Arctic sea ice volume is at a record daily low. It has been at a record daily low for well over a year. The image below shows Arctic sea ice volume through December 1, 2025.
The image below shows that the Arctic sea ice extent was at a record daily low on December 1, 2025.
Loss of sea ice extent means that less sunlight gets reflected back into space and instead gets absorbed by the sea surface, resulting in higher temperatures, in a self-amplifying feedback loop.
Furthermore, loss of Arctic sea ice volume can contribute to a huge rise in temperature as a result of methane erupting from the seafloor of the Arctic Ocean. As Arctic sea ice shrinks in volume, its capacity shrinks to act as a buffer that consumes ocean heat entering the Arctic Ocean from the Atlantic Ocean. As the buffer disappears, the temperature of the water can rise strongly and abruptly, causing heat to penetrate sediments that contain huge amounts of methane in the form of hydrates and free gas underneath hydrates. Heat penetrating such sediments can destabilize such hydrates, resulting in huge eruptions of methane.
Such an event could be triggered by wild weather swings resulting from higher temperatures that come with the next El Niño that may emerge and strengthen in the course of the year 2026.
The next El Niño
[ click on images to enlarge ]
The image on the right shows a NOAA update of temperature anomalies and forecasts in the Niño-3.4 region. NOAA considers La Niña conditions to occur when a one-month negative sea surface temperature anomaly of -0.5° C or less is observed in the Niño-3.4 region of the equatorial Pacific Ocean (5°N-5°S, 120°W-170°W). Also, there must be an expectation that the 3-month Oceanic Niño Index (ONI) threshold will be met, and an atmospheric response typically associated with La Niña is observed over the equatorial Pacific Ocean. These anomalies must also be forecasted to persist for 3 consecutive months.
The image below, adapted from ECMWF, shows the ENSO anomalies and forecasts for developments through November 2026 in Niño3.4 (left panel) and in Niño1+2 (right panel), indicating that the next El Niño will emerge and strengthen in the course of 2026.
Moving from the depth of a La Niña to the peak of a strong El Niño in itself can make a difference in the global temperature of more than 0.5°C, as discussed in an earlier post.
Methane
The methane danger is discussed in many earlier posts such as this one and is further illustrated by the image below that shows hourly average in situ methane measurements well above 2400 ppb (parts per billion). The image is adapted from an image issued by NOAA December 1, 2025. The image shows methane recorded over the past few years at the Barrow Atmospheric Baseline Observatory (BRW), a NOAA facility located near Utqiaġvik (formerly Barrow), Alaska, at 71.32 degrees North latitude.
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
• Danish Meteorological Institute - Arctic sea ice thickness and volume
Vast amounts of methane are held in sediments at the seafloor of oceans, in the form of hydrates and in the form of free gas held underneath hydrates. Heat penetrating these sediments can destabilize hydrates and cause huge amounts of methane to erupt abruptly and enter the atmosphere.
The danger is large during the Northern Summer when Arctic sea ice reaches its minimum extent and more sunlight is heating up its shallow waters. As described below, the danger is also large outside this period.
At this time of year, Arctic sea ice is expanding rapidly, resulting in much of the Arctic Ocean getting covered with sea ice, as illustrated by the image on the right that shows Arctic sea ice concentration on November 24, 2025.
A thin layer of sea ice has sealed off the East Siberian Sea and the Laptev Sea from the atmosphere, resulting in less heat getting transferred from these seas to the atmosphere, so more heat remains in the water. This keeps the temperature of the water high, so the danger of methane eruptions remains high.
Furthermore, the temperature rise is hitting the Arctic stronger than elsewhere, resulting in more extreme weather events occurring in the Northern Hemisphere such as strong wind over the North Atlantic abruptly pushing much ocean heat from the North Atlantic into the Arctic Ocean, which can trigger destabilization of sediments at the seafloor of the Arctic Ocean at times when the ocean surface is sealed off by sea ice, reducing the ocean heat that can get transferred to the atmosphere.
Such an event occurred in February 2017 when strong wind was forecast to cause above-freezing temperatures at the North Pole, as described in an earlier post that also features the above map, indicating ocean heat getting carried along the path of the Gulf Stream into the Arctic ocean.
The image on the right shows sea surface temperatures as high as 31.2°C in the North Atlantic on November 25, 2025, while the Gulf Stream continues to push heat north toward the Arctic Ocean.
