Focus on Antarctica

The Antarctic sea ice area was 1.27 million km² below the 1981-2010 mean on September 23, 2025, a deviation from 1981-2010 of -3.05σ, as illustrated by the image below.

This is far below what the Antarctic sea ice area was in 1981-2010. If the situation gets worse over the next few months, an Antarctic Blue Ocean Event may well occur early 2026. In 2023, the Antarctic sea ice was very close to a Blue Ocean Event, with an area of only 1.09 million km² left on February 22, 2023, a deviation of -3.03σ, as illustrated by the image below.

[ image from earlier post, click to enlarge ]

The image below shows the Antarctic sea ice thickness on September 23, 2025. 

The image below shows the Antarctic sea ice concentration on September 23, 2025. 

Earth's energy imbalance

Temperatures keep rising as Earth's energy imbalance keeps rising, which results from a combination of high (and rising) levels of pollution (including concentrations of greenhouse gases, other gases and warming aerosols) and loss of Earth's albedo (reflectivity). Furthermore, rising temperatures come with feedbacks that can speed up acceleration of the temperature rise. 

The image below, by Eliot Jacobson, shows Earth's Energy Imbalance through July 2025 (12-month running mean). 

Albedo loss over the years is illustrated by the graph below, by Eliot Jacobson (based on data through July 2025, 36-month running average). 

Albedo loss results from a decrease in cooling aerosols and from certain feedbacks that are kicking in with increasing ferocity as temperatures rise, including less lower clouds and decline of the snow and ice cover. With the temperature rise also come further feedbacks such as more water vapor in the atmosphere and more extreme weather events that can cause deforestation and associated reductions in cooling aerosols, as illustrated by the Danger Diagram below. 

Many feedbacks are self-amplifying and can also amplify other feedbacks, further speeding up acceleration of the temperature rise, as illustrated by the image below. 

[ from earlier post ]

El Niño 2026 prospect

Furthermore, a new El Niño may emerge soon. El Niño-Southern Oscillation (ENSO) is a climate pattern that fluctuates from El Niño to La Niña conditions and back. El Niño raises temperatures, whereas La Niña suppresses temperatures. This year, there have been neutral to borderline La Niña conditions, as illustrated by the image below, which shows the rises and falls of the sea surface temperature in Niño 3.4, an area in the Pacific (inset) that is critical to the development of El Niño. 

On September 27, 2025, the temperature reached an anomaly in this area of -0.67°C versus 1991-2020. The inset on the above image shows the Niño 3.4 area and the sea surface temperature anomaly versus 1991-2020 that day. The low temperatures in Niño 3.4 over the past few months indicate that La Niña conditions will likely dominate in the remainder of 2025, which implies suppression of the 2025 global temperatures.

A strong La Niña could spell bad news for Antarctic sea ice. A recent study led by Shaoyin Wang shows that the triple-dip La Niña event during 2021–2023 played a major role in record low February Antarctic sea ice extent reached in 2022 and 2023, while the Antarctic ice sheet experienced a transient mass gain rebound.

As also described in earlier posts such as this one and this one, more water evaporates from the Southern Ocean and part of it falls on the Antarctic ice sheet, thickening the snow layer. As a result, the Southern Ocean surface is getting more salty. 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.

[ image from earlier post ]

On the other hand, a new El Niño may emerge soon. The image on the right, adapted from ECMWF, shows an ENSO forecast for developments in Niño3.4 through August 2026, indicating that the next El Niño may emerge in 2026 and grow in strength in the course of 2026.

In conclusion, an Antarctic Blue Ocean Event may occur early 2026 and this could be followed by an Arctic Blue Ocean Event later in 2026, in particular if a strong El Niño will emerge in the course of 2026 and further feedbacks are triggered, such as seafloor methane eruptions. 

Why a Blue Ocean Event is so dangerous

[ from earlier post ]

PIOMAS estimates that 16,400 km³ of ice is lost every year (1979-2010 average) from April to September, consuming an amount of energy of 5 x 10²¹ Joules (the image on the right shows calculations, click on this link or on the image to enlarge).

Once the latent heat buffer is lost, further heat must go elsewhere. During the phase change from ice to water, the temperature doesn't rise, i.e. all the energy goes into the process of changing ice into water. Once all ice has melted, further heat will raise the temperature of the water. The amount of energy that is consumed in the process of melting the ice is as much as it takes to heat an equivalent mass of water from zero°C to 80°C. 

Decline of the snow and ice cover comes with numerous feedbacks, the loss of the latent heat buffer (feedback #14 on the feedbacks page) is only one of them. Further feedbacks include the loss of albedo (feedback #1), increases in emissions (feedback #2), loss of emissivity (feedback #23), while there are also changes to the Jet Stream (feedback #14) and changes to clouds and water vapor (feedback #20), and there are mechanisms and circumstances aggravating the danger, such as the slowdown of AMOC and further changes to ocean currents.

[ The Buffer is gone, from Accelerating Temperature Rise ]

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.

Eruption of methane from the seafloor of the Arctic Ocean (feedback #16) is one of the most dangerous feedbacks. As the seafloor of the Arctic Ocean heats up, heat can penetrate sediments and cause destabilization of hydrates, resulting in eruption of methane. As the seas in the Arctic Ocean can be very shallow, the methane can erupt with force in the form of plumes, with 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.

Ominously, the sea surface temperature anomaly versus 1951-1980 in the north mid latitudes (inset) reached a record monthly high of 1.657°C in August 2025, as illustrated by the image below.

Meanwhile, the Arctic sea ice remains at a record low daily volume, as it has been for more than a year.  

The methane danger is also illustrated by the image below, adapted from an image issued by NOAA September 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. 

