Using geoengineering to cool the planet might create problems. Cloud seeding over the eastern Pacific and introducing aerosols into the stratosphere are two possibilities. But brightening marine clouds over the eastern Pacific could dramatically weaken the El Niño cycle, triggering major changes to global weather patterns, while stratospheric aerosol injection could leave the system largely unchanged.
news.ucsb.edu/2025/022027/hard-look-geoengineering-reveals-global-risks