Arctic News: humidity

Showing posts with label humidity. Show all posts

Sunday, June 2, 2024

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

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)

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

Sunday, August 19, 2018

Will August 2018 be the hottest month on record?

July and August are typically about 3.6ºC or 6.5ºF warmer than December and January. August is typically 1.8°C or 3.24ºF warmer than the average annual temperature. Above image shows how much higher the temperature was for selected months, compared to the annual global mean for the period 1980-2015. Will August 2018 be the hottest month on record?

Numerous temperature records have fallen across the world recently. Heat stress hazard is high under conditions of high surface air temperature and high relative humidity. When looking at heat stress hazards, it's therefore important to look at surface air temperatures over land, i.e. the temperature of the air above the land surface.

Fire hazard is high under conditions of hot and dry soil and strong wind. When looking at fire hazards, it's therefore important to look at land surface temperatures, reflecting how hot the surface of the Earth would feel to touch in a particular location. The map below shows land surface temperatures.

When calculating how much warmer it is now, a number of things must be taken into account:

Baseline

What baseline is used and how is the temperature at the baseline calculated? In the image at the top, the baseline is 1980-2015, which is a very recent period. When using a preindustrial baseline, anomalies could be more than 0.6°C higher than when using the 1951-1980 baseline that NASA normally uses.
Surface temperatures or surface air temperatures?

Above map shows land surface temperatures. As said above, this is different from surface air temperatures over land that show the temperature of the air above the land surface.

Similarly, sea surface temperatures indicate the temperature of the water at the surface. Sea surface air temperatures, on the other hand, are slightly higher, they are measurements of the air temperature just above the surface of the water.

NASA typically uses surface air temperatures over land, while using surface water temperatures over oceans. When instead using air temperatures globally, the temperature anomaly could be more than 0.1°C higher.
Missing data

How are missing data dealt with? To calculate the global mean on maps, NASA uses four zonal regions (90-24ºS, 24-0ºS, 0-24ºN, and 24-90ºN) and fills gaps in a region by the mean over the available data in that region. In datasets, however, missing data are typically ignored. This could make a difference of 0.2°C. Ignoring data for the Arctic alone could make a difference of 0.1°C.

Depending on how the above three points are dealt with, the temperature in August 2018 may well be more than 3°C above the mean annual global temperature in 1750. The question is whether August 2018 will be warmer than August 2016, which was 2.3°C warmer than 1980-2015.

Anthropogenic Global Warming

Remember the Paris Agreement, when politicians pledged to take efforts to ensure that the temperature would not cross 1.5°C above pre-industrial? Why did the Paris Agreement not specify a year for pre-industrial? Perhaps the idea was that total anthropogenic global warming should not exceed 1.5°C. In other words, the warming that people had already caused by 1750, plus the warming people caused since 1750, plus the warming that is already baked in for the decades to come. The image below illustrates this idea and also shows that we're well above 1.5°C anthropogenic global warming.

In the image below, temperatures have also been adjusted to better reflect a preindustrial baseline (1750), showing that temperatures were not higher than 1°C above pre-industrial during the entire Holocene, until recently.

In a recent paper, James Hansen et al. conclude that temperatures also weren't more than 1°C above pre-industrial during the previous interglacial, the Eemian, which implies that temperatures haven't been more than 1°C above pre-industrial for the entire 200,000 years that modern people, i.e. the species homo sapiens, have existed, and that temperatures have only recently rising to levels more than 1°C above pre-industrial. Quite likely, to find temperatures as high as today's, one would have to go back some 3 million years.

Fires over North America, August 2018

Fires can significantly influence temperatures in a number of ways. The images below show how fires boosted carbon dioxide, carbon monoxide and sulfur dioxide levels on August 19, 2018. Carbon dioxide and carbon monoxide both raise temperatures. On the other hand, sulfur dioxide lowers temperature by reflecting sunlight back into space.

Top left: carbon monoxide as high as 51495 ppb

Top right: carbon dioxide as high as 836 ppm

Bottom left: Smoke over North America

Bottom right: sulfur dioxide as high as 1917.57 µg/m³

The image below illustrates to what extent smoke from fires boosted black carbon in the air over North America on August 23, 2018. Black carbon causes both cooling and warming. Black carbon shades the surface, somewhat cooling the surface of land and water, while it also absorbs heat, thus warming the air above the surface. Furthermore, black carbon causes warming by darkening the surface once it settles down. Studies have calculated that black carbon has a total net global warming effect of more than 1.1 W/m².

Dust and further aerosols

The impact of aerosols such as sulfur dioxide and dust is often overlooked. The image below shows that τ, i.e. light at 550 nm as a measurement of aerosol optical thickness due to dust aerosols, was as high as 4.0641 on June 16, 2018.

