Solar Radiation Management (SRM) has been proposed as a last resort to limit global
warming to 1.5 °C. However, its use is controversial due to potential risks, such as
changes in precipitation. These risks, along with the benefit of cooling, would cross
national borders and be unequally distributed across regions, which raises important
ethical concerns about distributive and procedural justice. To inform socially
responsible decision-making on SRM deployment, it is important to consider public
opinion, particularly in the Global South, which is most vulnerable to both global
warming and SRM-related risks.
We conducted a cross-cultural study involving students (N = 4,583) and members of the
general public (N = 2,248) from 20 countries across all inhabited continents, including
the Global South and 'non-WEIRD' (i.e., non-Western, Educated, Industrialized, Rich,
and Democratic) countries in the Global North. Because public awareness of SRM is
typically low, participants were provided with balanced information on SRM, including
scientific arguments for and against its use and on its governance. We assessed
perceptions of how SRM's costs and benefits might be distributed across countries, as
well as evaluations of the justifiability of different deployment scenarios.
Across countries—and especially in the Global South—participants generally perceived
SRM's consequences as unevenly distributed. They viewed unilateral deployment by a
single country as the least justifiable and joint deployment by all or most countries as
the most justifiable. Moreover, the more uneven participants perceived the distribution
of SRM's consequences, the more they judged all deployment scenarios as unjustifiable.
This association was strongest for unilateral deployment and weakest for joint

deployment.
Our findings suggest that while joint deployment is viewed more favorably than
unilateral action, it cannot compensate for concerns about the perceived unfair
distribution of SRM's consequences.