Johannes Quaas

Universität Leipzig

Solar radiation modification - scenarios, risks, challenges and prerequisites

Climate change progresses, with too little mitigation still to limit warming to within the bounds of the Paris agreement. There is thus an increasing debate about artificial cooling of the climate system to address some of the consequences of global warming. Different ideas are discussed in the scientific literature, including in particular emission of aerosols to the stratosphere (using volcanic eruptions as analogues) and emission of aerosols to the troposphere (using cloud seeding as a lever to enhance the radiative effect). All such suggestions come with substantial risks and challenges. In particular, multiple aspects of climate change are not addressed by solar radiation modification, and scientific knowledge of mechanisms is partly insufficient. There also prerequisites that should be fulfilled before such measures can be considered, including governance, monitoring and prediction tools.