Marine carbon dioxide removal (mCDR) can be a naturally occurring or mechanical, human assisted, process that helps increase the rate of carbon dioxide uptake into the ocean or storage of organic carbon away from contact with the atmosphere. Nature-based solutions can include habitat restoration or reservation while pH adjustments to sewage effluent waters can be an example of a human-assisted process.

U.S. federal agencies, academic researchers, industry, nonprofits and other entities are researching marine carbon dioxide removal (mCDR) to investigate their potential to mitigate the impacts of acidification and climate change. Approaches for mCDR, such as ocean alkalinity enhancement and deep ocean biomass sinking, may remove excess carbon dioxide from the atmosphere and store it for long periods of time in the ocean. Research is needed to better understand the effectiveness of these techniques for mitigating the impacts of climate change.