This talk by Peter McCarthy examines the complex and growing relationship between international climate law, particularly the Paris Agreement, and geoengineering. Drawing on his background as a U.S.-trained lawyer and climate law researcher, McCarthy explains how global temperature became the central metric of the Paris Agreement and why that choice matters. Using vivid, personal examples about how temperature can feel radically different depending on context, he shows that temperature is a deceptively simple but deeply complex target for governing the climate system.
McCarthy argues that the world is not on track to meet the Paris Agreement’s temperature goals, that the Agreement lacks enforcement power, and that its legitimacy depends on collective belief in its success. As the gap between climate commitments and reality grows, he suggests that solar geoengineering—particularly techniques like stratospheric aerosol injection that directly affect global temperature—may come to be seen not just as an option, but as a way to “plug” a temperature-shaped hole in the Paris framework. While not advocating deployment, he raises the troubling possibility that the future credibility of the Paris Agreement, and perhaps of international law itself, may one day depend on geoengineering—placing humanity in a deeply uncomfortable ethical and legal position. Peter McCarthy is a Ph.D. candidate at Sciences Po Law School who studies the governance, and lack thereof, of deliberate interventions in the climate system to mitigate the impacts of climate change. Before coming to Sciences Po, Peter went to the University of Virginia School of Law, from where he holds a J.D., and was admitted to the D.C. Bar. He also worked in the tech industry in his hometown of San Francisco for several years before going to law school, and he holds an A.B. from Harvard University, where he studied Human Developmental and Regenerative Biology. He is also an avid alpine climber, skier, and surfer who is always scheming his next expedition. This talk was given at a TEDx event using the TED conference format but independently organized by a local community. Learn more at https://www.ted.com/tedx
