Solar geoengineering or solar radiation management refers to technologies that alter the Earth’s radiative balance by increasing reflection of incoming sunlight back into space, such as stratospheric aerosol injection or cirrus cloud thinning, to temporarily mask the warming effects of greenhouse gases. This may address climate change impacts by lowering global average temperatures, or through other localised mechanisms, such as minimising sea ice loss.
However, some of these methods pose risks, such as increased risks of drought in the Amazon and Sahel region, North Atlantic hurricane activity, changes to monsoon rainfall patterns and extreme winter rainfall over Europe. They also raise geopolitical challenges; for instance, some nations may object to solar geoengineering in the Arctic or some states may seek to weaponise techniques developed. The UK Advanced Research and Innovation Agency are funding a £56.8m research programme to build an evidence base to support the effective governance of emerging climate cooling approaches.
This POSTnote will summarise the available evidence of the risks posed by the different SRM technologies and the implications of these for creating governance research approaches researchers can understand and follow, which holds them accountable and builds public trust.