The image below shows methane concentrations as high as 2622 parts per billion (ppb) recorded by the NOAA 20 satellite on September 30, 2025 am, at 399.1 mb. Note the high methane concentrations over the Arctic, over Antarctica and over the Antarctic sea ice.

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

• University of Bremen - sea ice concentration and thickness
https://seaice.uni-bremen.de/start

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

• Record high increase in carbon dioxide
https://arctic-news.blogspot.com/2025/04/record-high-increase-in-carbon-dioxide.html

• Double Blue Ocean Event 2026?
https://arctic-news.blogspot.com/2025/09/double-blue-ocean-event-2026.html

• Strong impact of the rare three-year La Niña event on Antarctic surface climate changes in 2021–2023 - by Shaoyin Wang et al.
https://www.nature.com/articles/s41612-025-01066-0

• Extreme Heat Risk
https://arctic-news.blogspot.com/2025/08/extreme-heat-risk.html

• Saltier water, less sea ice 

https://arctic-news.blogspot.com/2025/07/saltier-water-less-sea-ice.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

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 

https://arctic-news.blogspot.com/2025/04/record-high-increase-in-carbon-dioxide.html

• Double Blue Ocean Event 2026?

https://arctic-news.blogspot.com/2025/09/double-blue-ocean-event-2026.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

Double Blue Ocean Event 2026?

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 Buffer is gone, from Accelerating Temperature Rise ]

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. 

[ image from earlier post ]

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.

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

• 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

El Nino 2026, extinction?

El Niño-Southern Oscillation (ENSO) is a climate pattern that fluctuates from El Niño to La Niña conditions and back. El Niño raises temperatures, whereas La Niña suppresses temperatures. This year, there have been neutral to La Niña conditions, as illustrated by the image below, which also shows that over the past few months, there has been a zigzag pattern of rises and falls around the mean sea surface temperature in Niño 3.4, an area in the Pacific (inset) that is critical to the development of El Niño. 

    [ click on images to enlarge ]

On September 13, 2025, the temperature reached an anomaly in this area of -0.54°C versus 1991-2020, indicating that La Niña conditions are likely to dominate late 2025/early 2026. The inset on the above image shows the Niño 3.4 area and sea surface temperature anomalies versus 1991-2020 on that day.

The image on the right, adapted from NOAA, shows the ENSO outlook (CFSv2 ensemble mean, black dashed line) favoring La Niña late 2025/early 2026. 

[ image from earlier post ]

The image on the right, adapted from ECMWF, shows an ENSO forecast for developments in Niño3.4 through August 2026, indicating that the next El Niño may emerge early 2026 and grow in strength in the course of 2026.

Rising temperature in absence of El Niño

Critical is the temperature on land, which is after all where people live. The image below shows that in 2025, monthly temperature anomalies (from 1880-1920) on land have fallen from a high of +2.93°C in January 2025 to +1.45°C in July 2025, in line with the temperature suppression that comes with a move into La Niña. 

The anomaly was +2.93°C in January 2025, very close to +3°C. Note that when using a genuinely pre-industrial base, anomalies can be much higher than depicted in the above image. While anomalies have come down somewhat, the anomaly rose again to +1.82°C in August 2025, which could indicate that acceleration of the temperature rise is overwhelming the temperature suppression that comes with a move into La Niña. 

The sea surface temperature anomaly keeps rising, in particular from the latitudes of 30° and higher north, as illustrated by the image below. 

Adding to fears that the temperature rise is accelerating despite the absence of El Niño is the most recent rise of the global temperature anomaly. As illustrated by the image below, the global temperature anomaly versus 1991-2020 has risen strongly recently, from +0.21°C on July 4, 2025, to +0.83°C on September 20, 2025. 

A +3°C temperature rise constitutes an important threshold, since humans will likely go extinct with such a rise, as illustrated by the image below. 

[ from the post When will humans go extinct? ]

   [ from: When Will We Die? ]

Recent research led by David Fastivich finds that, historically, vegetation responded at timescales from hundreds to tens of thousands of years, but not at timescales shorter than about 150 years. It takes centuries for tree populations to adapt - far too slow to keep pace with today’s rapidly warming world.

Note that healthy vegetation relies not only on temperature, but also on the presence of good soil, microbes, rain, soil nutrients, pollinators, habitat, groundwater and an absence of toxic waste, pests and diseases.

A 2018 study by Strona & Bradshaw indicates that most life on Earth will disappear with a 5°C rise (see box on the right). Humans, who depend on a lot of other species, will likely go extinct with a 3°C rise, as discussed in the earlier post When Will We Die?

The map below shows the size of the population rather than the size of the territory, decreasing the size of Canada, Mongolia, Australia, and Russia, and highlighting how many people are vulnerable to heat stress.

[ cartogram from Ourworldindata.org - click to enlarge ]

In the video below, Herb Simmens discussed the situation with Peter Carter and Paul Beckwith. 

Climate Emergency Declaration

The temperature rise is accelerating and the rise could accelerate even more due to decreases in buffers (as described in earlier posts such as this one), due to strengthening feedbacks, especially during an El Niño, and due to further reduction of the aerosol masking effect, which are all developments that could rapidly speed up existing feedbacks and trigger new feedbacks.

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

• Climate Reanalyzer
https://climatereanalyzer.org

• NOAA - Climate Prediction Center - ENSO: Recent Evolution, Current Status and Predictions
https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf

• ECMWF - El Niño forecast
https://charts.ecmwf.int/products/seasonal_system5_nino_annual_plumes

• NASA - surface temperature analysis - gistemp 
https://data.giss.nasa.gov/gistemp

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

• Population cartogram
https://ourworldindata.org/world-population-cartogram

discussed on Facebook at: 
https://www.facebook.com/groups/arcticnews/permalink/10163232140864679

• 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