Showing posts with label extent. Show all posts
Showing posts with label extent. Show all posts

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 12, 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 combination image below highlights the October 2025 very high temperature anomalies (from 1951-1980), exceeding 10°C, hitting areas over both the poles.


The image below shows the global 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 at the Paris Agreement pledged 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. 

The image below shows the global temperature standard anomaly for the 12 months from November 2024 through October 2025. 


The image below shows the standard deviation (Sd) anomalies from 1951-1980 of Arctic temperatures over the past few years, with a Standard Anomaly of 6.68σ reached in October 2025. 

The image below shows the standard deviation (Sd) anomalies from 1951-1980 of Arctic temperatures over the past few years, with a Sd of 4.59σ reached in October 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). 


Wild weather 

Wild weather strikes the world in many places. More than 1.4 million evacuated as second typhoon in a week slams into the Philippines, reports CNN. 

The image on the right shows temperature anomalies higher than 24°C at 2m in an area over Greenland on November 13, 2025.

The image below shows strong wind over Baffin Bay boosting temperatures over Greenland to as high as 8.6°C or 47.5°F at 1000 hPa on November 13, 2025, as strong wind pushes warm air over Greenland, while cold Arctic air gets pushed down toward England. 


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, NOAA OISST v2.1 data) in the Niño3.4 area in the Central Pacific region, with a -0.87°C anomaly versus 1991-2020 on November 8, 2025, while the inset also shows global SSTA that day. 


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 -1.161ºC on November 9, 2025.


The CDAS analysis below shows very low sea surface temperature anomalies in the Niño3.4 area on November 9, 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 10, 2025 (left) and Antarctic sea ice thickness on November 10, 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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Wednesday, September 3, 2025

Arctic sea ice September 2025

The image below shows Arctic sea ice concentration on September 9, 2025. 


Over the years, the global monthly sea ice concentration has fallen significantly (compared to 1951-1980). The image below shows the global monthly sea ice concentration anomaly through August 2025. 


Albedo loss due to very low global sea ice area

The global sea ice area was 2.50 million km² below the 1981-2010 mean on September 10, 2025, a deviation from 1981-2010 of -4.32σ. 


The above image shows the situation through September 9, 2025. It is significant that the global sea ice area anomaly has been strongly negative this year, even despite the absence of an El Niño.

Sea ice decline can occur by reduction in the area covered by the sea ice, resulting in albedo loss. Sea ice decline can also occur as the sea ice darkens, which can occur due to melting, cracking and thinning of the ice, due to rain and meltwater forming pools on top of the ice, due to growth of algae and due to settling down of aerosols on the sea ice, all of which will also result in albedo loss.

Loss of sea ice area results in albedo loss, which means that less sunlight gets reflected back into space and more heat instead gets absorbed by the ocean.

[ image from earlier post ]
Arctic sea ice thickness and volume

Sea ice decline also occurs as a result of thinning of the sea ice. The image on the right shows Arctic sea ice thickness on September 11, 2025. 

Sea ice thickness can be hard to measure, due to rain and meltwater forming pools on top of the ice, while clouds can also obscure satellite imaging.

On the image below, adapted from dmi.dk, markers are added for September (red) and April (blue) corresponding with the year's minimum- and maximum volume, showing the downward path over the years for both the annual sea ice volume minimum and maximum. Magenta bars are added in years when the melting volume from April to September was large, while green bars are added in years when it was small. 


Arctic sea ice volume in April 2025 was about 19,000 km³, which raised fears that virtually all Arctic sea ice could disappear in September 2025, resulting in a Blue Ocean Event. 

Meanwhile, sea ice volume has fallen to about 4,000 km³ on September 12, 2025, as illustrated by the image below. Arctic sea ice volume was at a record low for the day on September 15, 2025, as it has been for more than a year. 

Why a Blue Ocean Event is so dangerous

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.

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.

[ 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.

The image below, adapted from an image issued by NOAA on September 16, 2025, shows 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, adapted from Copernicus, shows a methane forecast for September 6, 2025 12:00, run that day at 00 UTC. High methane levels are visible on the West Coast of Canada, also discussed on facebook. 


The image below shows that the NOAA 21 satellite recorded methane levels as high as 2559 parts per billion (ppb) at 399.1 mb on September 6, 2025 AM.


High temperatures and ocean heat

In August 2025, high temperature anomalies (compared to 1951-1980) were recorded at both poles, as illustrated by the image below. 


The image below shows the NASA August 2025 temperature anomaly (versus 1951_1980). 

Ominously, the global temperature anomaly has gone up again recently, despite the current absence of an El Niño. The anomaly for August 2025 was 1.51°C above 1903-1912 (not pre-industrial), as illustrated by the image below. 


The image below shows temperature anomalies from 1951-1980 (NCEP/NCAR data). 

The image below shows sea surface temperature anomalies through August 2025 (ERA5 Data). 

The image below shows NASA land-only anomalies from 1880-1920 (not pre-industrial) through August 2025, when the anomaly was 1.82°C. The red line is a 3-year Lowess Smoothing trend. If this trend continued unchanged (dashed red), the anomaly could cross 3°C in 2029, causing mass extinction.


