Clouding the mind? Assessing the suicide impacts of solar radiation management in the United States

[Geoengineering News]

https://link.springer.com/article/10.1007/s42973-026-00273-5

Authors: Shinsuke Tanaka & Tetsuya Matsubayashi 

10 August 2026

Abstract

Solar radiation management (SRM) is increasingly discussed as a climate intervention strategy by reducing incoming sunlight, but its potential impacts on human well-being are poorly understood. We examine the mental health implications of SRM. Using nearly three decades of U.S. county-month data, we estimate causal impacts of anticipated long-term (climatic) and unanticipated short-term (weather) variations in sunlight and temperature—only the anticipated ones would be affected by SRM, making this distinction critical for evaluating its impacts. We find that sustained sunlight reductions significantly increase suicide rates, whereas climatic temperature effects are weak and negative. These estimates suggest that a 1.5 

C SRM scenario could lead to approximately 3.81 thousand additional suicides in the U.S. between 2030 and 2100 from reduced sunlight alone, rising to 16.32 thousand when including temperature effects, relative to no-SRM. These findings highlight the need to consider potential mental health risks when evaluating broader societal impacts of SRM.

Source: Springer Nature Link