Both Arctic and Antarctic sea ice may be gone within ten months. On April 24, 2026, Arctic sea ice was lowest for the time of year in extent, in area and in volume, as highlighted in an earlier post. The post warns that the upcoming El Niño could cause all Arctic sea ice to disappear in September 2026, resulting in albedo loss, transfer of ocean heat to the atmosphere and additional emissions that could jointly increase global temperatures and subsequently also cause all Antarctic sea to disappear in a matter of months.
The upcoming El Niño threatens to become a monster within months.
The above image, adapted from NOAA, shows a forecast dated May 1, 2026, for the Niño3.4 region (which is indicative for El Niño development), with forecasts partly exceeding 4°C for some forecast members, while part of the forecast for the Coupled Forecast System version 2 (CFS.v2) ensemble mean (black dashed line) exceeds 3°C. The image below shows forecasts for the Niño3 region dated May 1, 2026.
Forecasts of anomalies in sea surface temperature anomalies in El Niño regions reaching or exceeding 3°C indicate that the 2026 El Niño will be even stronger than the 2015-16 El Niño, as illustrated by the image below, adapted from NOAA and with a potential 2026-27 El Niño anomaly of 3°C added in red. Note that the image below uses the relative Oceanic Nino Index (RONI), whereas the above forecasts use the Oceanic Nino Indec (ONI) that can show slightly higher anomalies.
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| [ from earlier post ] |
The image below shows the sea surface temperature (SST) in the Nino 3.4 region over the years from the start of the year to June. On April 3, the 2026 SST (red line) was higher than the 2016 SST (thick grey line). From January 9, 2026, through April 30, 2026, the sea surface temperature in the Nino3.4 region has risen by 3.15°C.
Arctic sea ice
The image below, adapted from the Danish Meteorological Institute, shows Arctic sea ice volume at a record low for the time of year on May 1, 2026.
The April 2026 Arctic sea ice maximum volume was about 18,000 km³, as highlighted by the image on the right, even lower than the 2025 maximum.
That 18,000 km³ is an important number. The image below shows Arctic sea ice volume, 2026, with the strength of the melting between April (annual maximum, blue) and September (annual minimum, red) highlighted by bars colored magenta (strong melting, 18,000 km³) and green (little melting, 15,000 km³).
Relatively little melting took place from April 2025 to September 2025, yet a record low minimum volume was reached in September 2025. The April 2026 maximum is even lower, i.e. about 18,000 km³.
In the above image, the difference between strong melting (magenta) and little melting (green) is 3000 km³. With strong melting taking place from April 2026, this may well cause a Blue Ocean Event to occur, with virtually all Arctic sea disappearing in September 2026.
Feedbacks
A further danger lies in changes occurring to wind and ocean current patterns; the temperature rise will cause stronger wind, waves and storms, as well as deformation of the Jet Stream (Feedback #19). In addition, the temperature rise causes loss of reflectivity of clouds (Feedback #25) and more ocean stratification (Feedback #29), exacerbated by more freshwater accumulating at the surface of oceans, due to stronger ice melting, due to heavier runoff from land and rivers and due to changes in wind patterns and ocean currents and circulation. In the North Atlantic, there is the additional danger that formation of a freshwater lid (Feedback #28) will cause huge amounts of ocean heat to be pushed into the Arctic Ocean and enter the atmosphere as sea ice disappears.
The image below illustrates the mechanism of how multiple feedbacks increase and accelerate the temperature rise of the atmosphere (the yellow horizontal bar).
The feedback numbers correspond with the list at the feedbacks page. Some of them are discussed below.
Feedback #1: albedo loss (loss of reflectivity) as sea ice melts due to rising temperatures and due to the ice getting covered by soot, dust, algae, meltpools and rainwater pools;
Feedback #14: loss of the latent heat buffer - as sea ice disappears, heat can no longer be consumed by the process of melting, and the heat will instead go into increasing the temperature;
Feedback #16: eruptions of seafloor methane - as more heat reaches the seafloor of the Arctic Ocean, sediments and hydrates contained in them destabilize, resulting in methane releases. Vast amounts of methane are held in hydrates at the seafloor of the Arctic Ocean. Miesner et al. (2023) warn that 2822 Gt of organic carbon is stored in subsea Arctic shelf permafrost and Huang et al. (2024) warn that the top two meters of soil globally holds about 2300 Gt of inorganic carbon, which has been left out of environmental models, and 23 Gt of this carbon may be released over the next 30 years. By comparison, the atmosphere contains about 5 Gt of methane. The image below, from an earlier post, illustrates the threat of thinning of Arctic sea ice resulting in increased ocean heat and methane eruptions.
