Sunday, November 2, 2025

The threat of seafloor methane eruptions

Arctic sea ice volume

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 November 7, 2025.


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.

[ from earlier post ]
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.

[ screenshot from earlier post ]
Sea ice extent

Arctic sea ice extent was 7.91 million km² on November 5, 2025, second daily low on record and a deviation from 1981-2010 of -3.95σ.


The image below shows that the global sea ice extent was at a record daily low on November 5, 2025, a deviation from 1981-2010 of -6.99σ, which is terrifying given the absence of El Niño conditions in 2025.


Low sea ice extent means that less sunlight gets reflected back into space and instead gets absorbed by the sea surface, resulting in higher sea surface temperatures. 

Surface temperature

The image below shows the October 2025 temperature anomaly from 1951-1980. Anomalies are very high, exceeding 10°C in areas over both the poles.


The image below shows monthly surface temperature anomalies from 1951-1980 through October 2025, when the anomaly was 1.37°C. 

Note that the 1951-1980 base isn't pre-industrial. When using a genuinely pre-industrial base, the temperature anomaly will be much higher, well above the thresholds that politicians pledged at the Paris Agreement wouldn't be crossed. 

Ominously, anomalies have kept rising over the past few months, and this occurred in the absence of El Niño conditions in 2025. 

Sea surface temperature

The image below shows monthly sea surface temperature anomalies from 1951-1980 through September 2025, when the anomaly was 0.74°C. The image also shows that the anomaly in September 2023 was 0.901°C. 


The image below shows the standard deviation from 1951-1980 of the monthly sea surface temperature through September 2025, when it was 8.045σ. The image also shows that the standard deviation in August 2023 was 10.148σ. 


In statistics, the empirical rule states that in a normal distribution, 68% of the observed data will occur within one standard deviation (1σ), 95% within two standard deviations (2σ), and 99.7% within three standard deviations (3σ) of the mean. A 4σ event indicates that the observed result is 4 standard deviations (4σ) away from the expected mean. In a normal distribution, 99.993666% of data points would fall within this range. The chance for data to fall outside of 4σ is thus infinitesimally small.

Meanwhile, sea surface temperatures have remained very high. The image below shows sea surface temperature anomalies from 1981-2011 in the Northern Hemisphere, with anomalies as high as 9°C or 13.6°F visible in the path of the Gulf Stream (at the green circle). 


ENSO outlook, next El Niño likely to be devastating

[ click on images to enlarge ]
The low global sea ice and the high sea surface temperatures paint a terrifying prospect. In the absence of El Niño conditions in 2025, temperatures have been suppressed, yet temperatures have been very high and may accelerate dramatically with the development of El Niño in 2026.

The outlook on the right, issued in October 2025, shows La Niña favored to persist through December 2025-February 2026, with a transition to ENSO-neutral likely in January-March 2026 (55% chance).  

ENSO (El Niño-Southern Oscillation) has three states: El Niño (when temperatures are higher than average), La Niña (when temperatures are suppressed), and a neutral state. 

The image on the right, adapted from a November 2025 NOAA image, gives an ENSO outlook (CFSv2 ensemble mean, black dashed line) that favors La Niña to persist into the early Northern Hemisphere winter 2025-26, implying that temperatures will remain suppressed until early 2026.

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

Temperatures in the Niño 3.4 area (5°N-5°S, 120-170°W) are critical to El Niño/La Niña development. The image below shows strongly negative sea surface temperature anomalies (SSTA vs 1991-2020, NOAA OISST v2.1 data) in the Niño3.4 area in the Central Pacific region, with a -0.8°C anomaly on November 6, 2025, while the inset also shows global SSTA. 


NOAA considers La Niña conditions to occur when the Niño3.4 OISST departures meet or exceed -0.5ºC along with consistent atmospheric features. These anomalies must also be forecasted to persist for 3 consecutive months. The graph below uses CDAS (Climate Data Assimilation System) data showing an anomaly of -1.129ºC on November 8, 2025.


The CDAS analysis below shows very low sea surface temperature anomalies in the Niño3.4 area on November 8, 2025. 


The CanSIPS forecast for March 2026 below shows high sea surface temperature anomalies in the central Pacific Ocean, indicating development of the next El Niño. The low sea surface temperature anomalies around Antarctica indicate areas where heavy melting will likely have taken place by March 2026. 


Antarctic sea ice

Currently, sea ice is 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 combination image below shows Antarctic sea ice concentration on November 7, 2025 (left) and Antarctic sea ice thickness on November 7, 2025 (right). 


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 a developing El Niño is strengthening the danger. Ominously, the forecast of sea surface temperature anomalies for August 2026 below looks grim. 


The methane danger

This increases the danger that massive amounts of methane will erupt from the seafloor in 2026, further accelerating the temperature rise.

The methane danger is further illustrated by the images below. The image directly below shows methane as high as 2620 parts per billion (ppb) recorded by the NOAA 20 satellite at 487.2 mb on November 5, 2025 AM.