Arctic sea ice volume remains at a record daily low, as it has been for more than a year. This implies that Arctic sea ice is very thin. The image below shows Arctic sea ice volume through November 30, 2025.
Ocean heat flowing into the Arctic Ocean causes Arctic sea ice to lose thickness and volume, reducing its capacity to act as a buffer that consumes ocean heat entering the Arctic Ocean from the North Atlantic. This means that - as sea ice thickness decreases - a lot of incoming ocean heat can no longer be consumed by melting the sea ice from below, and the heat will therefore contribute to higher temperatures of the water of the Arctic Ocean. The danger of this is described in the screenshot below, which also points at the danger of a freshwater lid forming at the surface of the North Atlantic, further reducing transfer of ocean heat to the atmosphere.
Arctic sea ice extent was 9.27 million km² on November 30, 2025, a record low for this time of year, which is even more significant since this daily record low extent was reached in the absence of El Niño conditions elevating the temperature. The image below was created with a screenshot from the Japanese National Institute of Polar Research.
[ click on images to enlarge ]
The image below shows the anomaly. Arctic sea ice extent was 9.35 million km² on November 26, 2026, a record daily low and 1.97 million km² lower than 1981-2020 on November 26, 2025, a deviation from 1981-2010 of -3.42σ.
The image below shows that the global sea ice extent was 3.49 million km² lower than 1981-2020 on November 26, 2025, a deviation from 1981-2010 of -5.34σ.
Antarctica
Sea ice extent is currently low at both poles. The low global sea ice extent at this time of year combined with high sea surface temperatures spells bad news for Antarctic sea ice, which typically reaches its minimum extent in February.
The image on the right shows Antarctic snow cover and sea ice concentration on November 24, 2025.
An Antarctic Blue Ocean Event (sea ice approaching a low of one million km²) threatens to occur in February 2026, in turn triggering an Arctic Blue Ocean Event later in 2026.
The image below shows the Antarctic sea ice concentration (left) and thickness (right) thickness on November 27, 2025.
The image below shows that the Antarctic temperature was at a record daily high on November 26, 2025, 3.67°C higher than 1979-2020. The inset shows temperature anomalies that day, highlighting Antarctica.
The image below shows the rise of the Antarctic temperature anomaly (versus 1951-1980) for the 12-month period from November through October over the years. The inset shows Antarctica from 60°S.
Higher temperatures result in decline of the snow and ice cover, which means that less sunlight gets reflected back into space and instead gets absorbed by the sea surface, resulting in higher temperatures, in a self-amplifying feedback loop.
Less Antarctic sea ice contributes strongly to lower albedo (reflectivity), due to the size of Antarctic sea ice and its proximity to the Equator. The image below, by Eliot Jacobson, shows that the 36-month running average for the Earth albedo just hit yet another new record low, at 28.693%.
Huge temperature rise
The image below shows global surface daily air temperature anomalies in °C versus 1991-2020 (ERA5 data through November 22, 2025). The added trend warns about a 10°C rise in 2026. The inset shows the rise 2023-2025.
The image below shows that the temperature was at a record daily high on November 23, 2025.
[ click on images to enlarge ]
What could contribute to a huge rise in temperature is methane erupting from the seafloor, triggered by higher temperatures and more wild weather swings as El Niño emerges and strengthens, which in itself could make a difference of as much as 0.5°C, as discussed in an earlier post. The image on the right shows an update of temperatures in the Niño-3.4 region.
NOAA considers La Niña conditions to occur when a one-month negative sea surface temperature anomaly of -0.5° C or less is observed in the Niño-3.4 region of the equatorial Pacific Ocean (5°N-5°S, 120°W-170°W).
Also, there must be an expectation that the 3-month Oceanic Niño Index (ONI) threshold will be met, and an atmospheric response typically associated with La Niña is observed over the equatorial Pacific Ocean. These anomalies must also be forecasted to persist for 3 consecutive months.
The image on the right features a graph using CDAS (Climate Data Assimilation System) data that show an anomaly of -1.24°C on Nov 26, 2025.
The image on the right, adapted from ECMWF and from an earlier post, shows the ENSO anomaly and forecast for developments in Niño3.4 through November 2026, indicating the next El Niño will emerge and strengthen in the course of 2026.
