Climate Plan

▼

PAGES AT ARCTIC-NEWS BLOG

▼

Monday, June 2, 2025

Arctic Blue Ocean Event 2025? (update June 2025)

High temperatures

The image below shows the temperature anomaly (versus 1951-19801) for May 2025. The large difference in anomalies on and around Antarctica is striking, highlighting the predicament of the West Antarctic Ice Sheet.   


How large is the temperature rise now? In the image below, created with NASA data, the decade from 1903 through 1912 is used as a custom base, illustrating that temperature anomalies were 1.5°C or more above this base for the past two years, i.e. for each of the 24 consecutive months from June 2023 through May 2025. So, when using 1903-1912 as a reference, the temperature rise has clearly breached the 1.5°C threshold for the averaging period going back two years through May 2025. What is the best reference period or base against which the rise is to be measured? An earlier analysis suggests that the rise may be even higher when compared to a genuinely pre-industrial base. What averaging period is most appropriate in analyses that include the temperature rise to come? The issue is discussed below. 

  
In the above image, the red line (two-year Lowess Smoothing trend) shows a steep rise that, when extended, points at 2°C above this base (1903-1911) getting crossed in late 2026, implying both goals of the Paris Agreement have been breached, i.e. to limit the temperature increase to 1.5°C above pre-industrial and to limit it to well below 2°C. What type of trend is most appropriate in analyses that include the temperature rise to come? Using a Lowess Smoothing trend and extending that trend linearly into the future may not be the most appropriate way to go. 

The image below shows a polynomial trend, calculated over data from 24 months ago (June 2023) through May 2025, and extended 24 months into the future. It's a cubic trend indicating that the temperature rise may be 3°C in 2026 and 5°C in 2027. 
[ A 3°C rise in 2026 and a 5°C rise in 2027? - click on images to enlarge ] 
How bad could 3°C or 5°C be? The image below adds some perspective, it is from the 2019 post When Will We Die?


Would things look much better when calculating the temperature rise over a longer period?

When using only past data, the average anomaly for the period starting 12 months ago through May 2025 is 1.67°C, for the period starting 24 months ago through May 2025 it is 1.69°C. When using an averaging period starting 10 years ago through May 2025, the average rise is 1.41°C. 

Going back further in time can reduce the average, but such an analysis would incorporate unacceptable bias toward past data at the expense of the rise to come. Indeed, the rise to come should not be ignored by selecting an averaging period that only uses past data. Instead, it makes sense to look at both past data and projections into the future and to also take into account potential acceleration of the rise due to compound impact of feedbacks and further mechanisms, as discussed further below.

The image below uses a 20-year averaging period centered around the end of May 2025. If the temperature rise followed a cubic trend based on data going back one decade, the rise averaged over the entire period would be 5.79°C, while the rise would cross 5°C in late 2031 and would cross 8°C at the end of 2034.
[ click on images to enlarge ]
What if an even longer averaging period was used? In the image below, the inset is added to confirm that the temperature rise vs 1903-1912 has been 1.5°C or higher for each of the past 24 months. The trend in the image covers a 30-year averaging period, centered around the end of May 2025. The trend confirms indications that the temperature rise would be high and cross 8°C in 2037 and 10°C in 2039.
[ click on images to enlarge ]
In other words, the longer the averaging period, the more the trend will be based on (and may be biased toward) data going further back in the past when temperatures were lower and feedbacks were weaker. As temperatures rise over time, however, feedbacks are likely to get stronger. Furthermore, tipping points may get crossed and Black Swan Events may occur. As an example, crossing the clouds tipping point at 1200 ppm CO₂ could - on its own - push temperatures up by an additional 8°C globally, which may occur well before 2028 (as discussed further below) and such tipping points should not be ignored. Indeed, much depends on the strength and combined impact of feedbacks and further mechanisms that could accelerate the temperature rise, so the more reason to discuss them in more detail. 

