Showing posts with label area. Show all posts
Showing posts with label area. Show all posts

Friday, August 7, 2026

Record high temperatures

Record high global surface air temperature for the time of year

On August 15, 2026, the global surface air temperature was 17.05°C, the highest temperature on record for this day of the year. The globe (inset) shows the global temperature anomaly vs 1991-2020 on August 15, 2026, with anomalies showing up higher than 12°C and with Antarctica and sea ice around Antarctica getting hit by very high (as well as low) temperature anomalies.


Record high Northern Hemisphere surface air temperature 

Land temperatures are rising faster than ocean temperatures. The Northern Hemisphere is heating up faster than the Southern Hemisphere, since the Northern Hemisphere has more land. On August 1, 2026, a record high temperature of 22.4°C was reached in the Northern Hemisphere, 1.45°C higher than 1979-2000, as illustrated by the image below. The globe (inset) shows temperature anomalies versus 1991-2020 on August 1, 2026, with the Northern Hemisphere highlighted.

[ click on images to enlarge ]

On August 12, 2026, the Northern Hemisphere temperature was 22.57°C, a record high for the day of the year and 1.48°C higher than 1979-2000, as illustrated by the image below. The globe (inset) shows temperature anomalies versus 1991-2020 on August 12, 2026, with the Northern Hemisphere highlighted.


The above anomalies are not calculated from pre-industrial. Another threshold is the wet-bulb temperature threshold, at which the human body can no longer cool down by sweating even in strong wind.

The image below shows a forecast for July 26, 2026, 21:00 UTC. The image shows a temperature of 122°F (50°C) at a location near Death Valley with a relative humidity of 9% resulting in a wet bulb globe temperature of 95°F (35°C). At the same time, a temperature of 116°F (47°C) with a relative humidity of 20% results in a wet bulb globe temperature of 97°F (36°C) at a location in the south of California.

[ Wet-bulb threshold crossed, image from earlier post ]
The wet-bulb globe temperature is measured in direct sunlight, whereas the wet-bulb temperature is measured in the shade. The wet-bulb temperature threshold can be reached or exceeded by a combination of temperature and humidity, and it is the maximum, the absolute physiological limit, that a human can endure as a peak. It was long assumed that reaching such a limit would require a large increase in global temperature. However, a 2020 study (led by Raymond) warns that this limit could be regularly exceeded with a temperature rise of less than 2.5°C above pre-industrial. As the above image indicates, the wet bulb globe temperature limit can already be reached or even exceeded now.

Furthermore, a 2022 study (led by Vecellio) finds that the actual limit can be much 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.

Record high sea surface temperature 

As illustrated by the image below, from an earlier post, the world (60°S–60°N, 0–360°E) sea surface temperature was 21.2°C on August 5, 2026, a record high temperature and 0.99°C higher than 1982-2010 (which is not pre-industrial). The globe (inset bottom left) shows sea surface temperature anomalies versus 1991-2020 on August 5, 2026.


Ocean heat is getting pushed along the path of the Gulf Stream from the North Atlantic through the Fram Strait into the Arctic Ocean and - to a lesser extent - from the North Pacific through the Bering Strait into the Arctic Ocean.

The image below shows sea surface temperature anomalies on August 19, 2026.  


On August 19, 2026, the sea surface temperature was 16.2°C (or 29.16°C) higher than 1981-2011 where water of the river Ob flows into the Arctic Ocean (green circle), as illustrated by the image below. 


The image below, adapted from NOAA, shows sea surface temperatures as high as 33.6°C (or 92.48°F) around North America on August 17, 2026. The image also illustrates geographic conditions facilitating the Gulf Stream to push ocean heat north in the Atlantic Ocean toward the Arctic.

[ Sea surface temperatures as high as 33.6°C on August 17, 2026 - click on images to enlarge ]

The image on the right shows a surface temperature of 23.1°C or 73.5°F recorded at a location on Greenland marked by the green circle on August 5, 2026.

As air temperatures and sea surface temperatures rise at higher latitudes, the danger increases that a huge amount of warm, salty water suddenly gets pushed into the Arctic Ocean by a cyclone, destabilizing sediments at the seafloor and triggering eruptions of methane from hydrates.

This danger has been discussed in many earlier posts such as this 2018 post.