Note that when using a genuinely pre-industrial base, anomalies can be much higher than depicted in the above images. A 3°C anomaly constitutes an important threshold, since humans will likely go extinct with such a rise. As illustrated by the image below, the rise may already be more well over 2°C, while we may face a potentially huge temperature rise over the next few years.
[ 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, as discussed in the earlier post When Will We Die?

The image below shows Arctic air temperature through September 5, 2025, with the inset highlighting the Arctic and the global temperature anomaly that day. The temperature in the Arctic reached a daily record high of 2.4°C on September 5, 2025, an anomaly of +2.46°C compared to 1979-2000.

The image below shows sea surface temperatures in the Gulf through September 7, 2025, when the sea surface reached a record daily high temperature of an average of 30.84°C, an anomaly of +1.53°C compared to 1982-2010, with the inset highlighting the Gulf and the global sea surface temperature anomaly that day. 


The image below shows high Ocean Heat Content in the Gulf through September 7, 2025. 

Equivalent Ocean Heat Content on September 8, 2025, is illustrated in the image below. 

The temperature of the ocean is very high in many areas, as illustrated by the image below. The image below shows sea surface temperatures around North America as high as 33°C on September 1, 2025.

In conclusion, a lot of ocean heat is still on its way toward the Arctic Ocean along the path of the Gulf Stream. 

The Jet Stream is getting increasingly distorted, which threatens to - at times - speed up the flow of large amounts of heat into the Arctic Ocean. The image below shows the situation on September 10, 2025.

The image on the left shows the Jet Stream following the path of the Gulf Stream over the North Atlantic, with one branch going south and moving backward, while another branch is moving North over the Arctic Ocean, with both branches displaying circular patterns. 

The image on the right shows the Jet Stream reaching speeds over the Arctic Ocean as high as 253 km/h with wind power density as high as 67.9 kW/m² (at the green circle). 


Land Evaporation Tipping Point

Higher temperatures come with stronger feedbacks, such as stronger evaporation resulting in both a lot more water vapor and a lot more heat getting transferred from the surface to the atmosphere. Much of this will return to the surface with precipitation such as rain and snow, but 7% more water vapor will end up in the atmosphere for every degree Celsius rise in temperature. Moreover, water vapor is a potent greenhouse gas that will increase temperatures and it is a self-amplifying feedback that can strongly contribute to further acceleration of the temperature rise.

Precipitable water can be expressed in kg/m² or in millimeters (mm), with the latter representing the depth of the water if all the atmospheric vapor were condensed into liquid form and spread across the surface, while kilograms per square meter (kg/m²) represents the mass of that water per unit area (1 kg/m² = 1 mm). As illustrated by the image below, the monthly precipitable water anomaly (in kg/m², versus 1951-1980) has increased over time, in line with rising temperatures. 

At the same time, the monthly total precipitation anomaly (versus 1951-1980) has decreased over time, as illustrated by the image below. 

This decrease in precipitation indicates that over time, less and less evaporation is taking place over land, in turn indicating that the Land Evaporation Tipping Point is getting crossed in areas where water is no longer available locally for further evapotranspiration, i.e. from all processes by which water moves from the land surface to the atmosphere via evaporation and transpiration, including transpiration from vegetation, evaporation from the soil surface, from the capillary fringe of the groundwater table, and from water bodies on land, as also discussed at this page and at this article on the Water Vapor-Pressure Deficit (VPD).

Once this tipping point gets crossed, the land and atmosphere will heat up strongly. Additionally, more water vapor in the atmosphere accelerates the temperature rise, since water vapor is a potent greenhouse gas and this also contributes to speeding up the temperature rise of the atmosphere (as also discussed on facebook here, here and here).

The image below, adapted from Copernicus, shows the global fall in relative humidity over land over time. 

[ image from Moistening Atmosphere ]

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

• University of Bremen - sea ice concentration and thickness

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

• PIOMAS - Arctic Sea Ice Volume Reanalysis 

• Climate  Reanalyzer

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

Also discussed on facebook at:
https://www.facebook.com/photo/?fbid=10172670654340161&set=p.10172670654340161

• University of Miami - Rosenstiel School - North Atlantic OHC
https://isotherm.rsmas.miami.edu/heat/weba/atlantic.php

• Brian McNoldy - Ocean Heat Content
https://bmcnoldy.earth.miami.edu/tropics/ohc
discussed on Facebook at:
https://www.facebook.com/groups/arcticnews/posts/10163172734849679

• 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

• NOAA - Global Monitoring Laboratory - Data Visualisation - flask and station methane measurements
also discussed on facebook at: 
https://www.facebook.com/groups/arcticnews/posts/10163179340334679

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

• nullschool.net

• When will humans go extinct?
https://arctic-news.blogspot.com/2022/02/when-will-humans-go-extinct.html

• Coupled, decoupled, and abrupt responses of vegetation to climate across timescales - by David Fastovich et al. (2025)
https://www.science.org/doi/10.1126/science.adr6700
discussed on Facebook at:
https://www.facebook.com/groups/arcticnews/posts/10162972980774679

• Arctic Blue Ocean Event 2025?
https://arctic-news.blogspot.com/2025/03/arctic-blue-ocean-event-2025.html

• Arctic Blue Ocean Event 2025? (update June 2025)

• Blue Ocean Event


• Climate Plan








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