High feels like temperature forecast

Temperatures are forecast to reach 46.5°C or 115.8°F in Saudi Arabia (green circle left) and to reach 36.1°C or 96.9°F in China (green circle right) on August 4, 2024 06 UTC.

As illustrated by the image below, 'feels like' temperatures are forecast to reach 42.1°C or 107.9°F in Saudi Arabia (green circle left) and 53.6°C or 128.4°F at that location in China (green circle right), i.e. at Gaoyou, Yangzhou, Jiangsu, China, 325 km North of Shanghai, China, on August 4, 2024 06 UTC.

What makes the difference is that the 'feels like' temperature is the perceived air temperature as a combination of the heat index and wind chill. The heat index combines air temperature and relative humidity, in shaded areas. Relative humidity is forecast to be 7% in Saudi Arabia at the green circle left and 69% in China at the green circle right on August 4, 2024 06 UTC, as illustrated by the image below. 

The image below shows an even higher 'feels like' temperature of 55°C (130.9°F) that was recorded at a location 368 km north of Shanghai, China, on August 4, 2024, 09 UTC, caused by a combination of a temperature of 35.5°C (95.8°F) and a relative humidity of 75%, also resulting in a wet bulb temperature of 31.4°C (88.4°F). The image was made with a screenshot of current conditions (nowcast) at the time, but later readings show lower values (see image further below).

In hindsight, the highest 'feels like' temperature turned out to be 53.6°C (128.6°F), recorded at a location 361 km north of Shanghai, China, on August 4, 2024, 09 UTC, caused by a combination of a temperature of 35.6°C (96.2°F) and a relative humidity of 72%, also resulting in a wet bulb temperature of 31°C (87.7°F), as illustrated by the image below. 

The above image also shows wind at surface level, with a large circular wind pattern showing up south of Japan, which may have influenced conditions.  

An earlier post showed that a 'feels like' temperature of 54°C (129.1°F) hit an area west of Wuhan, China, on July 23, 2024.

High Wet Bulb Globe Temperature in California

Wet Bulb Globe Temperature takes into account the effect of temperature, relative humidity, wind speed, and solar radiation. Wet Bulb Globe Temperature is used by weather.gov to warn about extreme heat stress when in direct sunlight, as is forecast to occur in California in the grey areas on August 6, 2024 at 21 UTC. 

[ click on images to enlarge ]

The above image shows that a very high wet bulb global temperature is forecast for August 6, 2024, 21 UTC, at a location 7 miles west of Imperial, California, with the following details (inset):
- Temperature : 113°F or 45°C
- Apparent Temperature : 123°F or 51°C
- Wet Bulb Globe Temperature : 97°F or 36°C
- Dew Point : 69°F or 21°C
- Relative Humidity : 25%

Heat stress fatalities

Heat stress is the leading cause of weather-related deaths in the United States, as illustrated by the image below (credit: NOAA, text below from earlier post).

As the above image notes, the values for heat fatalities may be conservative. 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 study estimates that extreme heat accounted for 12,000 premature deaths in the contiguous U.S. from 2000 to 2010, and an analysis calculates that the summer 2022 heatwave killed 61,000 people in Europe alone.

Temperature thresholds

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.

As temperatures rise, high 'feels like' temperatures and high wet bulb globe temperatures can be expected to occur more and more. 

Wildlife, pets, livestock and vegetation also suffer at higher temperatures. A recent study finds thresholds where vegetation productivity experiences rapid suppression, with threshold crossings occurring first of all in tropical regions. The study adds that restricting global warming to just 1.5°C can increase safe areas for vegetation growth by 13% compared to allowing warming to reach 2°C above preindustrial levels. Crop failure, loss of vegetation (and benefits such as shade) and water shortages add to the predicament of high (and rising) temperatures.

Water vapor feedback

[ from Moistening Atmosphere ]

The water vapor feedback is one of numerous self-amplifying feedbacks that accelerate the temperature rise. Just the temperature rise itself will cause more water vapor to be present in the atmosphere. Rising temperatures will result in more water vapor in the atmosphere at a rate of 7% more water vapor for every 1°C warming, and this will further amplify the temperature rise, since water vapor is a potent greenhouse gas, as discussed at the extinction page.

The February 2024 temperature was 1.76°C above 1885-1915, which could be as much as 2.75°C above the pre-industrial temperature. A 2.75°C rise corresponds with almost ⅕ more water vapor in the atmosphere.

As illustrated by the image below, created with NOAA data, surface precipitable water reached a record high of 27.395 kg/m² in July 2024. 

