Friday, October 17, 2025

Antarctic sea ice in danger

The Antarctic sea ice area was 12.64 million km² on October 16, 2025, the second lowest daily area (behind 2023) and a deviation from 1981-2010 of -4.07σ.


This low Antarctic sea ice area is alarming. Antarctic sea ice typically reaches its annual low in February. The record low 1.09 million km² was reached on February 22, 2023, representing a deviation from 1981-2010 of -3.03σ.

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.

 

As the image below shows, the temperatures recorded over Antarctica throughout September 2025 were higher than in most earlier years, while a record daily high temperature was recorded on October 10, 2025, a +3.62°C anomaly compared to 1979-2000. The inset shows high temperature anomalies versus 1991-2020 at both poles on October 10, 2025.



The global sea ice area was 3.36 million km² lower than 1981-2010 on October 16, 2025, a deviation from 1981-2010 of -4.24σ, as illustrated by the image below. 

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.