The CDAS analysis below shows very low sea surface temperature anomalies (in blue) in the Niño3.4 area in the Central Pacific on November 26, 2025. Moving from the depth of a La Niña to the peak of a strong El Niño can make a difference in the global temperature of more than 0.5°C, as discussed in an earlier post.
Methane
The methane danger is further illustrated by the images below. The image directly below shows methane as high as 2601 parts per billion (ppb) recorded by the NOAA 21 satellite at 399.1 mb on November 21, 2025 PM.
The image below shows hourly in situ methane measurements well above 2400 ppb. The image is adapted from an image issued by NOAA November 23, 2025, showing methane hourly averages recorded at the Barrow Atmospheric Baseline Observatory (BRW), a NOAA facility located near Utqiaġvik (formerly Barrow), Alaska, at 71.32 degrees North latitude.
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
• Permafrost Thaw is Warming the Global Climate and Impacts Communities, Health, and Oceans - by International Cryosphere Climate Initiative
The Arctic sea ice area reached its annual minimum on September 9, 2025, as described in an earlier post. The image below shows Arctic sea ice volume through October 5, 2025, with Arctic sea ice volume at a record daily low, as it has been for more than a year.
The image below shows monthly Arctic sea ice volume in the past 25 years. Markers show April (blue) and September (red) volume, corresponding with the year's maximum and minimum. In 2025, Arctic sea ice reached a record low maximum volume as well as a record low minimum volume.
Warmer water flowing into the Arctic Ocean causes Arctic sea ice to lose thickness and thus volume, diminishing its capacity to act as a buffer that consumes ocean heat entering the Arctic Ocean from the North Atlantic. This means that - as sea ice thickness decreases - a lot of incoming ocean heat can no longer be consumed by melting the sea ice from below, and the heat will therefore contribute to higher temperatures of the water of the Arctic Ocean. The danger of this is described in the screenshot below.
Lower air temperatures are now causing rapid growth of Arctic sea area, which is sealing off the Arctic Ocean and this makes it more difficult for ocean heat to be transferred to the atmosphere, thus aggravating the danger that more ocean heat will reach sediments at the seafloor of the Arctic Ocean and will destabilize methane hydrates contained in sediments.
The methane danger is also illustrated by the image below, adapted from an image issued by NOAA October 2, 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 Diagram and Assessment
The following can be added to the above diagram: Polar amplification of the temperature rise is causing the temperature difference between the Poles and the Equator to narrow, which can at times result in a distorted Jet Stream reaching high latitudes in the Northern Hemisphere, as well as in the Southern Hemisphere. This can lead to acceleration of the temperature rise in a number of ways, not only due to albedo loss, but also through loss of sea ice and oceans in their capacity to act as heat buffers, as illustrated by the images below.
The first image (below) shows a distorted Jet Stream moving over the North Pole and over Antarctica, at speeds of up to 160 km/h or 100 mph on October 9, 2025, 10:00 UTC.
The second image (below) shows the temperature anomaly on October 9, 2025, with high temperature anomalies showing up over the Arctic Ocean and over parts of Antarctica.
The third image (below) shows precipitable water anomalies on October 8, 2025, with very high precipitable water anomalies over the Arctic Ocean and over parts of Antarctica.
The fourth image (below) shows precipitation on October 8, 2025, with part of the water that has evaporated from the Southern Ocean falling in the form of snow on the Antarctic ice sheet, thickening the snow layer.
What the above images show is not a one-off situation. The image on the right shows a forecast of the precipitable water standardized anomaly for October 13, 2025.
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.
As 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 Heat Buffer loss diagram below illustrates the above-described feedback mechanism.
Loss of the ocean heat buffer is a very dangerous feedback mechanism. The high (and rising) concentrations of warming aerosols, greenhouse gases and other gases are causing extra heat in the atmosphere. Some 90% of this extra heat used to be taken up by oceans. Even a small decrease in this percentage can dramatically increase air temperatures.
The very continuation of life on Earth is at stake and the sheer potential that all life on Earth may be condemned to disappear due to a refusal by some people to do the right thing, that should prompt the whole world into rapid and dramatic climate action.
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.
A double Blue Ocean Event could occur in 2026. Both Antarctic sea ice and Arctic sea ice could virtually disappear in 2026. A Blue Ocean Event (BOE) occurs when sea ice falls to or under 1 million km², which could occur early 2026 for Antarctic sea ice area and in Summer 2026 in the Northern Hemisphere for Arctic sea ice area.
