Intentional interventions in global physical, chemical, and biological systems on a massive scale are receiving increasing attention in hopes of reducing the threat of anthropogenic climate change. Known as climate engineering, or geoengineering, research is moving forward, but regulation remains inadequate, due in part to significant regulatory challenges. This essay asserts that key to overcoming these regulatory challenges is distinguishing between the two primary forms of climate engineering, and between deployment and research. One of climate engineering’s two primary forms, carbon dioxide removal, can largely be addressed through existing legal instruments. In the case of solar radiation management, the other primary form, focusing initially on research can bypass the geopolitical quagmire of deployment. Two other major challenges to developing regulation for solar radiation management research remain: establishing regulatory legitimacy, and developing an appropriate definition of research. Potential regulatory forms include centralized international legal instruments, fully or partially private transnational networks, and norms developed from the bottom up.

Reprinted in Environmental Law and Climate Change, Jonathan Verschuuren (Ed.), The International Library of Law and the Environment series (Edward Elgar, 2015).