Solar Geoengineering: The Basics

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Solar geoengineering (also known as solar radiation modification or SRM) refers to large-scale ,intentional efforts to reflect more sunlight back into space to cool the planet and help counteract some climate change impacts. While SRM may reduce global temperatures and ease some climate burdens on vulnerable communities, it does not address all climate impacts.It also carries significant ecological and social risks that remain poorly understood.

How Would It Work?

SRM increases Earth’s reflectivity (“albedo”) to reduce the amount of solar energy absorbed by the
planet. Several approaches are being explored, including two major approaches:

Potential Risks and Benefits

SRM’s risks and benefits are complex. While this list highlights some key considerations, many uncertainties remain. Notably, SRM does not undo climate change or restore pre-industrial conditions. Instead, it would create a new climate with distinct benefits and risks, many still poorly understood.

Why Research Solar Geoengineering?

While SRM cannot address root causes of climate change, studying it is crucial to understanding its risks and potential benefits. Evidence suggests SRM could cool the planet, but its broader impacts remain uncertain. Research aims to evaluate whether SRM could help reduce the climate harms alongside emissions reductions and other strategies.
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Importantly, SRM could be implemented unilaterally due to its likely low cost, raising serious concerns. Leaving questions around risks and impacts unanswered is dangerous. A unilateral decision could disrupt regional climates, increase geopolitical tensions, and undermine international climate cooperation.

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