Sea ice loss comes many feedbacks and there is interaction between feedbacks. As an example, sea ice decline comes with both loss of albedo (Feedback #1) and loss of the latent heat buffer (Feedback #14), each of which will accelerate the temperature rise of the water of the Arctic Ocean, thus contributing to the threat that hydrates contained in sediments at the seafloor of the Arctic Ocean will be destabilized, which in turn threatens to cause eruption of huge amounts of methane (Feedback #16), which will further drive up the temperature in the Arctic and cause stronger melting of terrestrial permafrost.
A further danger lies in changes occurring to wind and ocean current patterns; the temperature rise will cause stronger wind, waves and storms, as well as deformation of the Jet Stream (Feedback #19). In addition, the temperature rise causes loss of reflectivity of clouds (Feedback #25) and more ocean stratification (Feedback #29), exacerbated by more freshwater accumulating at the surface of oceans, due to stronger ice melting, due to heavier runoff from land and rivers and due to changes in wind patterns and ocean currents and circulation. In the North Atlantic, there is the additional danger that formation of a freshwater lid (Feedback #28) will cause huge amounts of ocean heat to be pushed into the Arctic Ocean and enter the atmosphere as sea ice disappears.
The image below illustrates the mechanism of how multiple feedbacks increase and accelerate the temperature rise of the atmosphere (the yellow horizontal bar).
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| [ image from earlier post ] |
Feedback #1: albedo loss (loss of reflectivity) as sea ice melts due to rising temperatures and due to the ice getting covered by soot, dust, algae, meltpools and rainwater pools;
Feedback #14: loss of the latent heat buffer - as sea ice disappears, heat can no longer be consumed by the process of melting, and the heat will instead go into increasing the temperature;
Feedback #16: eruptions of seafloor methane - as more heat reaches the seafloor of the Arctic Ocean, sediments and hydrates contained in them destabilize, resulting in methane releases. Vast amounts of methane are held in hydrates at the seafloor of the Arctic Ocean. Miesner et al. (2023) warn that 2822 Gt of organic carbon is stored in subsea Arctic shelf permafrost and Huang et al. (2024) warn that the top two meters of soil globally holds about 2300 Gt of inorganic carbon, which has been left out of environmental models, and 23 Gt of this carbon may be released over the next 30 years. By comparison, the atmosphere contains about 5 Gt of methane. The image below, from an earlier post, illustrates the threat of thinning of Arctic sea ice resulting in increased ocean heat and methane eruptions.
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| [ The Buffer is gone ] |
Feedback #19: distortion of the Jet Stream as the temperature difference narrows between the Arctic and the Tropics, in turn causing further feedbacks to kick in stronger, such as hot air moving into the Arctic and cold air moving out, and more extreme weather events bringing heavier rain and more intense heatwaves, droughts and forest fires that cause black carbon to settle on the sea ice;
Feedback #23: open oceans hold more far-infrared energy than sea ice, resulting in warmer oceans, stronger melting of sea ice, with a study showing a 2°C rise in the polar climate after a 25-year run;
Feedback #25: extra water vapor feedback - rising temperatures will result in more water vapor in the atmosphere (7% more water vapor for every 1°C warming), further amplifying the temperature rise, since water vapor is a potent greenhouse gas;
Feedback #28: freshwater lid on the North Atlantic - melting of sea ice and glaciers and thawing of the permafrost results in meltwater accumulating at the surface of the North Atlantic Ocean, where it forms a cold freshwater lid on top of the water; this lid grows further due to more rain falling on top of this lid. This results in less evaporation and transfer of heat from the North Atlantic to the atmosphere, and more ocean heat getting carried by the Gulf Stream underneath the sea surface into the Arctic Ocean.
Feedback #23: open oceans hold more far-infrared energy than sea ice, resulting in warmer oceans, stronger melting of sea ice, with a study showing a 2°C rise in the polar climate after a 25-year run;
Feedback #25: extra water vapor feedback - rising temperatures will result in more water vapor in the atmosphere (7% more water vapor for every 1°C warming), further amplifying the temperature rise, since water vapor is a potent greenhouse gas;
Feedback #28: freshwater lid on the North Atlantic - melting of sea ice and glaciers and thawing of the permafrost results in meltwater accumulating at the surface of the North Atlantic Ocean, where it forms a cold freshwater lid on top of the water; this lid grows further due to more rain falling on top of this lid. This results in less evaporation and transfer of heat from the North Atlantic to the atmosphere, and more ocean heat getting carried by the Gulf Stream underneath the sea surface into the Arctic Ocean.
