena River flows into the Laptev Sea which is mostly less than 50 meters deep, making it relatively easy for surface heat to reach the seafloor. 

The NOAA image underneath on the right shows sea surface temperatures in the Bering Strait as high as 19.2°C or 66.56°F on August 8, 2023.

The image illustrates that the water can heat up strongly where hot water from rivers and run-off from rainwater enters the Bering Strait.

3. Ocean Heat. Yet another mechanism is heat that is entering the Arctic Ocean from other oceans, i.e. from the North Atlantic Ocean and the Pacific Ocean. Sea ice underneath the sea surface is melting from below due to ocean heat. 

An earlier post discusses why we are currently facing record high sea surface temperatures in the North Atlantic.

The image below shows how the Gulf Stream is pushing ocean heat toward the Arctic Ocean, while sea surface temperatures show up as high as 33.1°C or 91.58°F on August 9, 2023. 


The Gulf Stream is an ocean current that extends into the Arctic Ocean, as pictured below and discussed at this page. This ocean current is driven by the Coriolis force and by prevailing wind patterns.

[ from earlier post ]

This ocean current contributes to the stronger and accelerating rise in temperature in the Arctic (compared to the rest of the world), which in turn causes deformation of the Jet Stream that can at times cause strong winds that speed up this ocean current, as discussed in earlier post such as this 2017 one. 

[ from earlier post ]

4. Sea ice moving out. The Arctic Ocean is also heating up as sea ice is getting pushed into the Atlantic Ocean. Even the thickest sea ice can break up into pieces and move along with the flow of meltwater from glaciers, ocean currents and/or strong wind.

[ Click on images to enlarge ]
The animation below, created with NASA Worldview satellite images, shows the northern tip of Greenland at the top left of each frame. The green square on the image on the right indicates the area of the animation. It's around Prinsesse Thyra Island in Northeast Greenland National Park. 

This is where typically the thickest sea ice is located. The animation shows the sea ice breaking up and moving out of the Arctic Ocean. What is left of the pieces will eventually melt in the Atlantic Ocean. Pieces of sea ice that are pushed out of the Arctic Ocean reduce the latent heat buffer, as they can no longer consume heat in the Arctic Ocean through melting.  


5. Sea ice sealing off the Arctic Ocean from the atmosphere

The sea ice used to reach its lowest extent approximately half September. With the change in seasons, air temperatures decrease and sea ice starts increasing in extent at the sea surface. The image below illustrates how, as the Arctic Ocean starts freezing over, less heat will from then on be able to escape to the atmosphere. Sealed off from the atmosphere by sea ice, greater mixing of heat in the water will occur down to the seafloor of the Arctic Ocean, as discussed in FAQ#21.

[ From the post September 2015 Sea Surface Warmest On Record ]

In October, sea ice has stopped melting and is increasing in extent at the surface of the Arctic Ocean. Also, as land around the Arctic Ocean freezes over, less fresh water will flow from rivers into the Arctic Ocean, while hot, salty water will continue to flow into the Arctic Ocean. As a result, the salt content of the Arctic Ocean increases, all the way down to the seafloor of the Arctic Ocean, increasing the danger that ice in cracks and passages in sediments at the seafloor will melt, allowing methane contained in the sediment to escape and enter the atmosphere.

[ Pingos and conduits. Hovland et al. (2006) ]
Warmer water reaching these sediments can penetrate them by traveling down cracks and fractures in the sediments, and reach the hydrates. The image on the right, from a study by Hovland et al., shows that hydrates can exist at the end of conduits in the sediment. Such conduits were formed when some of the methane did escape from such hydrates in the past. Heat can travel down such conduits relatively fast and reach methane hydrates that keep methane in cages of ice. As heat reaches the ice cages, a temperature rise less than 1°C can suffice to destabilize such cages, resulting in a huge abrupt eruption, as the methane expands more than 160 times in volume.

[ The Buffer has gone, feedback #14 on the Feedbacks page ]
Further increasing the danger, this return of the sea ice results in less moisture evaporationg from the water, which together with the change of seasons results in lower hydroxyl levels at the higher latitudes of the Northern Hemisphere, in turn resulting in less methane getting broken down in the atmosphere over the Arctic.

Feedbacks and further developments

More generally, the rapid temperature rise threatens to cause numerous feedbacks to accelerate and further developments to occur such as crossing of tipping points, with the danger that the temperature will keep rising.

In the video below, Peter Carter, Paul Beckwith and Dale Walkonen discuss the situation.


One such feedbacks is the formation and growth of a cold freshwater lid at the surface of the North Atlantic that enables large amounts of salty and relatively hot water to flow underneath this lid and underneath the remaining sea ice, to enter the Arctic Ocean, as discussed earlier here, as well as here and at the feedbacks page.