[ goats, from Wikipedia ]

Dust is one reason why temperatures didn't cross the 1°C above pre-industrial mark during the peak of the recent Milankovitch cycle. A recent study calculates that the global annual mean surface temperature increases by 0.3°C for the mid-Holocene (6 ka), if the dust is completely removed.

Most dust appears to originate from the Sahara Desert, which lost its vegetation during the Holocene due to goats, according to this study, as people removed predators such as lions and tigers. As the Sahara lost its vegetation, the surface became more reflective, while dust further made that temperatures didn't rise as much as they otherwise would have.

Deforestation has caused a lot of carbon dioxide to be added during pre-industrial times, and there is also the impact of black carbon aerosols, resulting from biomass and fossil fuel burning, which causes some 1.1W/m² warming today and some 0.2W/m² is coming from pre-industrial activities.

In conclusion, temperatures would be a lot lower in the absence of human activities, while total anthropogenic global warming over the past few thousand years is much larger than most people think.

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

Links

• NASA - The Northwest is Running Hot and Dry
https://earthobservatory.nasa.gov/images/92601/the-northwest-is-running-hot-and-dry

• NASA GISS (Goddard Institute for Space Studies) Surface Temperature Analysis (GISTEMP)
https://data.giss.nasa.gov/gistemp

• NASA - Just Another Day on Aerosol Earth
https://earthobservatory.nasa.gov/images/92654/just-another-day-on-aerosol-earth

• Aerosols
https://arctic-news.blogspot.com/p/aerosols.html

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

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

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

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

Friday, August 3, 2018

Peaks Matter

Heat stress

When calculating how much warmer we can expect it to get, climate models typically use linear projections based on temperature averages, such as annual global average temperatures, daily temperatures that are averages between day and night, etc. Sadly, this downplays the danger, as average temperatures are unlikely to kill people. When lives are at stake, peaks matter!

Where are temperatures rising most?

Temperatures are rising most strongly in the Arctic. Above map shows a rise of as much as 5.7°C or 10.26°F in Arctic.

Ocean heat on the move toward Arctic Ocean

The image below shows that the sea surface was 22°C or 71.6°F on August 13, 2018, at 77.958°N, 5.545°E (near Svalbard), i.e. 6.9°C or 12.4°F warmer than 47 days earlier and 16.4°C or 29.5°F warmer than it was during 1981-2011.

Local maximum temperatures can be good indicators for the maximum heat stress that can be expected in the area.

As illustrated by above image, the sea surface near Svalbard was 22°C or 71.6°F at the green circle on August 13, 2018, i.e. 16.4°C or 29.5°F warmer than 1981-2011.

This high sea surface temperature is an indicator of the temperature of the water below the surface, which in turn is an indicator of the amount of ocean heat that is entering the Arctic Ocean from the Atlantic Ocean.

Ocean heat is carried by the Gulf Stream from the North American coast toward the Arctic Ocean, as illustrated by the images below and on the right.

Warming of the Arctic Ocean comes with a number of feedbacks that accelerate this warming, such as albedo changes that take place as the Arctic snow and ice cover declines, and methane that is released from sediments containing methane in the form of hydrates and free gas.

The situation could get worse rapidly. As an example, with a decrease in cooling aerosols, which are concentrated in the Northern Hemisphere, the North Atlantic looks set to absorb more heat. A recent study calculated that the North Atlantic’s share of the uptake could increase from 6% to about 27%.

As another example, a recent study concludes: Existing models currently attribute about 20% of the permafrost carbon feedback this century to methane, with the rest due to carbon dioxide from terrestrial soils. By including thermokarst lakes, methane becomes the dominant driver, responsible for 70% to 80% of permafrost carbon-caused warming this century. Adding thermokarst methane to the models makes the feedback’s effect similar to that of land-use change, which is the second-largest source of manmade warming.

High methane levels warn about seafloor methane releases

The image on the right illustrates the danger, showing high methane levels at Barrow, Alaska, in July 2018.

When making projections of heat stress, it is important to look at all potential warming elements, including albedo changes, changes to jet streams and sea currents, higher levels of methane, high levels of water vapor, etc.

Methane is a potent greenhouse gas, causing huge warming immediately after entering the atmosphere, while this warming will be felt most strongly where the methane was released. Methane can therefore contribute strongly to local temperature peaks.

On August 6, 2018, mean global methane levels were as high as 1896 ppb. On August 8, 2018, they were as high as 1898 ppb.

Importantly, peak levels on the afternoon of August 6, 2018, were as high as 3046 ppb, as illustrated by the image on the right. The likely origin of those high levels is the Arctic Ocean, which should act as a stark warning of things to come.

Further contributors to heat stress

Next to temperature, humidity is of vital importance. A combination of high temperatures and high humidity is devastating.

A recent study shows that the risk of deadly heat waves is significantly increased because of intensive irrigation in specific regions. The study points at a relatively dry but highly fertile region, known as the North China Plain — a region whose role in that country is comparable to that of the Midwest in the U.S. That increased vulnerability to heat arises because the irrigation exposes more water to evaporation, leading to higher humidity in the air than would otherwise be present and exacerbating the physiological stresses of the temperature.