The combination image below shows a nullschool.net image with a sea surface temperature of 4.6°C or 40.3°F recorded at the green circle on August 8, 2026 (left), and Northern Hemisphere maximum temperature on August 9, 2026 (right).


Sea ice 

Rising temperatures threaten to unleash a Double Blue Ocean Event. 

The combination image below shows Arctic sea ice concentration on August 8, 2026 (left), and Arctic sea ice thickness on August 8, 2026 (right). 


The high temperatures that are recorded in many places in August 2026 are not restricted to the Northern Hemisphere. The image below shows that a temperature of 42°C or 107.6°F is forecast to hit a location in Paraguay (marked by the green circle) while it is winter in the Southern Hemisphere, on August 17, 2026.


On August 13, 2026, the global sea ice area was 15.56 million km², the second lowest on record for that day and a deviation of -5.07σ, as illustrated by the image below. The year 2026 is highlighted in black, the year 2025 is highlighted in blue and the years 2023 and 2024 are highlighted in purple. 


The combination image below shows Antarctic sea ice concentration on August 12, 2026. The image on the right also shows the median ice edge 1981-2010. 


On August 13, 2026, Antarctic sea ice area was 2 million km² lower than 1981-2010, the second lowest on record for that day and a deviation of -4.44σ, as illustrated by the image below. The year 2026 is highlighted in black, the year 2023 is highlighted in blue and the year 2016 is highlighted in purple. 


Both 2016 and 2023 were strong El Niño years and the 2026 El Niño is on track to become even stronger, as discussed below. 

El Niño

The image below, from NOAA, shows an outlook of the 2026 El Niño strength and probabilities, issued August 2026.


The image below shows that the sea surface temperature in the Nino3.4 region was 29.65°C on August 9, 2026, 2.87°C higher than 1982-2010 and a jump of 3.9°C in a span of 7 months from the 25.75°C recorded on January 9, 2026. The globe (inset bottom) shows sea surface temperature anomalies versus 1991-2020 on August 9, 2026 with the Nino3.4 region highlighted in the Pacific Ocean.


Back in March 2026, La Niña was dominant, but this time what is forecast to be the strongest El Niño on record is present and it is strengthening, with the potential to unleash a Double Blue Ocean Event, an Arctic Blue Ocean Event in 2026 followed by an Antarctic Blue Ocean Event in early 2027.


The above image is adapted from Climate Reanalyzer and shows sea surface temperature anomalies versus 1951-1980 over the years in the Niño3.4 region, a region in the Pacific Ocean that is indicative for El Niño strength. The image has a potential 2026 El Niño anomaly of more than 3.5°C added (red dashed line on the right) to highlight the danger that a Double Blue Ocean Event will occur. For more on the 2026 El Niño also see this earlier post. 


The above image shows the global monthly temperature anomaly versus 1951-1980 through July 2026. 


The above image shows the July 2026 temperature anomaly versus 1951-1980, with very high anomalies showing up over and around Antarctica. 

[ click on images to enlarge, image from earlier post ]
The above image, from Berkeley Earth Temperature Report for 2024, illustrates the importance of Antarctic Sea ice loss in accelerating the temperature rise in 2020-2023 compared to 2010-2019. The red color shows an area with an extra radiative forcing of +2.1 W/m², which is primarily the result of Antarctic sea ice loss. This +2.1 W/m² is about as much as forcing as the change caused by all CO² released by people from 1750 to 2019, according to IPCC AR6 figures (image right, from earlier post).

Antarctic sea ice area was only 1.09 million km² on February 22, 2023, very close to the 1 million km² threshold when a Blue Ocean Event could be called, as illustrated by the image on the right, from an earlier post.

El Niño could trigger huge rise

Land temperatures are rising faster than ocean temperatures. The image below shows NASA Land-Only annual anomalies versus 1880-1890 (not pre-industrial) through 2025. 


The above image shows that 1.5°C was crossed on land for each month since 2009 (black squares). The Lowess 3-year smoothing trend (red line) indicates that 2°C was crossed on land in 2021 and that 3°C may get crossed on land soon, possibly before 2030 if this trend continues (dashed red extension), or even as early as end 2026, triggered by El Niño (see image below).

