Javier Lillo Ramos

An international team has analyzed sea surface temperatures in the Atlantic Ocean and at various points in the Mediterranean Sea. The analysis, published by World Weather Attribution (WWA), shows that this year's temperatures have been extraordinary, both in their intensity and how early they have reached such magnitude. This behavior is not only having an ecological impact on marine life, the authors state, but could also exacerbate potentially destructive regional climate events like those that occurred in Valencia in 2024.

Two Copernicus services have independently confirmed that global sea surface temperatures have broken records for this time of year. Daily data from the Copernicus Climate Change Service exceeded the 2024 levels on 21 June, reaching 20.86 °C, higher than the 20.83 °C recorded in 2023 and 2024. Data from the Copernicus Marine Watch Service show temperatures of 21.0 °C on 21 June, beating the 2023 and 2024 records by 0.1 °C. This unprecedented warming is linked to the onset of El Niño (announced by the WMO and declared by NOAA on 11 June) and to record-breaking sea surface temperatures in the North Pacific; consequences are anticipated for weather patterns, the global climate and marine ecosystems.

A new study, based on oceanographic data collected by ships and robotic floating buoys over several decades, provides the first evidence that a warm mass of deep circumpolar water is approaching Antarctica, threatening the fragile ice shelves that border it from below. This warming in the Southern Ocean has implications not only for Antarctic ice melt and sea-level rise, but also for global heat regulation, carbon storage and the global climate system. The study is published in Communications Earth & Environment.

The transition zone between land and sea in glaciers is an indicator of their stability. An analysis of satellite measurements from 1992 to 2025 has shown that 77% of Antarctica’s coastline has experienced no change. The 23% that did see a reduction in area was concentrated in regions where deep troughs allow access to warmer waters and where the bed slopes inland. These include the Antarctic Peninsula, Wilkes and George V Lands, and West Antarctica, where retreat of this transition line ranged between 10 and 40 km. A total of 12,800 km² of ice has been lost —an area roughly equivalent to almost half the size of Galicia— most of it in West Antarctica. The results are published in the journal PNAS.

An international study, published in Science, has found that only 24% of the current glacier mass would be maintained if the world were to warm to 2.7°C, the trajectory set by current climate policies. In contrast, limiting warming to 1.5°C - the Paris Agreement target - would preserve 54% of the glacier mass.