Arctic sea ice extent was 8.35 million km² on July 4, 2025, a record low extent for this time of year. This record daily low extent is the more significant since it was reached in the absence of El Niño conditions. Instead, ENSO-neutral and borderline La Niña conditions are currently dominant.
Sea ice extent is one out of several measurements indicating the miserable state the Arctic sea ice is in, as also discussed in an earlier post. The image below shows Arctic sea ice concentration on July 6, 2025.
The combination image below shows Arctic sea ice thickness on July 4, 2025 (left) and sea surface temperature on July 5, 2025 (right).
Arctic sea ice volume was at a record daily low on July 5, 2025, as it has been for more than a year, as illustrated by the image below.
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[ from earlier post ] |
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[ Earth's albedo, image from Eliot Jacobson ] |
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[ James Hansen: Inferred contributions to reduced Earth albedo ] |
There is a compound impact in that sea ice loss comes with albedo loss that causes more heat to be absorbed by oceans, while higher global sea surface temperatures also cause further loss of lower clouds, further reducing albedo and thus accelerating the temperature rise.
Polar amplification of the temperature rise narrows the temperature difference between the poles and the Equator, which causes distortion of the Jet Stream that in turn results in more extreme weather events. A 2025 study led by Tselioudis suggests that this causes the band of clouds over the Tropics to contract. Since clouds over the Tropics reflect relatively more sunlight, this results in reduced global albedo.
The extraordinary albedo loss depicted in the above image causes the temperature to rise, increasing the probability for a Blue Ocean Event to occur in the course of 2025.

Talking about probabilities, the 2024 world 2m temperature standard deviation from 1951-1980 was very high, an anomaly of 11.157 σ, as illustrated by the above image. In statistics, the empirical rule states that in a normal distribution, 68% of the observed data will occur within one standard deviation (σ), 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. The 2024 temperature anomaly was an 11.157σ event.
Danger Assessment
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[ image from earlier post ] |
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
• National Institute of Polar Research Japan
https://ads.nipr.ac.jp
• 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