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 are thresholds beyond which rising temperatures become lethal for humans, as discussed above.

Secondly, some species are more vulnerable than other species. As Gerardo Ceballos describes 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. sociopolitical 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 and politicians keep downplaying the dangers, there is 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.

High methane levels over Arctic Ocean

Humans will likely go extinct with a 3°C rise and one of the most-dreaded feedbacks that could contribute to such a rise is methane. Ominously, high methane levels are forecast over the Arctic Ocean for August 11, 2024, as illustrated by the image below, adapted from Copernicus. 

The above image shows a forecast for August 11, 2024, 00 UTC, at 850 hPa. High methane levels are present over the Arctic Ocean on the forecast. Note that the scale goes up to 24,840 parts per billion (ppb) for the dark red color. 

Ominously, high methane levels were also recorded recently at Barrow, Alaska. 

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

• Nullschool
https://earth.nullschool.net

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

• High Wet Bulb Globe Temperature Danger

https://arctic-news.blogspot.com/2024/07/high-wet-bulb-globe-temperature-danger.html

• Wet Bulb Globe Temperature Tipping Point
https://arctic-news.blogspot.com/2023/07/wet-bulb-globe-temperature-tipping-point.html

• Extreme heat stress
https://arctic-news.blogspot.com/2023/06/extreme-heat-stress.html

• Increased crossing of thermal stress thresholds of vegetation under global warming - by Xiangyi Li et al. 

https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.17406
Discussed at facebook at: 
https://www.facebook.com/groups/arcticnews/posts/10161596967289679

• Copernicus methane forecasts

https://atmosphere.copernicus.eu/charts/packages/cams/products/methane-forecasts

• 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

Have feedbacks taken over?

For about one year now, global temperature anomalies have been extremely high, as illustrated by the image below, created with a screenshot from Copernicus, showing an anomaly from 1991-2020 of 0.86°C on June 1, 2024.

What could be behind these persistently high temperatures? Many causes such as El Niño and sunspots have been discussed in earlier posts. How much do emissions contribute to these high temperatures?

Despite pledges by politicians to ensure that temperatures would not cross 1.5°C above pre-industrial, the growth rate of the concentration of carbon dioxide in the atmosphere appears to be accelerating, as illustrated by the image below, adapted from NOAA and showing concentration of carbon dioxide at Mauna Loa, Hawaii.

Have feedbacks taken over as the dominant driver of the temperature rise? The image below shows NOAA March 2009 through May 2024 monthly CO₂ concentration at Mauna Loa (black) with a trend (magenta) added for a joint 30-year coverage. The trend shows how CO₂ could cross the clouds tipping point at 1200 ppm (parts per million) in 2038, which in itself would push up temperatures by a further 8°C.

What could cause such a steep rise? Many studies point at organic carbon and inorganic carbon releases from soils that could further raise both CO₂ concentrations and temperatures. A recent study by Weiskopf (2024) finds that biodiversity declines from climate and land use change could lead to a global loss of up to 103.14 GtC for a global sustainability scenario and up to 145.95 GtC for a fossil-fueled development scenario, indicating a self-reinforcing feedback loop where higher levels of climate change lead to greater biodiversity loss, in turn leading to greater carbon emissions. 

The clouds tipping point is actually at 1200 ppm CO₂e (carbon dioxide equivalent), so it could be crossed even earlier when also taking into account more methane, nitrous oxide, etc. As discussed in an earlier post, the daily mean CO₂ on April 26, 2024, was 428.59 ppm, while peak daily average methane is approaching 2000 parts per billion (ppb) at Mauna Loa, Hawaii. A methane concentration of 2000 ppb corresponds, at a Global Warming Potential (GWP) of 200, with 400 ppm CO₂e. Together with the daily average CO₂ concentration of 428.63 ppm this adds up to a joint CO₂e of 828.63 ppm, i.e. only 371.37 ppm away from the clouds tipping point. 

This 371.37 ppm CO₂e could be added almost immediately by a burst of seafloor methane less than the size of the methane that is currently in the atmosphere (about 5 Gt). There is plenty of potential for such an abrupt release, given the rising ocean heat and the vast amounts of methane present in vulnerable sediments at the seafloor of the Arctic Ocean, as discussed in earlier posts such as this one and at the threat page.

There are many further developments and feedbacks that should be taken into account. Furthermore, note that anomalies in the image at the top are calculated from a 1991-2000 base. The temperature rise and the resulting feedbacks are even larger when anomalies are calculated from a pre-industrial base.

