This chapter debates the consistency of the deployment of Solar Radiation Management (SRM) with international law. SRM might help to counter global warming at relatively low cost, but it could also have substantial negative environmental impacts. Jesse Reynolds, reviewing all the relevant international treaties, as well as customary international law, argues that solar geoengineering could be consistent with international law. There is even some evidence, he argues, that solar geoengineering may be required by international law. Kerryn Brent reaches the exact opposite conclusion. She argues that solar geoengineering at scale would violate the no-harm rule and is prohibited by the UNFCCC and other treaties.

This chapter debates the relevance of customary law to climate law. In climate-law discussions, most attention focuses on the treaties (the UNFCCC, Kyoto Protocol, and Paris Agreement) rather than on custom. Views differ as to the relevance or applicability of customary international law to state responsibility for responding to climate change. Sandrine Maljean-Dubois makes the case that norms of customary international law can meaningfully be applied to climate change mitigation, Christopher Campbell-Duruflé, by contrast, argues that those norms are too vague to address the problem in any meaningful way. This debate has important implications for determining the level of mitigation ambition that states must implement.

This chapter debates the relevance of customary law to climate law. In climate-law discussions, most attention focuses on the treaties (the UNFCCC, Kyoto Protocol, and Paris Agreement) rather than on custom. Views differ as to the relevance or applicability of customary international law to state responsibility for responding to climate change. Sandrine Maljean-Dubois makes the case that norms of customary international law can meaningfully be applied to climate change mitigation, Christopher Campbell-Duruflé, by contrast, argues that those norms are too vague to address the problem in any meaningful way. This debate has important implications for determining the level of mitigation ambition that states must implement.

This chapter debates the consistency of the deployment of Solar Radiation Management (SRM) with international law. SRM might help to counter global warming at relatively low cost, but it could also have substantial negative environmental impacts. Jesse Reynolds, reviewing all the relevant international treaties, as well as customary international law, argues that solar geoengineering could be consistent with international law. There is even some evidence, he argues, that solar geoengineering may be required by international law. Kerryn Brent reaches the exact opposite conclusion. She argues that solar geoengineering at scale would violate the no-harm rule and is prohibited by the UNFCCC and other treaties.