Ocean’s ability to absorb carbon is weakening as climate change intensifies, UN warns

The ocean absorbs around 30 per cent of human-caused carbon dioxide (CO₂) emissions and 90 per cent of excess heat trapped by greenhouse gases. But climate change has already reduced its capacity to absorb carbon by approximately six per cent, a new UN report warns ahead of the COP31 climate conference in November. The report was a collaboration between the UN’s environment agency, UNEP, and the UN climate secretariat, UNFCCC, which co-organises COP31. “For a long time the ocean has been doing us an enormous climate service, but that service is under increasing pressure,” Sara Traerup, lead author of the report, told UN News.Rising temperatures and changes in ocean chemistry, circulation and ecosystems are weakening its ability to absorb and store carbon, leaving more CO₂ in the atmosphere. And this process “can definitely accelerate” in the foreseeable future, Ms. Traerup warned. Bridging our knowledge gapA major challenge is the lack of reliable ocean monitoring data, particularly in the Southern and Indian Oceans, the Arctic and many coastal regions. The report therefore calls for stronger “ocean carbon intelligence” – using science, technology, data and local knowledge to bette...