Anthropogenic stratospheric aerosol injection would cool the planet, stop the melting of sea ice and land-based glaciers, slow sea level rise, and increase the terrestrial carbon sink, but produce regional drought, ozone depletion, less sunlight for solar power, and make skies less blue
There are plenty of other criticisms of SAI,[0] including the potential impacts on human health as well as smaller organisms that would be even more sensitive like insects and krill; the impacts on cloud formation patterns; disrupting seasonal weather patterns leading to widespread flooding or drought and more.
It’s important to note that even the advocates of SAI pretty universally acknowledge it as a necessary evil (even if we stopped emitting CO2 tomorrow we’d still have to take some measures like these to fight back against the runaway effects that have already begun). And those scientists that oppose it are generally of the opinion that the negative impacts would outweigh the positives. One thing both sides agree on though is that we definitely don’t know enough still
What’s missing from this discussion:
There are plenty of other criticisms of SAI,[0] including the potential impacts on human health as well as smaller organisms that would be even more sensitive like insects and krill; the impacts on cloud formation patterns; disrupting seasonal weather patterns leading to widespread flooding or drought and more.
It’s important to note that even the advocates of SAI pretty universally acknowledge it as a necessary evil (even if we stopped emitting CO2 tomorrow we’d still have to take some measures like these to fight back against the runaway effects that have already begun). And those scientists that oppose it are generally of the opinion that the negative impacts would outweigh the positives. One thing both sides agree on though is that we definitely don’t know enough still
[0] https://www.nature.com/articles/s41598-019-53595-3