Antarctic sea ice
Could an Antarctic Blue Ocean Event occur in early 2027? As illustrated by the image below, 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.
What caused the 2023 Antarctic sea ice decline? Until 2015, rising temperatures resulted in melting of ice and enhanced precipitation that freshened the surface of the Southern Ocean, exacerbated by increasing stratification that prevented mixing. The temperature rise over the years also caused winds to be stronger, at the time causing the sea ice to spread out wider.
The higher the water's salt content, the lower its melting point. Seawater typically has a salinity of about 3.5% (35 grams of salt per liter of water). Sea ice starts melting when the temperature rises to about -2°C (28.4°F). By contrast, freshwater remains frozen as long as the temperature remains below 0°C (32°F).
A recent study led by Theo Spira finds that, in 2015, anomalously strong winds enhanced mixing across the thin Winter Water layer, entraining warm and salty subsurface waters, which broke down upper-ocean stratification. Another recent study led by Earle Wilson find that in 2015, intensified wind-driven upwelling reversed the freshening trends, releasing years of accumulated ocean heat that contributed to unprecedented sea ice loss.
An earlier post discusses a study led by Alessandro Silvano that finds how, around 2015, surface salinity in the Southern Ocean began rising sharply – just as sea ice extent started to crash.
The post describes that higher temperatures come with feedbacks such as stronger wind and stronger evaporation, resulting in increased water vapor in the atmosphere. Much of the water vapor will return to the surface in the form of precipitation such as rain and snow, but part of this precipitation will fall over Antarctica, with the net result of an increase in salinity of surface of the Southern Ocean.
Could an Antarctic Blue Ocean Event occur in early 2027? As illustrated by the image below, 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.
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| [ Saltier water, less sea ice - from earlier post ] |
The higher the water's salt content, the lower its melting point. Seawater typically has a salinity of about 3.5% (35 grams of salt per liter of water). Sea ice starts melting when the temperature rises to about -2°C (28.4°F). By contrast, freshwater remains frozen as long as the temperature remains below 0°C (32°F).
A recent study led by Theo Spira finds that, in 2015, anomalously strong winds enhanced mixing across the thin Winter Water layer, entraining warm and salty subsurface waters, which broke down upper-ocean stratification. Another recent study led by Earle Wilson find that in 2015, intensified wind-driven upwelling reversed the freshening trends, releasing years of accumulated ocean heat that contributed to unprecedented sea ice loss.
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| [ image from: 10°C or 18°F warmer by 2021? ] |
The post describes that higher temperatures come with feedbacks such as stronger wind and stronger evaporation, resulting in increased water vapor in the atmosphere. Much of the water vapor will return to the surface in the form of precipitation such as rain and snow, but part of this precipitation will fall over Antarctica, with the net result of an increase in salinity of surface of the Southern Ocean.
The post also points at the danger that heat, previously stored in the deep ocean by sinking circumpolar waters, will instead remain at the surface and cause atmospheric temperatures to rise, as illustrated by the above image.
A recent study warns that Antarctic regions (60°S − 90°S) may warm by around 6°C due to the collapse of the Atlantic meridional overturning circulation (AMOC).
A recent study warns that Antarctic regions (60°S − 90°S) may warm by around 6°C due to the collapse of the Atlantic meridional overturning circulation (AMOC).
Conclusion
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 in this 2022 post and this 2025 post, and as discussed in the Climate Plan group.
Links
• NOAA - Seasonal climate forecast from CFSv2
https://www.cpc.ncep.noaa.gov/products/CFSv2/CFSv2_body.html
• NOAA - ENSO: Recent Evolution, Current Status and Predictions - Update issued April 27, 2026
https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf
• Climate Reanalyzer
https://climatereanalyzer.org
• Danish Meteorological Institute - Arctic sea ice volume and thickness
https://ocean.dmi.dk/arctic/icethickness/thk.uk.php
• 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
https://www.cpc.ncep.noaa.gov/products/CFSv2/CFSv2_body.html
• NOAA - ENSO: Recent Evolution, Current Status and Predictions - Update issued April 27, 2026
https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf
• Climate Reanalyzer
https://climatereanalyzer.org
• Danish Meteorological Institute - Arctic sea ice volume and thickness
https://ocean.dmi.dk/arctic/icethickness/thk.uk.php
• 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
