The Law of Enhanced Weathering for Carbon Dioxide Removal: Volume 2 – Legal Issues Associated with Materials Sourcing

By Romany M. Webb

Achieving the Paris Agreement’s goal of limiting the increase in global average temperatures to well below 2 degrees Celsius, and ideally to 1.5 degrees Celsius, 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.

The development of new, or expansion of existing, mines to extract silicate minerals and rocks could raise a variety of legal and other issues. The legal framework for mining on federal, tribal, and state-owned land is especially complex, with numerous permitting and other requirements. Many of those requirements were put in place to mitigate the environmental and other risks associated with mining activities and thus should not be eliminated or weakened. However, modest changes could be made to facilitate access to silicate minerals and rocks for use in enhanced weathering, without compromising environmental or other outcomes.

Sourcing silicate-based wastes, particularly mine tailings, for use in enhanced weathering could also be challenging. There is often significant uncertainty as to who owns mine tailing and restrictions on their transfer to third parties. These issues could, again, be addressed through modest changes to existing legal frameworks.

Read the paper The Law of Enhanced Weathering for Carbon Dioxide Removal: Volume 2 – Legal Issues Associated with Materials Sourcing in Columbia Law School's Scholarship Archive.