In this paper, I address the question of whether aerosol geoengineering (AG) ought to be deployed as a response to climate change. First, I distinguish AG from emissions mitigation, adaptation, and other geoengineering strategies. Second, I discuss advantages and disadvantages of AG, including its potential to result in substantial harm to some persons. Third, I critique three arguments against AG deployment, suggesting reasons why these arguments should be rejected. Fourth, I consider an argument that, in scenarios in which all available climate change strategies would result in net harm to persons, we ought to adopt that response to climate change which would result in the least net harm. I suggest that under ..