[ from earlier post ]

[ from Moistening Atmosphere ]

The above image, created with NASA content, shows that the February 2024 temperature was 1.76°C above 1885-1915, which could be as much as 2.75°C above pre-industrial (bright yellow inset right).

A 2.75°C rise corresponds with almost ⅕ more water vapor in the atmosphere, as the extinction page points out. The increase in water vapor in the atmosphere is a self-amplifying feedback, since water vapor is a powerful greenhouse gas, further accelerating the temperature rise.

Surface precipitable water reached a record high of 27.139 kg/m² in July 2023, as illustrated by the image below, adapted from NOAA.

[ from earlier post ]

Worryingly, data for the first four months of 2024 are way higher than they were in 2023 at the same time of year, which raises fears that surface precipitable water will reach an even higher peak in 2024 than was reached in 2023. The situation is depicted even more clearly on the image below, created with the same data.

As said, more water in the atmosphere further accelerates the temperature rise. Furthermore, high relative humidity also makes high temperatures more unbearable. The human body can cool itself by sweating, which has a physiological limit that was long described as a 35°C wet-bulb temperature, i.e. 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. 

A 2022 study (by Vecellio et al., 2022) finds that the actual limit is lower — about 31°C wet-bulb or 87°F at 100% relative 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, as discussed in an earlier post. 

Temperature in either °C or °F and the relative humidity for spots on Earth can be viewed at nullschool, and then the associated wet-bulb temperature can be calculated here.

North Atlantic

There are numerous tipping points and non-linear, self-amplifying feedbacks that can all contribute, interact and start to kick in with greater ferocity, amplifying and further accelerating the rise, as discussed at the feedbacks page. 

What could push up temperatures dramatically is loss of Arctic sea ice, as discussed in earlier posts such as this one. Ominously, the North Atlantic sea surface temperature anomaly has risen strongly recently, as illustrated by the images below. 

The maps below, adapted from Climate Reanalyzer, show sea surface temperatures (left) and sea surface temperature anomalies (right) on June 2, 2024. 

North Atlantic sea surface temperatures keep rising, as illustrated by the image below that highlights temperature anomalies from 1951-1980 for May 2022, May 2023 and May 2024. 

[ click on images to enlarge ]

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

• United Nations - Adoption of the Paris Agreement (2015)

https://unfccc.int/sites/default/files/english_paris_agreement.pdf

• NOAA - Global Monitoring Laboratory - Carbon Cycle Gases, Mauna Loa, Hawaii, U.S.
https://gml.noaa.gov/dv/iadv/graph.php?code=MLO&program=ccgg&type=ts

• NASA - datasets and images
https://data.giss.nasa.gov

• Climate Reanalyzer
https://climatereanalyzer.org

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

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

• Copernicus - Climate Pulse

https://pulse.climate.copernicus.eu

• NOAA - Physical Sciences Laboratory
https://psl.noaa.gov

• 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

• Biodiversity loss reduces global terrestrial carbon storage - by Sarah Weiskopf et al. (2024)  https://www.nature.com/articles/s41467-024-47872-7

Discussed at Facebook at: 
https://www.facebook.com/groups/arcticnews/posts/10161454674974679

• Very high temperatures in Tropics
https://arctic-news.blogshttps://arctic-news.blogspot.com/2023/07/wet-bulb-globe-temperature-tipping-point.htmlpot.com/2024/05/very-high-temperatures-in-tropics.html

• Extreme heat stress
https://arctic-news.blogspot.com/2023/06/extreme-heat-stress.html

• Wet Bulb Globe Temperature Tipping Point

https://arctic-news.blogspot.com/2023/07/wet-bulb-globe-temperature-tipping-point.html

• 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 facebook at:

https://www.facebook.com/groups/arcticnews/posts/10159973158374679

• Temperature rise may soon accelerate even more
https://arctic-news.blogspot.com/2024/05/temperature-rise-may-soon-accelerate-even-more.html

• nullschool

https://earth.nullschool.net

• wet bulb temperature calculator

https://www.mit.edu/~eltahirgroup/calTW.html

• Convert the temperature between Celsius and Fahrenheit

https://www.convert-me.com/en/convert/temperature/?u=dcelsius&v=40

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

• Jet Stream
https://arctic-news.blogspot.com/p/jet-stream.html

• Cold freshwater lid on North Atlantic
https://arctic-news.blogspot.com/p/cold-freshwater-lid-on-north-atlantic.html

• Arctic Ocean Feedbacks
https://arctic-news.blogspot.com/2017/01/arctic-ocean-feedbacks.html

• Arctic sea ice set for steep decline
https://arctic-news.blogspot.com/2024/03/arctic-sea-ice-set-for-steep-decline.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

  

High Wet Bulb Globe Temperatures hit the US again

Temperatures are high

Globally, temperatures have been at record high levels for the time of year for some time in 2023, as illustrated by the image below, adapted from Climate Reanalyzer. 