Arctic sea ice area reached an annual minimum of 2.70 million km² on September 9, 2025, the fourth-lowest minimum area, as illustrated by the image below.
The low Arctic sea ice area is worrying, especially when considering that this minimum was reached in the absence of El Niño conditions. Lower air temperatures are now causing rapid growth of Arctic sea area, which is sealing off the Arctic Ocean and this makes it more difficult for ocean heat to be transferred to the atmosphere. Furthermore, Arctic sea ice volume was at a record daily low on September 16, 2025, as it has been for more than a year, as illustrated by the image below.
More ocean heat could therefore reach sediments at the seafloor of the Arctic Ocean, which threatens to destabilize hydrates and cause huge amounts of methane to be released. Eruption of methane from the seafloor of the Arctic Ocean is one of the most dangerous feedbacks of rising temperatures. As the seafloor of the Arctic Ocean heats up, heat can penetrate sediments and cause destabilization of hydrates, resulting in eruption of methane. Since the seas in the Arctic Ocean can be very shallow, methane eruptions can occur abruptly, with great force and in the form of plumes, leaving little opportunity for the methane to get decomposed in the water. Furthermore, there is very little hydroxyl in the air over the Arctic, which extends the lifetime of methane over the Arctic.
The above image illustrates the danger. Sea ice constitutes a buffer that previously consumed much incoming ocean heat (left); as sea ice thins, the buffer disappears while more heat also enters the Arctic Ocean (right). Further heat entering the Arctic Ocean from the Atlantic Ocean and the Pacific Ocean threatens to destabilize sediments that contain methane, causing eruption of huge amounts of methane.
The danger is also illustrated by the image below, adapted from an image issued by NOAA September 18, 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.
Antarctic sea ice area reached an annual maximum of 13.73 million km² on September 5, 2025, a deviation from 1981-2010 of -2.08σ, as illustrated by the image below.
Loss of sea ice area results in less sunlight getting reflected back into space and instead more heat getting absorbed by the ocean.
Sea ice area is low at both poles, despite the absence of El Niño conditions. Low global sea ice area causes more sunlight to get absorbed by the ocean. Global sea ice area was 2.40 million km² below the 1981-2010 mean on September 16, 2025, a deviation from 1981-2010 of 3.91σ.
With sea ice area low at both poles, global sea ice area could fall further over the next few months, thus causing even more sunlight to get absorbed by the ocean and threatening to cause an Antarctic Blue Ocean Event early 2026.
On March 1, 2025, Antarctic sea ice area reached an annual minimum of 1.21 million km², almost as low as the 1.09 million km² reached on February 22, 2023 (highlighted), as illustrated by the image below.
A study by Duspayev et al. (2024) calculates that global sea ice has lost 13%–15% of its planetary cooling effect since the early/mid 1980s, corresponding with an implied global sea ice albedo feedback of 0.24–0.38 W m⁻² K⁻¹.
The IPCC has failed to warn about Antarctic sea ice decline, and - importantly - the amplifying impact of Antarctic sea ice decline on the global temperature rise. This was addressed in a 2023 post as follows: Sea ice loss results in less sunlight getting reflected back into space and instead getting absorbed by the ocean and the impact of Antarctic sea ice loss is even stronger than Arctic sea ice loss, since Antarctic sea ice is located closer to the Equator, as pointed out by Paul Beckwith in a video in an earlier post [and in the video below]. A warmer Southern Ocean also comes with fewer bright clouds, further reducing albedo, as discussed here and here. For decades, there still were many lower clouds over the Southern Ocean, reflecting much sunlight back into space, but these lower clouds have been decreasing over time, further speeding up the amount of sunlight getting absorbed by the water of the Southern Ocean, and this 'pattern effect' could make a huge difference globally, as this study points out. Emissivity is a further factor; open oceans are less efficient than sea ice when it comes to emitting in the far-infrared region of the spectrum (feedback #23 on the feedbacks page).
In the video below, Paul Beckwith discusses the situation in Antarctica.
An Antarctic Blue Ocean Event early 2026 would further accelerate the global temperature rise, thus likely causing an Arctic Blue Ocean Event as well later in 2026. Further increasing this danger is the potential for an El Niño to emerge in the course of 2026.
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.
