Models show Pacific cloud brightening could weaken El Niño with Europe and Asia risks

Computer models in a Science Advances study indicate that artificially brightening clouds over the equatorial Pacific, timed early in an El Niño, could neutralize much of the pattern and blunt related temperature and precipitation impacts, phys.org reported. Lead author Jessica Wan of the University of Chicago and colleagues used a forecasting model on the 1997-1998 and 2015-16 El Niño events. The approach would spray sea salt from ships into the lower atmosphere over a large Pacific zone. Simulations worked best when started in June and continued through the following February, reversing many land impacts that flip under El Niño. The technology is not ready: even with better nozzles, the work implies roughly 2,400 ships for the required impact. Models also showed unintended consequences, including warming over Europe and Asia, and the team did not assess repeated long-term use. Wan framed shorter targeted geoengineering as a possible addition to climate responses while emissions cuts continue, citing prior research that Australia's 2019-2020 bushfire smoke brightened clouds and helped drive multi-year La Niña conditions. The paper is DOI: 10.1126/sciadv.adx3012.