There are many conditions contributing to even higher temperatures. Emissions and temperatures have recently been rising at a rate that is unprecedented in history. The temperature rise may accelerate further and there are many conditions, feedbacks and further mechanisms that point at further acceleration.  

Earth's Energy Imbalance has more than doubled in recent decades, and reached 1.8 W/m⁻² in 2023, twice the "best" estimate from the IPCC, after having more than doubled within just two decades, as illustrated by the image below, from Mauritsen, 2025).


Below is a video in which Paul Beckwith discusses the study led by Mauritsen. Paul's video has the title: 57 scientists (@46 institutions) co-author 4-page paper ignoring almost all James Hansen's EEI work. James Hansen attributes 1.05 W/m² of the albedo loss to the clouds feedback, 0.15 W/m² to the snow/ice feedback and 0.5 W/m² to changes in shipping regulations (aerosol forcing). James Hansen blames the IPCC for failing to warn about the impact of many feedbacks and further mechanisms that are causing albedo loss. Indeed, the IPCC keeps downplaying the dangers in many ways, such as by ignoring a potentially much higher historic temperature rise and rise to come. Paul Beckwith highlights that the 57 authors of the study are merely calling for a "robust and reliable capability to observe the energy imbalance", without calling for more effective climate action that includes an overhaul of the IPCC narrative.


Concentrations and emissions of greenhouse gases are high and rising. The image below shows recent carbon dioxide (CO₂) concentrations at Mauna Loa, Hawaii.


The image below shows monthly CO₂ at Mauna Loa, Hawaii.


Black Swan Event 1. Crossing the clouds tipping point

The image below shows the same monthly data, this time from May 2022 through May 2025, with a trend added that warns about 1200 parts per million (ppm) getting crossed in 2028. 

Crossing the clouds tipping point at 1200 ppm CO₂ could - on its own - push temperatures up by 8°C globally, in addition to the temperature rise caused by the extra CO₂ to reach the tipping point. Moreover, the clouds tipping point is actually at 1200 ppm CO₂e (carbon dioxide equivalent), so when taking into account the impact of growth of other gases, strengthening feedbacks and further mechanisms, this tipping point could be crossed much earlier than in 2028, potentially as early as in 2026. 

Crossing the clouds tipping point early could be regarded as a Black Swan Event. Black Swan Events are events that are unforeseen in climate models. Such events can suddenly and unexpectedly increase temperatures. While there have been many warnings about such events, they are typically ignored or minimized in climate models. In fact, many warnings about acceleration of the temperature rise are ignored in climate models. Ten black swan events are identified in this post. Since black swan events are inherently unforeseen in climate models, there is little or no discussion about them and there may be many more of them on the way than the ten that are mentioned here.

The situation is also dire regarding other conditions, i.e. concentrations and emissions other than CO₂ are also higher for further gases and aerosols (also fueled by fires and war), while sea ice is low, the Jet Stream is distorted, AMOC is slowing down and sunspots are high.

On top of this, there are numerous self-amplifying feedbacks that can dramatically accelerate the temperature rise and mechanisms are in progress that increase temperatures, such as reductions of aerosols that are currently masking the temperature rise. Not only are many of the feedbacks self-amplifying, strengthening feedbacks and changing conditions can also amplify each other, e.g. a freshwater lid can form at the surface of the North Atlantic and a distorted Jet Stream can combine with hurricanes to cause more ocean heat to get pushed toward the Arctic Ocean underneath this lid, and subsequently speed up sea ice loss and cause eruptions of methane from the seafloor of the Arctic Ocean.
[ formation of a freshwater lid at the surface of the North Atlantic ]
There are further tipping points, in addition to the above-mentioned clouds tipping point. Tipping points include loss of Arctic sea ice and loss of the latent heat buffer as Arctic sea ice disappears; crossing such tipping points can abruptly and strongly increase temperatures and thus trigger crossing of further tipping points. 

