Arctic News: 2025

Friday, September 19, 2025

Double Blue Ocean Event 2026? (update)

Arctic sea ice looks set to continue to be at record daily volume, as it has been for more than a year. The image below shows Arctic sea ice volume through September 19, 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.

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 18, 2025.

Ominously, the Antarctic sea ice area anomaly has been very low this year. The image below shows the 2025 anomaly (in black) from April through September 18, 2025, a period during which very little sunlight has reached the Southern Hemisphere. Furthermore, the low anomaly has been reached in the absence of an El Niño.

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 19, 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. </ div>

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

Thursday, September 18, 2025

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. 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).

An Antarctic Blue Ocean Event early 2026 would further accelerate the 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

Sunday, September 14, 2025

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 +0.78°C on September 18, 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 ]

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

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.