Can artificial injection of sulphate aerosol to mitigate heatwaves save lives?

Climate change causes an increase in the frequency and severity of heatwave events that, in turn, harm human health, pose significant financial costs, and elevate the risk of human mortality. It is estimated that more than 1,300 people die each year in the United States as result of extreme heat events. Using the Community Earth System Model, we mimic a geoengineering intervention scenario by modeling artificial stratospheric sulphate aerosol injections. Once in the atmosphere, sulphate aerosol scatters incoming radiation and cools Earths surface temperatures with the intent being to mitigate some of the impact of extreme heat events on society. Yet injecting sulfate aerosols into the stratosphere poses its own set of risks and human costs. In this study we present impacts of different scenarios of stratospheric aerosol injections on precipitation, air quality, human health, and human mortality in the United States. In our analysis, we compare estimates of the human mortality of extreme heat waves with an estimate of the net mortality rate from sulfate aerosol injected into the stratosphere.