Black Swan Event 2. Early El Niño

Models do not predict the next El Niño to appear soon, as illustrated by the image below. Instead, NOAA expects La Niña to return in the Northern Hemisphere fall and winter 2025-26. 


Nevertheless, the next El Niño may emerge earlier, and it may be a strong El Niño. Over the past few months, there's been a zigzag pattern of rises and falls in sea surface temperatures in Niño 3.4, an area in the Pacific (inset) that is critical to the development of El Niño, as illustrated by the image below.


Black Swan Event 3. Low sea ice

One feedback of high temperatures and high concentrations of greenhouse gases is loss of sea ice. Polar amplification of the temperature rise is hitting the Arctic hard, and is also causing dramatic loss of Antarctic sea ice. Global sea ice area has been very low over the past few years, as illustrated by the image below, something that wasn't anticipated in climate models. Low global sea ice comes with dramatic loss of albedo, i.e. a lot of sunlight was in previous years reflected back into space and it is now instead getting absorbed by the sea surface. On June 2, 2025, global sea ice area was 17.52 million km², lowest on record for the day. 


Arctic sea ice extent is currently lowest on record for the day, as illustrated by the image below. On June 17, 2025, Arctic sea ice extent was 10.573 million km², lowest on record for the day.


Low sea ice can also be regarded as a Black Swan Event, the more so since there currently is no El Niño present, but instead ENSO-neutral conditions dominate. Importantly, low sea ice does increase ocean heat, as discussed next. 

Black Swan Event 4. Loss of lower clouds

Low global sea ice area comes with albedo loss and this causes more heat to be absorbed by oceans. Higher sea surface temperatures result in loss of lower clouds, further reducing albedo and thus accelerating the temperature rise. 


This extraordinary loss of albedo may result in a Blue Ocean Event in the course of 2025, as discussed next.

Black Swan Event 5. Blue Ocean Event 

On June 2, 2025, Arctic sea ice area was 2nd lowest on record for that day, only slightly higher than 2016. Significantly, 2016 was a strong El Niño year. On June 2, 2025, Arctic sea ice area was 0.44 million km² lower than on June 2, 2012. If the sea ice area will be 1.34 million km² less than 2012 on September 12 this year, there will be a Blue Ocean Event.  
[ from earlier post ]
Black Swan Event 6. Loss of latent heat buffer

Volume and thickness are two further measures to assess the health of Arctic sea ice, and they are critical in regard to the latent heat buffer, which decreases as sea ice, permafrost and glaciers disappear.

Latent heat is energy associated with a phase change, such as the energy consumed when ice turns into water. During a phase change, the temperature remains constant. As long as there is ice, additional heat will be absorbed by the process of ice turning into water, so the temperature doesn't rise at the surface.

[ from Albedo, latent heat, insolation and more ]
     [ Arctic sea ice volume, click to enlarge ]
The amount of energy absorbed by melting ice is as much as it takes to heat an equivalent mass of water from zero to 80°C. The energy required to melt a volume of ice can raise the temperature of the same volume of rock by as much as 150ºC.

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. 

     [ Arctic sea ice volume, click to enlarge ]
Similarly, there is a point beyond which thawing of permafrost on land and melting of glaciers can no longer consume heat, and all further heat will instead warm up the surface.

The image on the right shows that Arctic sea ice volume has been at a record daily low for more than a year, reflecting severe loss of the latent heat buffer.

Loss of the latent heat buffer constitutes a tipping point. Beyond a certain point, further ocean heat arriving in the Arctic Ocean from the Atlantic Ocean and the Pacific Ocean will no longer be able to be consumed by melting sea ice from below.

The combination image below shows Arctic sea ice thickness on April 28, 2025 (left), May 13, 2025 (center) and June 13, 2025 (right).