As said, land temperatures are rising faster than ocean temperatures. The Northern Hemisphere is heating up faster than the Southern Hemisphere, since the Northern Hemisphere has more land. The image below shows NOAA temperature anomalies versus 1901-2000 (not pre-industrial) on land in the Northern Hemisphere through July 2026 with a polynomial trend added. The image should act as a warning, illustrating the danger that the strengthening 2026 El Niño could trigger a rapid and steep rise in temperature on land in the Northern Hemisphere in late 2026 that could cross the 3°C threshold.


Human extinction

Most people live on land in the Northern Hemisphere. A 2019 post discussed a 2018 study (by Strona & Bradshaw) indicating that most life on Earth will disappear with a 5°C rise. What does this mean for humans? Terrestrial vertebrates are more in danger than many other species, since they depend on numerous other species for food. Humans are terrestrial vertebrates and humans are also large warm-blooded mammals with high metabolic rates, thus requiring more habitat. It also takes a long time for humans to reach maturity. Additionally, humans have become addicted to processed food, fossil fuels, plastic, etc. Furthermore, humans require large amounts of fresh water, including for sweating when temperatures rise. Therefore, a temperature rise of more than 3°C may be fatal for many species such as humans. In other words, a 3°C rise may suffice to cause human extinction, as warned about in earlier posts such as this one. The image below highlights the existential danger for humans.
As temperatures rise, the outlook is widespread crop loss and shortages of fresh water. Temperatures are rising too fast for forests to adapt by moving to higher latitudes. It takes centuries for tree populations to adapt—far too slow to keep pace with today’s rapid warming. Merely planting trees may not help much if the soil lacks ectomycorrhizal fungi, as discussed in an earlier post. Rapidly transforming society could improve the outlook, but - sadly - this currently doesn't have much government support.

Conclusion

The situation is dire and unacceptably dangerous, and the precautionary principle necessitates the danger to be acknowledged, while facilitating rapid, comprehensive and effective action to reduce the damage and to improve the outlook, where needed in combination with a Climate Emergency Declaration, as described in posts such as in this 2022 post and this 2025 post, and as discussed in the Climate Plan group.


Links

• Climate Reanalyzer
https://climatereanalyzer.org

• NASA - Goddard Institute for Space Studies
https://data.giss.nasa.gov/gistemp

• NOAA - Sea Surface Temperature Contour Charts
https://www.ospo.noaa.gov/products/ocean/sst/contour/index.html

• NOAA - ENSO strength probabiliities
https://cpc.ncep.noaa.gov/products/analysis_monitoring/enso/roni/strengths

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

• NSIDC - National Snow and Ice Data Center
https://www.nsidc.org

• Rising temperature threatens to devastate sea ice 


• Double Blue Ocean Event

• Double Blue Ocean Event 2026-2027? - update

• Antarctica


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Saturday, October 25, 2025

Antarctic sea ice area reaches record daily low

Antarctic sea ice area remained at a record daily low on October 24, 2025, following a record daily low on October 23, 2025. Antarctic sea ice area was 12.40 million km² on October 24, 2025, a deviation from 1981-2010 of -3.57σ, as illustrated by the image below.

The above image also shows that Antarctic sea ice reached a record low area of 1.09 million km² on February 24, 2023, close to a Blue Ocean Event and corresponding with a deviation of -2.86σ, i.e. smaller than the deviation of -3.57σ reached recently (on October 23, 2025).

Global sea ice extent

Low sea ice extent means that less sunlight gets reflected back into space and instead gets absorbed by the sea surface, resulting in high sea surface temperatures. Currently, sea ice is low at both poles. The low global sea ice extent at this time of year spells bad news for Antarctic sea ice, which typically reaches its minimum extent in February. 

The image below shows that the standard deviation from 1981-2010 of the global sea ice extent was -6.89σ on October 31, 2025, which is remarkable given the absence of El Niño conditions in 2025. 


Arctic sea ice volume

Meanwhile, Arctic sea ice volume remains at a record daily low, as it has been for more than a year. The image below shows Arctic sea ice volume through October 31, 2025.


High temperatures

Low sea ice and polar amplification of the temperature rise contribute to high air temperatures at both poles. The image below shows the September 2025 temperature anomaly compared to 1951-1980.

