Albedo response of surface ocean to marine carbon dioxide removal

Establish how modifications to surface ocean waters produced by marine carbon dioxide removal—specifically ocean alkalinity enhancement through the addition of alkaline materials to surface waters—affect the ocean surface albedo, determining the direction and magnitude of albedo change under realistic deployment scenarios.

Background

Marine carbon dioxide removal (mCDR) includes proposals to modify ocean chemistry via ocean alkalinity enhancement and other interventions. The ocean’s low baseline albedo and potential brightening due to added minerals or biological changes suggest SAM effects could accompany mCDR, but the net albedo response remains uncertain.

The authors note that understanding how changes to surface waters alter albedo is essential to evaluating the overall climate forcing of mCDR, as SAM could amplify or offset the benefits of CO2 removal depending on the sign and magnitude of albedo changes.