Policy Brief: Governing Solar Radiation Modification

Current commitments made under the 2015 Paris Agreement on climate change are insufficient to keep global warming below 2°C, and according to the Intergovernmental Panel on Climate Change (IPCC), much greater ambition is necessary. In response, scientists and others are considering the viability of climate-altering technologies known as Solar Radiation Modification (SRM). These aim to reflect solar radiation (sunlight) back into space or allow more heat to escape Earth’s atmosphere in order to counter some of the effects of climate change by reducing the global temperature.

SRM technologies would not address the causes of climate change and so cannot be substitutes for reducing emissions or removing carbon dioxide from the atmosphere. At best, they might ‘buy time’ while those essential measures are accelerated. They include a range of technologies which vary significantly. They are mostly theoretical, but if ever deployed at scale, some could create large and potentially long-term risks and governance challenges.