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Achieving the Paris Agreement’s goal of limiting the increase in global average temperatures well below 2°C, and ideally to 1.5°C, above pre-industrial levels will likely require the removal of carbon dioxide from the atmosphere. This could be achieved in various ways, including by enhancing natural weathering processes in which carbon dioxide reacts with silicate-based rocks, eventually forming carbonate minerals (e.g., limestone). Research suggests that the amount of carbon dioxide sequestered through this natural process can be increased by grinding silicate-rich minerals (e.g., olivine) or rocks (e.g., dunite) to increase their surface area and then spreading the powder over land or ocean waters (a process known as “enhanced weathering”). Some researchers have also proposed using other silicate-based materials, including mine tailing and similar industrial wastes, in enhanced weathering.

Performing enhanced weathering at scale would require access to large amounts of silicate minerals, rocks, or other materials. This paper examines key U.S. federal and state laws governing the mining and processing of silicate-rich minerals and rocks and the sourcing of silicate-based wastes for use in enhanced weathering. Laws governing the conduct of enhanced weathering projects, both on land and in ocean waters, are analyzed in a separate paper by the author.


Environmental Law | Law