The image below shows hourly methane measurements well above 2400 ppb. The image is adapted from an image issued by NOAA November 9, 2025, showing methane hourly averages recorded in situ at the Barrow Atmospheric Baseline Observatory (BRW), a NOAA facility located near Utqiaġvik (formerly Barrow), Alaska, at 71.32 degrees North latitude.


The image below is a similar image, this time showing that the monthly average methane recorded at the same station is about 2050 ppb. 


In the video below, Guy McPherson discussed our predicament. 



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

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

• Climate Reanalyzer

• ECMWF charts
https://charts.ecmwf.int/products/seasonal_system5_nino_annual_plumes

• Tropicaltidbits
https://www.tropicaltidbits.com

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

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

• Focus on 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, October 17, 2025

Antarctic sea ice in danger

The Antarctic sea ice area was 12.54 million km² on October 17, 2025, the second lowest daily area (behind 2023) and a deviation from 1981-2010 of -4.15σ.


This low Antarctic sea ice area is alarming. Antarctic sea ice typically reaches its annual low in February. The record low of 1.09 million km² that was reached on February 24, 2023, was very close to a Blue Ocean Event, yet the deviation then was only -2.86σ.

High temperature anomalies over Antarctica and high sea temperatures are behind the low sea ice area. The image below shows how much higher the September 2025 temperature was than it was in 1951-1980.

[ from earlier post ]
At this time of year, little sunlight is reaching the South Pole yet, so temperatures over Antarctica are still well below zero °C. Nevertheless, temperature anomalies were high in September 2025 and anomalies were as high as +4.22°C compared to 1979-2000 on October 14, 2025, which is remarkable given the absence of El Niño conditions. Record high daily temperatures were reached on each day of the period from 12 to 17 October 2025. The inset shows high polar temperature anomalies versus 1991-2020 on October 17, 2025.

[ click on images to enlarge ]
Meanwhile, Arctic sea ice volume remains at a record daily low, as it has been for more than a year, as illustrated by the image below. This contributes to low global sea ice, as this causes less sunlight to be reflected and instead more sunlight to be absorbed by the ocean surface. 


The global sea ice area was 3.45 million km² lower than 1981-2010 on October 17, 2025, a deviation from 1981-2010 of -4.47σ, as illustrated by the image below.


The image below shows Antarctic sea ice concentration on October 17, 2025.


The image below shows Antarctic sea ice thickness on October 17, 2025.


The situation is dire. An Antarctic Blue Ocean Event (sea ice approaching a low of one million km²) could occur in February 2026, triggering an Arctic Blue Ocean Event later in 2026.   

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.


Transform Society with the Climate Plan

[ image from this 2019 post, text discussed in earlier posts such as this 2022 one and links below ]

The Climate Plan calls for Transformation of Society in at least four sectors, as follows:

1. Energy - Generate clean, renewable energy with solar panels, turbines and batteries.

2. Food - Produce vegan-organic food and pursue synthetic food, solar food and precision fermentation.

3. Waste management - Pyrolyze organic waste with the biochar added to the soil.

4. Construction and Activities - Transition to online work, ordering, education and health diagnosis, using wood and green steel to construct buildings, vessels, bridges and water storage, while adding olivine sand to footpaths, bikeways, paths, gardens, beaches, forests and water bodies, and while letting eVTOL air taxis add extra mobility, battery exchange and mobile communications, in support of microgrids, WiFi, microwave and laser links.

The above transitions will help increase forests, as discussed in posts such as this one. Reforestation and afforestation efforts work best when including restoration of wildlife and creation of food forests as discussed in this post and in this post. A recent study led by Evan Fricke finds that with healthy populations of animals that disperse seeds, tropical forests can absorb up to four times more carbon. A 2024 study led by Maddi Artamendi finds a notable negative impact of reduced pollinator species diversity on plant reproductive success measures, such as seed set, fruit set and fruit weight. 

The images below illustrate the decline over time of wild mammals and birds, compared to humans, livestock and poultry. 


Further Links

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

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

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

• Focus on Antarctica
https://arctic-news.blogspot.com/2025/09/focus-on-antarctica.html

• Emissions and Temperature Rise
https://arctic-news.blogspot.com/2025/10/emissions-and-temperature-rise.html

• Seed dispersal disruption limits tropical forest regrowth - by Evan Fricke et al. (2025) https://www.pnas.org/doi/10.1073/pnas.2500951122

and
• Loss of pollinator diversity consistently reduces reproductive success for wild and cultivated plants - by Maddi Artamendi et al. (2024)
https://www.nature.com/articles/s41559-024-02595-2
discussed on Facebook at: 
https://www.facebook.com/groups/climateplan/posts/25746278341642263

• Wild mammals make up only a few percent of the world’s mammal biomass - by Hannah Ritchie (2022)





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