[ from earlier post ]
The low sea ice and the high temperatures are even more remarkable given the absence of El Niño conditions.

[ click on images to enlarge ]
Little sunlight is yet reaching the South Pole at this time of year. While temperatures over Antarctica are still well below zero °C, they are rising fast. Antarctic temperature anomalies were high in September 2025 (see the above image) and in October 2025 (see the image below). 

The image on the right, adapted from NOAA, shows the ENSO outlook (CFSv2 ensemble mean, black dashed line) favors La Niña persisting into the early Northern Hemisphere winter 2025-26. 

[ image from earlier post ]
The image on the right, adapted from ECMWF, shows the ENSO anomaly and forecast for developments in Niño3.4 through August 2026, indicating that the next El Niño will emerge and grow in strength in the course of 2026.  

A record high daily Antarctic temperature was reached on October 26, 2025, corresponding with a temperature anomaly of +5.08°C versus 1979-2000, as illustrated by the image below. 

The inset on the image below shows high temperature anomalies at both poles vs 1991-2020 on October 26, 2025. 


A record high daily Arctic temperature was reached on October 27, 2025, corresponding with a temperature anomaly of +5.99°C versus 1979-2000, as illustrated by the image below. The inset on the image below shows high temperature anomalies at both poles vs 1991-2020 on October 27, 2025. 

Global temperature anomalies have been rising over the past few months, and reached a record daily high of 15.04°C, an anomaly of +0.93°C versus 1991-2020, on October 25, 2025, as illustrated by the image below.

The following day, on October 26, 2025, the temperature reached another daily high. The image below shows temperature anomalies in red from January 1, 2023, through October 26, 2025, with a non-linear (polynomial) trend added in blue. 


Note that the anomalies on the above images are calculated from 1991-2020. When calculated from pre-industrial, the anomalies will be much higher, as discussed in earlier post such as this one. 

The image below shows a forecast of the temperature anomaly vs 1981-2010 for November 2025. 


The image below shows a forecast of the temperature anomaly versus 1981-2010 for December 2025. 


The situation is dire. An Antarctic Blue Ocean Event (sea ice approaching a low of one million km²) threatens to occur in February 2026, triggering an Arctic Blue Ocean Event later in 2026 while the next El Niño is strengthening, which comes with a huge danger of massive amounts of methane erupting from the seafloor. 

Southern Ocean sea surface getting more salty

High temperature anomalies are present at both the poles, as illustrated by the image below that shows the situation on October 25, 2025. 


High temperatures come with Jet Stream distortion on October 25, 2025, as illustrated by the image below that shows the Jet Stream (at 500 hPa) moving deep over Antarctica. 


This came with high precipitable water anomalies over Antarctica, as illustrated by the image below. 


This came with snowfall over Antarctica, as illustrated by the image below. 


The danger has been discussed in earlier posts such as this one. The increased snowfall thickens the snow on Antarctica with only little freshwater returning to the ocean. As a result, the Southern Ocean surface is getting more salty, and as also discussed in an earlier post, saltier surface waters sink more readily, allowing heat from the deep to rise, which can melt Antarctic sea ice from below, even during winter, making it harder for ice to reform. This vertical circulation also draws up more salt from deeper layers, reinforcing the cycle.

This leads to a loss of sea ice (and thus loss of albedo and latent heat buffer), as well as less heat getting transferred from the atmosphere into the Southern ocean, while more heat can be transferred from the Southern Ocean to the atmosphere. 

The methane danger

The methane danger is illustrated by the image below, adapted from an image issued by NOAA October 29, 2025, showing hourly methane averages recorded at the Barrow Atmospheric Baseline Observatory (BRW), a NOAA facility located near Utqiaġvik (formerly Barrow), Alaska, at 71.32 degrees North. 


Danger assessment

A state of emergency is typically declared after a disaster hits a specific area. The idea is that repairs or replacement of buildings, equipment and infrastructure can quickly restore the situation to what it previously was. Insurance companies have traditionally determined premiums for insurance policies by calculating the risk of events by their severity and probability.   

However, extreme weather events can increasingly be expected to occur more frequently and important considerations are the intensity and severity at which one specific place gets hit by an event, as well as ubiquity and imminence of such events. As temperatures rise, more extreme weather events can be expected to occur with greater intensity, more frequently, over larger areas, with longer duration and to become more ubiquitous and follow each other up with increasing if not accelerating rapidity.