[ Arctic sea ice thickness, click on images to enlarge ]
The image below shows Arctic sea ice thickness on June 15, 2025. 
Black Swan Event 7. Seafloor methane eruptions

Further incoming heat therefore threatens to instead reach the seafloor of the Arctic Ocean and destabilize methane hydrates contained in sediments at the seafloor, resulting in abrupt eruptions of huge amounts of methane, in turn threatening increased loss of permafrost, resulting in additional emissions, as illustrated by the above image and the image below. 
[ The Buffer is gone, from earlier post, click to enlarge ]
The danger is especially large in the East Siberian Arctic Shelf (ESAS), which contains huge amounts of methane and which is hit strongly by the temperature rise, as described in earlier posts such as this one.

Methane in the atmosphere could be doubled in March 2026 if a trend unfolds as depicted in the image below. A rapid rise is highlighted in the inset and reflected in the trend, which is based on January 2023-October 2024 methane data, as issued in February 2025. 
[ Double the methane in March 2026? Image from earlier post, click on images to enlarge ]
A rise like the one depicted in the trend could eventuate as rising ocean heat destabilizes methane hydrates contained in sediments at the seafloor of the Arctic Ocean. The temperature rise in the Arctic would accelerate since the methane would initially have a huge impact over the Arctic and cause depletion of hydroxyl, of which there is very little in the atmosphere over the Arctic in the first place. Such a rise in methane would also dramatically increase concentrations of ozone in the troposphere and concentrations of water vapor in the stratosphere. 

The image below with high levels of methane recorded at Utqiagvik (Barrow), Alaska, should act as a warning. 
[ discussed on facebook here and here, click to enlarge images ]
Black Swan Event 8. Water vapor

The IPCC has failed to warn about the size of the temperature rise. Higher temperatures imply 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.

[ from April 2024 post, click on images to enlarge ]
As illustrated by the above image, the temperature rise from pre-industrial to February 2024 could be as large as 2.75°C, which corresponds with almost ⅕ more water vapor in the atmosphere. 

Water that previously remained present in the ground, is increasingly moving up into the atmosphere, since a warming atmosphere holds more water vapor and thus sucks up increasingly more water. The water vapor feedback results in more moisture getting sucked up into the air as temperatures rise, a process that is further accelerated by stronger wind as temperatures rise.

More transpiration from vegetation and more evaporation from rivers, lakes and the soil contributes to stronger drought and makes vegetation more vulnerable to pests & diseases and also makes both vegetation and the soil more prone to get burned. After fires, the soils turns black (reflecting less sunlight back into space) and is more vulnerable to erosion and to further droughts and fires, having lost the vegetation that previously held the soil together.

Trees keep the soil together with their roots and also keep the soil cool. Because of the lower temperatures, the soil will also retain more moisture. Trees cool the surface by shading it, by transpiration and by releasing volatile organic compounds into the air that contribute to the formation of clouds that reflect more sunlight back into space and that cause more rainfall. If rainwater can run deep down into the soil along the roots of trees, it helps replenish the groundwater.

The Land Evaporation Tipping Point can get crossed locally when 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.

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.
(discussed on facebook here, here and here).

Compound effect of several ignored Black Swan Events 

Black Swan Events may be unexpected and they are typically excluded from models that seek to downplay the dangers, but that doesn't mean that Black Swan Events should be ignored. Using non-linear trends may show unexpected things, but sometimes they can turn out - in hindsight - to be pretty accurate, as illustrated by the combination image below. 
[ screenshot from earlier post, click to enlarge ]
Several Black Swan Events can also combine with catastrophic results, as described below. 

Black Swan Event 9. Abrupt collapse of the West-Antarctic ice sheet

A recent study warns that collapse of the West Antarctic Ice Sheet (WAIS) could contribute over 4 m sea-level rise with little (0.25 °C) or even no ocean warming above present, even without additional carbon emissions. The study concludes that we are likely already at (or almost at) an overshoot scenario and adds that, once on the lower branch, WAIS recovery by tipping back to the upper branch occurs only once the ocean temperature cools between −1.25 and −1.5 °C below present.

