Workshop Motivation: Some quantity of active carbon dioxide removal from the atmosphere will likely feature in optimal climate policy to substitute for emissions reductions in hard-to-abate sectors or to reduce atmospheric concentrations after net zero. Among multiple approaches that can result in carbon dioxide removal are enhanced rock weathering (ERW) and ocean alkalinity enhancement (OAE), which share the goal of using acid-base reactions to draw carbon dioxide from the atmosphere. Both ERW and OAE are now mentioned and supported in climate policy of leading nations and are subject to rapidly advancing development and deployment by commercial proponents, yet many questions about ERW and OAE remain. Are reliable methods available with which to measure and verify the quantity of carbon dioxide removal incurred by a given ERW or OAE activity? How good is the understanding of non-GHG side-effects, both positive and negative? Are policymakers being informed by the latest science from these fields?

Workshop Objectives: This workshop will convene roughly thirty experts drawn from the academic environmental science community as well as from industry and government to discuss these important questions about ERW and OAE. The workshop will include “state of the art” presentations with Q&A to help participants form a common understanding of what is happening in these fields. It will then facilitate in-depth discussions focused on understanding, quantifying, and comparing the environmental benefits and side-effects or risks of ERW and OAE. The workshop will ask participants to help identify research topics which can address gaps in this knowledge and to differentiate the roles for academia, industry, and government. We will produce a short workshop summary for Eos or a similar publication.

Workshop Organizers:

Jess Adkins, Geoff Holmes, Clara Blättler