On August 25, 2023, the world temperature was 16.99°C, 0.94°C higher than it was on that day in 1979-2000. 

Extreme heat stress alert

High Wet Bulb Globe Temperatures hit the U.S. over a large area, over a long time. 

Wet Bulb Globe Temperatures were forecast to be as high as 95°F or 35°C in Lufkin, Texas, on Monday August 21, 2023 at 4 am Central Time.

Wet Bulb Globe Temperatures as high as 35°C were also forecast to be reached in Topeka, Kansas on the same day and at the same time, as illustrated by the image below.

The image below shows forecasts for August 24, 2023, measured as temperature (left), apparent temperature (center) and wet bulb globe temperature (right), three areas with high values marked by squares, circles, and stars, respectively.  

For descriptions of the various ways temperature can be measures, also see the earlier post Extreme Heat Stress. 

Unbearable conditions

The images further illustrate that, as temperatures rise, conditions are increasingly occurring that make it hard, if not impossible for many species (including humans) to survive, even at relatively high latitudes. This danger has been discussed in many earlier posts, such as in Humans may be extinct in 2026 and Two Tipping Points. 

In the video below, Guy McPherson gives his views on the situation.

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

• Climate Reanalyzer - Daily 2-meter Air Temperature
https://climatereanalyzer.org/clim/t2_daily

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

• Extreme Heat Stress
https://arctic-news.blogspot.com/2023/06/extreme-heat-stress.html

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

• Humans may be extinct in 2026

https://arctic-news.blogspot.com/2023/04/humans-may-be-extinct-in-2026.html

• Two Tipping Points

https://arctic-news.blogspot.com/2023/08/two-tipping-points.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

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) 

https://onlinelibrary.wiley.com/doi/abs/10.1111/ele.12144

• 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

Discussed at: https://www.facebook.com/groups/arcticnews/posts/10160004947844679

• Ten Dangers of Global Warming
https://arctic-news.blogspot.com/p/ten-dangers-of-global-warming.html

• Extreme heat stress

https://arctic-news.blogspot.com/2023/06/extreme-heat-stress.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

Extreme heat stress

Heatwaves

High Wet Bulb Globe Temperature (WBGT) is forecast to hit the Southeastern United States over the next few days. The image below shows a forecast for June 29, 2023, 18 UTC with WBGT as high as 34°C (93°F) forecast for a location near Jackson, Mississippi, U.S. 

[ click on images to enlarge ]

WBGT is a measure used by weather.gov to warn about expected heat stress when in direct sunlight. It estimates the effect of temperature, relative humidity, wind speed, and solar radiation on humans using a combination of temperatures from three thermometers:

• A Wet bulb measures the temperature read by a thermometer covered in a wet cloth. As water evaporates from the cloth, evaporation cools the thermometer. This mirrors how the human body cools itself with sweat.
• A black globe is used to measure solar radiation. Solar radiation heats the globe and wind blowing across it cools the globe.
• A Dry bulb calculates the air temperature measured in the shade. It is the temperature you would see on your thermometer outside.

The images on the right earlier featured in a 2016 post. 

The top image, an animation from the EPA, illustrates that a relatively small rise in average temperature can have a huge impact and result in a lot more hot weather as well as in even more extreme hot weather.

[ from earlier post ]

The three images underneath, from the IPCC, show the effect on extreme temperatures when (a) the mean temperature increases, (b) the variance increases, and (c) when both the mean and variance increase for a normal distribution of temperature.

The thermodynamic wet-bulb temperature is determined by temperature, humidity and pressure (hPa), and it is the lowest temperature that can be achieved by evaporative cooling of a water-wetted ventilated surface.

As temperatures and humidity levels keep rising, there comes a point 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 images below show high readings on the 'Misery Index', the perceived 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).

The image below shows a forecast for June 29, 2023 20 UTC, with weather conditions prolonged by circular wind patterns at 250 hPa (Jet Stream), while the Jet Stream is crossing the Equator (bottom left). Temperatures as high as 39.9°C (103.7°F) combined with a relative humidity of 35% result in perceived temperatures as high as 45°C (112.9°F) at the green circle.