The image below shows a forecast of perceived temperatures in China on August 7, 2018.

The green circle highlights an area that is forecast to score high on the 'Misery Index' and that is centered around a location on the coast of Poyang Lake, which is connected to the Yangtze River. Temperatures there are forecast to be as high as 36.4°C or 97.4°F. At first glance, this may not look very high, but a relative humidity 68% is forecast to make it feel like 54.1°C or 129.3°F. This translates into a wet-bulb temperature of 31.03°C or 87.86°F.

The image on the right shows relative humidity. Also note the cyclones lined up on the Pacific Ocean. Cyclones can increase humidity, making conditions worse.

The high sea surface temperature anomalies that are common in the West Pacific (image right) contribute to warmer air and stronger cyclones carrying more moisture toward Asia, as discussed in this facebook thread which also features the next image on the right, showing that cyclone Soulik is forecast to cause waves as high as 18.54 m or 60.8 ft near Japan on August 20, 2018.

If humidity kept rising, a temperature of 36.4°C at a relative humidity of 91% would result in a wet-bulb temperature of 35°C. No amount of sweating, even in the shade and in front of strong winds or a fan, can cool the body under such conditions, and it would be lethal in a matter of hours in the absence of air conditioning or cold water.

There are further factors that can contribute to make specific areas virtually uninhabitable. The urban heat effect is such a factor. El Niño is another one. Land-only temperature anomalies are higher than anomalies that are averaged for land and oceans. As temperatures keep rising, heat waves can be expected to intensify, while their duration can be extended due to jet stream blocking.

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

Below, Paul Beckwith warns that parts of the world 'will soon be rendered uninhabitable'.

Regions to Soon Be Uninhabitable, From Unrelenting Heat and Humidity

Video: Unrelenting Heat, Humidity Will Soon Make Regions UNINHABITABLE

Paul Beckwith: "How hot can it actually get? What is in store for us? When you combine the heat domes sitting over many countries with high humidity, many areas around the planet will soon reach the deadly 35°C (95°F) 100% humidity (wet bulb temperature) or equivalent situation whereby a perfectly healthy person outside, in a well ventilated area, in the shade will die from the heat in 6 hours."

Video: Most Mammals Endure Heat Waves Better Than Humans

"Most people, like the very young, the elderly, and the rest of us won’t last anywhere as long, at even lower temperatures. I discuss the latest peer-reviewed science on how parts of high-risk regions in the North China Plains, Middle East, and South Asia will soon be rendered uninhabitable by combined heat and humidity."

Video: Uninhabitable Regions with Extreme Heat and Humidity

Also watch this video, in which Guy McPherson talks about the way aerosols currently mask the full wrath of global warming.

Video: Edge of Extinction: Rate Matters

Above video is also incorporated in the video below.

Video: McPherson's Paradox

and for the bigger picture, also watch the video below.

Video: Responding to Abrupt Climate Change with Guy R. McPherson

Links

• 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

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

• Latent Heat
https://arctic-news.blogspot.com/p/latent-heat.html

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

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

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

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

Tuesday, July 26, 2016

It could be unbearably hot in many places within a few years time

On July 24, 2016, 21:00 UTC, it was 98.7°F or 37.1°C at the green circle on above image. Because humidity at the time was 72% and wind speed was 2 mph or 3 km/h, it felt like it was 140.4°F or 60.2°C.

Above image shows temperatures, i.e. 98.7°F or 37.1°C at the green circle.

Above image shows that relative humidity was 72% at the green circle.

This event occurred at a location on the border of Missouri and Arkansas, just within Missouri, as is also indicated by the red marker above Google Maps image.

As the EPA animation on the right illustrates, a relatively small rise in average temperature can result in a lot more hot and extremely hot weather.

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 'Misery Index' is the perceived air temperature as a combination of wind chill and heat index (which combines air temperature and relative humidity, in shaded areas).

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 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.

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.

The above combination of 37.1°C at 72% relative humidity at a pressure of 1013 hPa translates into a wet-bulb temperature of 32.43°C. Had humidity risen to 87% while temperature remained at 37.1°C, the wet-bulb temperature would have risen above 35°C. Alternatively, had the temperature risen to 39.9°C while humidity remained at 72%, the wet-bulb temperature would also have risen above 35°C.

This goes to show how close the world is to unbearable heat. After all, this event occurred in Missouri, i.e. at some distance from the Equator, implying that, as temperatures and humidity levels keep rising, it could be unbearably hot in many places within a few years time.

As discussed in a recent post and illustrated by the image on the right, the world could be 10°C or 18°F warmer in ten years time. Accordingly, this would lead to numbers of climate-related global deaths in line with the prognosis below.