NETs range from afforestation to bioenergy with carbon capture and storage. They are seen by many as instrumental in achieving the mitigation objectives of the Paris Agreement. However, uncertainty remains regarding the technical, economic, and political feasibility of the large-scale deployment of NETs. The focus in this chapter is on whether a state may lawfully presume, for instance in the course of determining its long-term low-greenhouse-gas-emission development pathway under Article 4(19) of the Paris Agreement, that a future large-scale deployment of NETs will be realized. Gareth Davies maintains that that makes perfect sense, not least because conventional mitigation methods are in the same boat (of uncertainty), and that in other respects as well conventional methods are on a continuum with NETs. By contrast, Duncan McLaren and Wil Burns argue that any heavy reliance now on a presumed large-scale availability of NETs in the future would be irresponsible, unethical, and unlawful.

NETs range from afforestation to bioenergy with carbon capture and storage. They are seen by many as instrumental in achieving the mitigation objectives of the Paris Agreement. However, uncertainty remains regarding the technical, economic, and political feasibility of the large-scale deployment of NETs. The focus in this chapter is on whether a state may lawfully presume, for instance in the course of determining its long-term low-greenhouse-gas-emission development pathway under Article 4(19) of the Paris Agreement, that a future large-scale deployment of NETs will be realized. Gareth Davies maintains that that makes perfect sense, not least because conventional mitigation methods are in the same boat (of uncertainty), and that in other respects as well conventional methods are on a continuum with NETs. By contrast, Duncan McLaren and Wil Burns argue that any heavy reliance now on a presumed large-scale availability of NETs in the future would be irresponsible, unethical, and unlawful.

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 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.