Signal Ocean heat uptake rising by 0.15 W/m2 per decade

Summary

The report observes that the framework represents climate change only through atmospheric carbon dioxide and radiative forcing, which do not show how energy accumulates and is distributed within the Earth system. A positive energy imbalance since at least the 1970s has kept the system absorbing energy, and the ocean has stored about 90 percent of that excess heat. Recent studies find that ocean warming is speeding up, with the rate of heat uptake rising steadily by about 0.15 W/m2 per decade over recent decades. Ocean heat content reached a record high in 2025. As ocean heat content keeps growing, the ocean's capacity to buffer climate change declines and the likelihood of long-term warming and non-linear change rises. The report puts forward upper ocean heat content, over 0 to 2000 metres, as a candidate control variable for ocean warming.