This further increases the danger of destabilization of methane hydrates contained in sediments at the seafloor of the Arctic Ocean. 

Ominously, some very high methane levels were recorded recently at Barrow, Alaska, as illustrated by the NOAA image below.
Conclusion

The situation is dire and the outlook is getting more grim every day, calling for a Climate Emergency Declaration and implementation of comprehensive and effective action, as described in the Climate Plan and as most recently discussed at Transforming Society.


Links

• Climate Reanalyzer - Outlook Forecast Maps

• NASA - Worldview
https://worldview.earthdata.nasa.gov

• Shortwave absorption by wildfire smoke dominated by dark brown carbon - by Rajan Chakrabarty et al.
https://www.nature.com/articles/s41561-023-01237-9
discussed at: https://www.facebook.com/groups/arcticnews/posts/10160935394954679

• Feedbacks

• Climate Reanalyzer - Daily 2-meter Air Temperature

• NOAA - Sea Surface Temperature (SST) Contour Charts

• NOAA - Global Monitoring Laboratory - Barrow, Alaska

• Feedbacks in the Arctic

• Record high North Atlantic sea surface temperature

• NASA Worldview

• Copernicus news release - 2023 Canada wildfires emissions have already doubled previous annual record (August 3, 2023)
https://atmosphere.copernicus.eu/2023-canada-wildfires-emissions-have-already-doubled-previous-annual-record

• Warning of mass extinction of species, including humans, within one decade

• Cold freshwater lid on North Atlantic





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Sunday, August 6, 2023

Betrayal: The threat to life on Earth

by Andrew Glikson

It has been overlooked during Garma festival that, under current policies, global warming would render aboriginal lands in central and northern Australia unliveable and the top-end a nuclear target…

In his classic book The Fate of the Earth speaking for humanity Jonathan Schell describes the horror of a full-scale nuclear holocaust where human beings and animals would die if twenty thousand megatons of bombs, more than a million times the Hiroshima bomb, explode.

The consequences of a global nuclear exchange belong to the unthinkable. Nuclear weapons are the most destructive, inhumane and indiscriminate weapons ever created. Both on the scale of the devastation they cause and uniquely persistent genetically damaging radioactive fallout, they are unlike any other weapons. A single nuclear bomb detonated over a large city could kill millions of people. The use of tens or hundreds of nuclear bombs would disrupt the atmosphere world-wide, causing widespread famine.

[ Figure 1. Extreme geophysical, meteorological, hydrological and climatological events during 1980 -2012 ]

From the 1970s the full implications of climate change were only beginning to be realized, through a growing string of cyclones, fires, droughts and floods increasing in frequency and intensity above the recent historical record (Figure 1). At that time few could forecast the climate trajectory like NASA’s chief climate scientist (Hansen et al., 2012), who stated:

“Burning all the fossil fuels would create a different planet than the one that humanity knows. The paleoclimate 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” and “warming according to the IPCC Business As Usual’ (BAU) scenario would lead to a disastrous multi-meter sea level rise on the century timescale” and “We’ve reached a point where we have a crisis, an emergency, but people don’t know that” ...

[ Figure 2. credit: NOAA, click on images to enlarge ]

According to Hans Joachim Schellnhuber, Germany’s chief climate scientist “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” …

[ Figure 3. The five mass extinctions in the Earth’s history. ]

Within a century or less the Earth’s mean temperature has risen from the mean levels of the Holocene (the last 11,700 years) and the Pleistocene (11,700 years ago to 2.58 million years ago), to levels of the Pliocene (2.58 million years ago to 5.333 million years ago) to the Miocene (5.33 to 23.03 million years ago), 3 - 4°C warmer than the Holocene, at warming rates. This is faster than any identified in the Cenozoic (66 million years until the present) geological record (Glikson, 2022-23). It is difficult to find in the geological record an event increasing the global greenhouse level at a rate as extreme as the current global heating (Figure 4).

[ Figure 4. Past mean temperatures (200 AD to 2000 AD), current warming and future temperature projections (Steffen, 2012) ]

A nuclear war would represent the ultimate outcome of tribalism, nationalism, racism and war, the human propensity for mutual and self-destruction. There was a time when kings and generals would fall on their sword when they were defeated, or when their faith in their gods collapsed. Nowadays oblivious or non-caring world powers continue to proliferate nuclear weapons on hair trigger alert, mine coal and pump oil and gas, starting a greenhouse chain reaction. Leaders, so-called, opportunistically betray the defence of their own people and the future of their children. The voices of anti-nuclear and climate scientists have become subdued, ignored or betrayed. There may not be too many historians to document the 20-21ˢᵗ centuries crimes against humanity and against nature.

