The sequestration of carbon dioxide underground or underwater may offer a means of mitigating some of the effects of human-caused climate change without the politically, economically, and socially difficult step of reducing greenhouse gas emissions. Scientists in Japan and South Korea are carrying out important in situ experiments in injecting carbon dioxide into underwater oil and gas fields. Engineers in Japan have also conducted field trials—the only ones in the world—on a technique for sequestering liquid carbon dioxide in deep ocean basins. Yet many questions remain about large-scale sequestration in ocean sediments and waters: How will liability issues be dealt with? How will sequestration projects fit into the framework of international treaties that govern the oceans and climate change issues? What are the potential environmental impacts? The proposed fellowship project would examine the science and policy questions surrounding large-scale carbon sequestration in and under the oceans, with a particular focus on the following: • What are the policy challenges (both international or intranational) regarding the ocean sequestration of carbon dioxide, whether in deep water or in geological formations? • How might other nations benefit from the experimental work currently being carried out in Japan and South Korea on geological disposal of carbon dioxide? • What might other nations learn from current tests in Japan of deep-ocean carbon sequestration? • What are the risks and benefits of geological or deep-water disposal of carbon dioxide, both to humans and the environment?