As the likeliness of a huge and accelerating temperature rise, the severity of its impact, and the ubiquity and the imminence with which it will strike all become more manifest—the more sobering it is to realize that a mere 3°C rise may suffice to cause human extinction.

Climate Emergency Declaration

UN secretary-general António Guterres recently spoke about the need for “a credible global response plan to get us on track” regarding the international goal of limiting the global temperature rise. “The science demands action, the law commands it,” Guterres said, in reference to a recent international court of justice ruling. “The economics compel it and people are calling for it.”

What could be added is that the situation is dire and unacceptably dangerous, and the precautionary principle necessitates rapid, comprehensive and effective action to reduce the damage and to improve the outlook, where needed in combination with a Climate Emergency Declaration, as described in posts such as this 2022 post and this one and as discussed in the Climate Plan group.



Links

• Kevin Pluck - Sea ice visuals
https://seaice.visuals.earth

• Climate Reanalyzer
https://www.climatereanalyzer.org

• Danish Meteorological Institute - Arctic sea ice thickness and volume 
https://ocean.dmi.dk/arctic/icethickness/thk.uk.php

• Copernicus
https://pulse.climate.copernicus.eu

• Tropicaltidbits
https://www.tropicaltidbits.com




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Friday, September 19, 2025

Double Blue Ocean Event 2026? (update)

Arctic sea ice looks set to continue to be at record low daily volume, as it has been for more than a year. The image below shows Arctic sea ice volume through September 22, 2025. 

While Arctic sea ice volume continues to be at record daily low levels, its decline since its maximum in April through to its minimum in September has been relatively slim this year, which can be the result of natural variability (including of wind patterns), of an increase of freshwater and of slowing down of AMOC (as also discussed in comments on facebook). 

At the same time, sea surface temperatures have kept rising, with huge amounts of ocean heat accumulating at higher latitudes north recently, as illustrated by the image below that shows sea surface temperature anomalies at 30°N-90°N. 

[ image from earlier post, click to enlarge ]

High (and rising) greenhouse gas concentrations combined with a decrease in aerosol masking are causing Earth's energy imbalance to keep rising, which comes with feedbacks including more water vapor in the atmosphere, a decrease in lower clouds and decline of the snow and ice cover. 

The decline of sea ice is illustrated by the image below that shows the global sea ice area anomaly through September 21, 2025, when the global sea ice area was 2.48 million km² below the 1981-2010 mean, a deviation from 1981-2010 of -3.72σ. Critically, the global sea ice anomaly has been very low in 2025 (in blue) and this occurred in the absence of an El Niño.


Antarctic sea ice 

Ominously, the Antarctic sea ice area anomaly is very low. The image below shows the 2025 anomaly (in black) from April through September 22, 2025, when the Antarctic sea ice area was 1.30 million km² below the 1981-2010 mean, a deviation from 1981-2010 of -3.24σ. Note that, during the period shown on the image, very little sunlight has reached the Southern Hemisphere. 

This spells bad news for Antarctic sea ice, which almost crossed the threshold for a Blue Ocean Event on February 22, 2023, as illustrated by the image below. 

[ image from earlier post, click to enlarge ]

In conclusion, a Blue Ocean Event could occur in the Southern Hemisphere in early 2026. This could be followed by a Blue Ocean Event in the Northern Hemisphere later in 2026, in particular if a new El Niño will emerge in the course of 2026 and further feedbacks are triggered, such as seafloor methane eruptions. 

The danger is also illustrated by the image below, adapted from an image issued by NOAA September 22, 2025, showing hourly methane averages recorded at the Barrow Atmospheric Baseline Observatory (BRW), a NOAA facility located near Utqiaġvik (formerly Barrow), Alaska, at 71.32 degrees North.



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

• Kevin Pluck - Sea ice visuals
https://seaice.visuals.earth

• Danish Meteorological Institute - Arctic sea ice thickness and volume
https://ocean.dmi.dk/arctic/icethickness/thk.uk.php

• NOAA - Global Monitoring Laboratory - Data Visualisation - flask and station methane measurements
https://gml.noaa.gov/dv/iadv

• Record high increase in carbon dioxide 
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