An explanation of the collapse of human society, dragging multiple species down with it, arises from Fermi’s Paradox, where the combination of technological achievements and an inherent killer instinct of some leads to collapse.


Andrew Glikson
A/Prof. Andrew Y Glikson
Earth and Paleo-climate scientist

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


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Monday, July 31, 2023

Wet Bulb Globe Temperature Tipping Point

High Wet Bulb Globe Temperatures (WBGT) are forecast to hit Louisiana, United States, over the next few days. The image below shows a forecast for August 2, 2023, 18 UTC, with WBGT as high as 35°C forecast for a location 10 miles South East of Abbeville, Louisiana, U.S.


WBGT is a measure used by weather.gov to warn about expected heat stress when in direct sunlight. It takes into account the effect of temperature, relative humidity, wind speed, and solar radiation on humans.

As temperatures and humidity levels keep rising, a tipping point can be reached where the wind factor no longer matters, in the sense that wind can no longer provide cooling. The human body can cool itself by sweating, which has a physiological limit that was long described as a 35°C wet-bulb temperature. Once the wet-bulb temperature reaches 35°C, one can no longer lose heat by perspiration, even in strong wind, but instead one will start gaining heat from the air beyond a wet-bulb temperature of 35°C.

Accordingly, a 35°C wet-bulb temperature (equal to 95°F at 100% humidity or 115°F at 50% humidity) was long seen as the theoretical limit, the maximum a human could endure.

A 2020 study (by Raymond et al.) warns that this limit could be regularly exceeded with a temperature rise of less than 2.5°C (compared to pre-industrial). 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.


A 2022 study (by Vecellio et al.) finds that the actual limit is lower — about 31°C wet-bulb or 87°F at 100% humidity — even for young, healthy subjects. The temperature for older populations, who are more vulnerable to heat, is likely even lower. In practice the limit will typically be lower and depending on circumstances could be as low as a wet-bulb temperature of 25°C.


The above image shows a Wet Bulb Globe Temperature of 35°C (95°F) forecast for August 11, 2023, 19 UTC, for a location near Baton Rouge, Louisiana, U.S. 


Heat is the leading cause of weather-related deaths in the United States, as illustrated by the above image (credit: NOAA). Heat fatalities may be conservative figures. Recent research finds that where heat is being listed as an official cause of death, this likely underestimates the full toll of these events. Extreme heat can trigger heart attacks and strokes. In addition, some heart disease risk factors, such as diabetes—as well as heart medications, such as diuretics and beta blockers—can affect a person’s ability to regulate their body temperature and make it difficult to handle extreme heat. The study finds that extreme heat accounted for about 600-700 additional deaths from cardiovascular disease annually. A recent study estimates that extreme heat accounted for 12,000 premature deaths in the contiguous U.S. from 2000 to 2010, and a recent analysis calculates that the summer 2022 heatwave killed 61,000 people in Europe alone. 

The image below shows a temperature (°F) forecast for August 1, 2023, from Climate Reanalyzer. 


The video below discusses this.


Misery Index

The image below show a high reading on the 'Misery Index', the perceived ('feels like') temperature that is used by nullschool.net, combining wind chill and the heat index (which in turn combines air temperature and relative humidity, in shaded areas). A Misery Index temperature of 56.1°C or 133.1°F was recorded at a location off the coast of the United Arab Emirates (green circle) on August 5, 2023.


The temperature at that location at the time was 35.2°C or 95.4°F, lower than the temperature on the land surrounding the Gulf, but the relative humidity at that spot over the water was 78%, and that combination led to this very high 'feels like' temperature. 

This constitutes a warning. The sea, rivers and lakes are traditionally seen as places to go to, to cool off. However, high temperatures combined with high humidity over water bodies can result in conditions that go beyond what humans can bear. 

Climate change danger assessment

The image below, earlier discussed here, expands risk assessment beyond its typical definition as the product of the severity of impact and probability of occurrence, by adding a third dimension: timescale, in particular imminence.




Imminence alone could make that the danger constituted by rising temperatures needs to be acted upon immediately, comprehensively and effectively. While questions may remain regarding probability, severity and timescale of the dangers associated with climate change, the precautionary principle should prevail and this should prompt for action, i.e. comprehensive and effective action to reduce damage and improve the situation is imperative and must be taken as soon as possible.

Rapidly rising temperatures constitute tipping points in several ways 

Firstly, there is a biological threshold beyond which rising temperatures become lethal for humans, as discussed above. 