As it turned out, the perceived temperature was as high as 44.9°C or 112.7°F on June 29, 2023 19 UTC, due to a 39.1°C or 102.5°F temperature and a 38% relative humidity at the surface, and with conditions prolonged by a distorted Jet Stream (at 250 hPa), with circular wind patterns and winds crossing the Equator.

The image below shows high readings on the 'Misery Index' for parts of Pakistan. On June 22, 2023, an air temperature of 45.4°C (113.7°F) and a relative humidity of 25% resulted in a perceived temperature of 51°C (123.7°F) at the area marked by the green circle. 

The above image also shows the Jet Stream (wind at 250 hPa). Distortion of the Jet Stream can lead to circular wind patterns that amplify heatwaves. As temperature rise, the temperature difference between the Equator and the Arctic narrows, distorting the Jet Stream resulting in more extreme  weather.

Perceived (feels like) air temperatures as high as 53.1°C or 127.7°F were recorded in Pakistan on July 4, 2023, 09 UTC (at green circle), with a 46.7°C or 116.1°F temperature and a 24% relative humidity recorded at the surface. Also, Jet Stream deformation shows up (at 250 hPa), with circular wind patterns and wind crossing the Equator (at the image bottom).

Meanwhile, heatwave conditions have also been affecting China, Texas and Mexico recently, with all-time high temperature records broken in each of these places. 

The press release of a 2022 Unicef report has the title 559 million children currently exposed to high heatwave frequency, rising to all 2.02 billion children globally by 2050. 

Fire and smoke from fires

An additional hazard is fire and the smoke from fires. The image below shows biomass-burning aerosols from fires in Canada extending over the North Atlantic on June 25, 2023, 03 UTC.

The forecast for June 29, 2023 21 UTC below shows remnants of the Canadian forest fires reaching Western Europe.

Feedbacks

As temperatures rise, fire and smoke hazards increase due to self-reinforcing feedback loops, including: 

• 

  [ Two out of numerous feedbacks ]

  Albedo loss and Jet Stream distortion:
  - as sea ice melts away and gets covered by meltpools and rainwater pools, soot, dust, and algae, the resulting albedo loss further pushes up temperatures
  - the narrowing temperature difference between the Arctic and the Tropics causes Jet Stream distortion, resulting in more extreme weather, incl. stronger storms that come with more lightning and can carry more oxygen to fires and spread fires faster and wider, and more intense heatwaves that can dramatically push up local temperatures, further intensifying droughts and forest fires
• a further self-reinforcing feedback loop is that water that was previously present in the soil, is increasingly moving up into the atmosphere, as the atmosphere sucks up more water vapor (7% more water vapor for every 1°C in temperature rise ), resulting in:
  - less evapotranspiration from vegetation, in turn resulting in less clouds and rain, thus pushing up temperatures and drying out soil and vegetation even more
  - erosion and less healthy vegetation that is more vulnerable to pests and diseases such as bark beetles, resulting in an increase in dead trees providing more fuel for fires

[ from earlier post ]

The image on the right, from a news release associated with a 2022 study, shows changes in atmospheric thirst, measured in terms of reference evapotranspiration from 1980-202 (in mm).

As temperatures rise due to people's emissions, more evaporation will take place over both land and oceans, but not all water will return as precipitation, so more water vapor will stay in the air and droughts affecting the soil and vegetation will intensify.

[ from earlier post ]

Water in the soil acts as a buffer, slowing down the temperature rise, so drier soil will heat up faster and further, causing land surface temperatures to rise even more and amplifying the impact of Urban heat island and Heat dome phenomena.

The image on the right, adapted from ESA, shows land surface temperatures as high as 65°C (149°F) in India on April 26, 2022. Note that land surface temperatures can be substantially higher than air temperatures.

The Copernicus image below shows Spain on 11 July 2023, where the Land Surface Temperature (LST), i.e. the temperature of the soil, in some areas of Extremadura (Spain) exceeded 60°C or 140°F, as measured by the Sea and Land Surface Temperature Radiometer (SLSTR) instrument, a feature of the Copernicus Sentinel-3 satellites. 

How high could temperatures rise?

The image below, from NASA, shows that February 2016 was 3.24°C or 5.83°F hotter on land than 1850-1890. Note that 1850-1890 is not pre-industrial, while the 2016 peak was reached during an El Niño, which raises the question how much hotter than pre-industrial it will be at the peak of the current El Niño. 

