The article mentions that:

> Stratospheric SO2 rains out of the atmosphere after a year or so, so unlike CO2 emissions it is relatively easy to control the dosing and the magnitude of the desired effect

Is this not true? I'm curious about where I can read more about research about the lifetime of atmospheric SO2.

Edit: The best source I could find about stratospheric SO2 was based on measurements after Pinatubo at

https://www.osti.gov/pages/servlets/purl/1439705

(https://doi.org/10.1002/2017JD027006)

I see that the concentration declined to roughly 1% after 180 days (Figure 7). Volcanic aerosols seem to last a bit longer but seem to go back to background around 4 years (Figure 10).