Solar radiation management geoengineering and strict liability for ultrahazardous activities

Proposals to develop solar radiation management (SRM) geoengineering call into question the capacity of international law to govern innovative new technologies. Geoengineering is ‘the deliberate large-scale intervention in the Earth’s climate system, in order to moderate global warming'. Solar radiation management proposals are intended to offset global temperatures rises resulting from climate change by reflecting a small percentage of incoming solar radiation (sunlight). The most prominent proposal, stratospheric aerosol injection (SAI), is to deposit aerosols into the stratosphere to reflect or scatter light away from the Earth, mimicking the cooling effect produced by large volcanic eruptions. Stratospheric aerosol injection is promising in that it could rapidly reduce global temperatures for a fraction of the cost of conventional mitigation strategies. However, SAI deployment is likely to have detrimental transboundary and global environmental side effects. It is therefore important that SAI is governed at an international level, but at present there are no international agreements that specifically address SAI research or deployment.