The image below says it even more poignantly: Looking at global averages over long periods is a diversion, peak temperature rise is the killer!

The above image shows that February 2016 was 3.28°C (5.904°F) hotter than 1880-1896 on land, and 3.68°C (6.624°F) hotter compared to February 1880 on land.

World temperature was at a new record high of 17.18°C or 62.92°F on July 4, 2023 (black). Both in 2022 (orange) and in 2016 (grey), the temperature reached 16.92°C or 62.46°F (on July 24, 2022 and August 13+14, 2016). The year 2016 is important, since it was a strong El Niño year and we're now again in an El Niño.

A 2023 study led by Tao Lian predicts the current El Niño to be strong. Moving from the bottom of a La Niña to the peak of a strong El Niño could make a difference of more than half a degree Celsius, as discussed in an earlier post.

Additionally, the June 2023 number of sunspots is more than twice as high as predicted, as illustrated by the image on the right, adapted from NOAA.

Furthermore, the 2022 Tonga submarine volcano eruption did add a huge amount of water vapor to the atmosphere, as discussed in an earlier post.

Alarm bells have been ringing for many years. As an example, the image below featured in a 2015 post, showing non-linear trends including a polynomial trendline (1: blue) pointing at global temperature anomalies of over 4°C by 2060. 

Moreover, a polynomial trend for the Arctic (2: red) threatens to cause major feedbacks to kick in, triggering runaway global warming (3: white) that looks set to catch up with accelerated warming in the Arctic and result in global temperature anomalies of 16°C by 2052.

[ from a 2015 post, click on image to enlarge ]

In the 2019 video below, Roger Hallam talks with Stephen Sackur from the BBC's HardTalk series. 

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.

Conclusion

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

[ image from Climate Emergency Declaration ]

Accordingly, everyone is encouraged to support and share this Climate Emergency Declaration.

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

• Nullschool.net
https://earth.nullschool.net

• Weather tracker: China issues heatstroke alert amid historic heatwave
https://www.theguardian.com/environment/2023/jun/23/weather-tracker-china-issues-heatstroke-alert-amid-historic-heatwave

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

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

• 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

• 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

• Jet Stream
https://arctic-news.blogspot.com/p/jet-stream.html

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

• Copernicus - Biomass-burning aerosols
https://atmosphere.copernicus.eu/charts/packages/cams/products/aerosol-forecasts

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

• Will there be Arctic sea ice left in September 2023?
https://arctic-news.blogspot.com/2023/05/will-there-be-arctic-sea-ice-left-in-september-2023.html

• Clausius–Clapeyron relation
https://en.wikipedia.org/wiki/Clausius–Clapeyron_relation

• Urban heat island
https://en.wikipedia.org/wiki/Urban_heat_island

• Heat dome
https://en.wikipedia.org/wiki/Heat_dome

• ESA - Heatwave across India
https://www.esa.int/ESA_Multimedia/Images/2022/04/Heatwave_across_India

• Evaporative Demand Increase Across Lower 48 Means Less Water Supplies, Drier Vegetation, and Higher Fire Risk
https://www.drought.gov/news/evaporative-demand-increase-across-lower-48-means-less-water-supplies

• A Multidataset Assessment of Climatic Drivers and Uncertainties of Recent Trends in Evaporative Demand across the Continental United States - by Christine Albano et al. (2022)

https://journals.ametsoc.org/view/journals/hydr/23/4/JHM-D-21-0163.1.xml

• Carbon dioxide crosses 422 ppm

https://arctic-news.blogspot.com/2022/04/carbon-dioxide-crosses-422-ppm.html

• 559 million children currently exposed to high heatwave frequency, rising to all 2.02 billion children globally by 2050

https://www.unicef.org/press-releases/heatwaves-report

• Copernicus - Scorching heatwave hits Spain 
https://www.copernicus.eu/en/media/image-day-gallery/scorching-heatwave-hits-spain

• NASA - custom plots 
https://data.giss.nasa.gov/gistemp/graphs_v4/customize.html

• Climate Reanalyzer - World Daily 2-meter Air Temperature (90-90°N, 0-360°E)
https://climatereanalyzer.org/clim/t2_daily

• NOAA - Solar cycle sunspot number progression
https://www.swpc.noaa.gov/products/solar-cycle-progression

• A Strong 2023/24 El Niño is Staged by Tropical Pacific Ocean Heat Content Buildup - by Tao Lian et al. (2023)

https://spj.science.org/doi/10.34133/olar.0011

• 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