The Law of Enhanced Weathering for Carbon Dioxide Removal

Abstract

Despite scientists’ dire warnings about the catastrophic impacts of climate change, the greenhouse gases that cause it continue to be emitted in substantial amounts. While there is no question that deep, across the board cuts in greenhouse gas emissions are essential, many scientists now agree that simply cutting future emissions will not be enough. It will also be necessary to remove previously-emitted greenhouse gases from the atmosphere. This paper explores one greenhouse gas removal technique—enhanced weathering—which involves spreading finely ground silicate rocks or other materials with similar chemical composition over land or ocean waters. The materials react with carbon dioxide in the atmosphere, sequestering it in mineral form (e.g., as limestone) on land or in the oceans. While further study is needed to fully evaluate the risks associated with enhanced weathering, initial research suggests that it could result in the long-term storage of large amounts of carbon dioxide, likely for centuries or millennia.

This paper examines the international and U.S. legal framework for enhanced weathering on land and in ocean waters. As the paper shows, there are currently no international or U.S. federal or state laws dealing specifically with enhanced weathering, but projects could be regulated under various general environmental and other laws. At the international level, potentially applicable instruments include the Convention on Biological Diversity, Convention on the Prevention of Marine Pollution by Dumping of Waste and Other Matter, and the United Nations Convention on the Law of the Sea. Domestically, projects could be subject to various provisions of the Clean Water Act, Clean Air Act, Resource Conservation and Recovery Act, and Marine Protection, Research, and Sanctuaries Act, among other statutes. Exactly when and how these statutes will apply remains uncertain. Much will depend on the specific design of each project, including where it is conducted, the materials used, and how they are applied to land or ocean waters. The paper identifies areas where new laws could be adopted, or existing laws revised, to reduce uncertainty and facilitate the development of enhanced weathering projects.

Keywords: climate change, negative emissions, greenhouse gas removal, carbon removal, enhanced weathering