Secondly, as Gerardo Ceballos describes in the video below and in a 2017 analysis, there is a biological tipping point that threatens annihilation of species via the ongoing sixth mass extinction. Researchers such as Gerardo Ceballos (2020), Kevin Burke (2018) and Ignation Quintero (2013) have for years warned that mammals and vertebrates cannot keep up with the rapid rise in temperature. Humans are classified as vertebrate mammals, indicating that we will not avoid the fate of extinction, Guy McPherson (2020) adds. 

Thirdly, there are further tipping points, e.g. social-political ones. On the one hand, it would be good if people became more aware, as this could prompt more people into supporting the necessary action. On the other hand, as temperatures keep rising, there is also a danger that panic will break out, dictators will grab power and civilization as we know it will collapse abruptly, as warned about earlier, e.g. in 2007.  



Conclusion

In conclusion, to combat rising temperatures, transforming society is needed urgently, along the lines of this 2022 post in combination with declaration of a climate emergency.


Links

• Wet Bulb Globe Temperature
https://digital.mdl.nws.noaa.gov

• National Weather Service - Wet Bulb Globe Temperature: How and when to use it
https://www.weather.gov/news/211009-WBGT

• The emergence of heat and humidity too severe for human tolerance - by Colin Raymons et al. (2020)
https://www.science.org/doi/10.1126/sciadv.aaw1838

• Brief periods of dangerous humid heat arrive decades early
https://www.climate.gov/news-features/featured-images/brief-periods-dangerous-humid-heat-arrive-decades-early

• Evaluating the 35°C wet-bulb temperature adaptability threshold for young, healthy subjects (PSU HEAT Project) - by Daniel Vecellio et al. (2022)
https://journals.physiology.org/doi/full/10.1152/japplphysiol.00738.2021
Discussed at: https://www.facebook.com/groups/arcticnews/posts/10159973158374679

• NOAA - Weather Fatalities 2022
https://www.weather.gov/hazstat

• The Effects of Heat Exposure on Human Mortality Throughout the United States - by Drew Shindell (2021)
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2019GH000234

• Heat-related mortality in Europe during the summer of 2022 - by Joan Ballester et al.
https://www.nature.com/articles/s41591-023-02419-z
Discussed at: https://www.facebook.com/groups/arcticnews/posts/10160875637104679

• As Temperatures Spike, So Do Deaths from Heart Disease (2022 News release)
https://www.acc.org/About-ACC/Press-Releases/2022/03/22/20/06/As-Temperatures-Spike-So-Do-Deaths-from-Heart-Disease

• Association of Extreme Heat and Cardiovascular Mortality in the United States: A County-Level Longitudinal Analysis From 2008 to 2017 - by Sameed Khatana et al. (2022)
https://www.ahajournals.org/doi/10.1161/CIRCULATIONAHA.122.060746

• Co-extinctions annihilate planetary life during extreme environmental change, by Giovanni Strona and Corey Bradshaw (2018)
https://www.nature.com/articles/s41598-018-35068-1
Discussed at: https://www.facebook.com/groups/arcticnews/posts/10156903792219679

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

• Climate Reanalyzer - Hourly Forecast Maps
https://climatereanalyzer.org/wx/fcst/?mdl_id=nam&dm_id=conus-lc&wm_id=t2

• PBS video - Too HOT and HUMID to Live: Extreme Wet Bulb Events are on the Rise 
https://www.pbs.org/video/too-hot-and-humid-to-live-extreme-wet-bulb-events-are-on-th-fazocs

• Nullschool
https://earth.nullschool.net

• How agriculture hastens species extinction | 60 Minutes (CBS News) | Gerardo Ceballos
https://www.youtube.com/watch?app=desktop&v=f21WWocqR-c

• Biological annihilation via the ongoing sixth mass extinction signaled by vertebrate population losses and declines - by Gerardo Ceballos, Paul R. Ehrlich and Rodolfo Dirzo (2017)
https://www.pnas.org/content/114/30/E6089

• Vertebrates on the brink as indicators of biological annihilation and the sixth mass extinction - by Gerardo Ceballos, Paul Ehrlich, and Peter Raven (2020)
https://www.pnas.org/content/early/2020/05/27/1922686117
Discussed at: https://www.facebook.com/groups/arcticnews/posts/10158460232764679

• Rates of projected climate change dramatically exceed past rates of climatic niche evolution among vertebrate species - by Ignatio Quintero et al. (2013) 

• Pliocene and Eocene provide best analogs for near-future climates - by Kevin Burke et al. (2018)
https://www.pnas.org/doi/10.1073/pnas.1809600115
Discussed at: https://www.facebook.com/groups/arcticnews/posts/10156972951354679

• Earth is in the Midst of Abrupt, Irreversible Climate Change - by Guy McPherson (2020)
https://www.onlinescientificresearch.com/articles/earth-is-in-the-midst-of-abrupt-irreversible-climate-change.pdf
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