In the video below, Paul Beckwith discusses the study. 


The very low Antarctic Sea Ice over the past few years was not anticipated by models, neither was the steep rise in sea surface temperatures. Continued loss of Antarctic sea ice could dramatically increase sea surface temperatures where the sea ice disappears. A further rise of global sea surface temperatures could make things worse. The joint impact could cause abrupt collapse of the West Antarctic Ice Sheet.

Black Swan Event 10. Fires and lightning

Emissions can increase strongly, abruptly and rapidly for many reasons, such as due to more burning of fossil fuel, forests, wood and other biofuel, and more vegetation starting to die due to droughts, heatwaves, pests and diseases, and decompose or burn due to fires. Peatlands, tar sands, rainforests and soil can all start to burn as temperatures keep rising. As temperatures rise rapidly, permafrost can release huge amounts of emissions, including carbon dioxide, methane and nitrous oxide.


The above image shows annual number of fires and area burned in Canada and is adapted from the Canadian National Fire Database, which adds that while lightning causes about 50% of all fires, it accounts for about 85% of the annual area burned. A 2022 study finds that increases in lightning ignition efficiency, together with a projected doubling of lightning strikes, result in a 39%–65% increase in lightning-caused fire occurrence per 1°C warming.

The combination of higher temperatures, stronger wind, higher vulnerability of forests and more lightning will cause more fires and more emissions of carbon dioxide, black carbon, brown carbon, methane, carbon monoxide and tropospheric ozone. At 3-8 miles height, during the summer months, lightning activity increases NOx by as much as 90% and tropospheric ozone by more than 30%. Tropospheric ozone has a direct warming impact as a greenhouse gas, while carbon monoxide can indirectly cause warming by extending the lifetime of methane. 

The worst wildfires can send smoke high enough to affect the ozone layer in the stratosphere. Damage to the ozone layer and climate change are forming a dangerous feedback loop.

Scientists are shocked to see sea ice disappear

In the video below, Guy McPherson reflects on news that scientists are shocked to see sea ice disappear.


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

• NASA - GISS Surface Temperature Analysis

• Earth's Energy Imbalance More Than Doubled in Recent Decades - by Thorsten Mauritsen et al. (2025)
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2024AV001636
discussed on Facebook at: 

• NOAA - Daily, Monthly and Weekly Average CO2

• NOAA - Global Monitoring Laboratory

• Clouds Tipping Point
https://arctic-news.blogspot.com/p/clouds-feedback.html

• Arctic Blue Ocean Event 2025?

• Sunspots
https://arctic-news.blogspot.com/p/sunspots.html

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

• 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

• NOAA - Climate Prediction Center - El Niño/Southern Oscillation (ENSO) Diagnostic Discussion
https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.shtml

• Pre-industrial
https://arctic-news.blogspot.com/p/pre-industrial.html

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

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

• NOAA - Office of Satellite And Product Operations - Sea Surface Temperatures
https://www.ospo.noaa.gov/products/ocean/sst/contour/index.html

• Jet Stream
https://arctic-news.blogspot.com/p/jet-stream.html

• Cold freshwater lid on North Atlantic
https://arctic-news.blogspot.com/p/cold-freshwater-lid-on-north-atlantic.html

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

• Accelerating Temperature Rise 
https://arctic-news.blogspot.com/p/threat.html

• Feedbacks (including the Water Vapor Feedback)
https://arctic-news.blogspot.com/2024/07/feedbacks.html

• Extinction
https://arctic-news.blogspot.com/p/extinction.html

• Antarctic Ice Sheet tipping in the last 800,000 years warns of future ice loss - by David Chandler et al. 
https://www.nature.com/articles/s43247-025-02366-2

• Future increases in lightning ignition efficiency and wildfire occurrence expected from drier fuels in boreal forest ecosystems of western North America - by Thomas Hessilt et al. (2022) 









at