Scientists propose stratospheric aerosol injection to curb record ocean heatwaves

A prolonged heatwave across Western Europe in the summer of 2026 set new temperature records for June and drove ocean surface temperatures to historic highs outside polar regions, raising alarms about worsening marine heatwaves. Researchers headed by Dr Lala Kounta at Michigan State University employed the peer-reviewed ARISE-SAI climate-intervention simulator to explore stratospheric aerosol injection as a cooling strategy.

Their simulations indicate that injecting up to 11 million tons of sulfur dioxide annually could limit global warming to 2.5 °F, cutting ocean heat-wave intensity by 25 % and duration by 21 %; doubling the injection to 22 million tons could achieve a 2 °F limit with 75 % intensity and 80 % duration reductions. Most modeled benefits appear in the Southern Hemisphere, especially the tropical Atlantic, Indian, Arctic and South Atlantic oceans.

The study notes that while aerosols may lower temperatures, they do not address ocean acidification, so emissions cuts and carbon removal remain essential. The authors present aerosol injection as one tool among several needed to manage rising ocean heat.