LAUSR

Significance Even if aggressive mitigation policies are implemented soon, climate change impacts will worsen in the coming decades. One proposed response is stratospheric aerosol injection (SAI), which would reflect a small amount of the sun’s energy back to space, thereby cooling the planet. This approach is broadly considered to be relatively inexpensive and straightforward to deploy, and global cooling could occur rapidly. However, on regional scales, internal climate variability is likely to dominate over SAI forcing. This means that in the decade after SAI is deployed, many regions of the world could locally experience even higher temperatures. Our study provides conceptual insight for the possible perception of the failure of SAI or other climate mitigation strategies.