Our planet is being transformed by climate disruption, with some of the worst impacts occurring in the ocean. Currently, most efforts to address climate change are focused on reducing emissions of greenhouse gases. While those efforts remain vital, they’re no longer enough. We must also clean up the “legacy” greenhouse gas pollution already in our atmosphere.
Ocean Visions believes that we may be able to harness the power of the ocean to restore the climate and the ocean itself. The ocean already holds more carbon than any other part of the biosphere and has the potential to contribute even more. The sheer scale of the ocean means that any marine carbon dioxide removal (mCDR) solutions proven to be viable and safe would have the potential to clean up billions of tons of CO₂.
A number of mCDR approaches are being explored—including artificial upwelling and downwelling.
Artificial downwelling refers to the downward transfer of surface water and carbon to the deep ocean. Downwelling could be induced by pumps, artificially cooling surface waters, or increasing salinity through thickening of sea ice. Artificial upwelling refers to pumping up cooler, nutrient-rich waters from the deep to stimulate phytoplankton activity and draw down carbon dioxide.
Artificial upwelling and downwelling is at the theoretical stage. None of these approaches have been tested and the overall CO₂ removal potential is low.
Because artificial upwelling and downwelling has not been pursued beyond a theoretical framework, environmental impacts are unknown. However, changing seawater temperature and salinity are likely to affect phytoplankton communities and influence primary production. In addition, temperature changes may influence weather and related needed infrastructure could contribute to marine debris if damaged.
Ocean Visions’ mCDR Community brings together stakeholders to advance the state of knowledge, build bridges across disciplines, and help the community move towards safe and equitable testing and piloting of the most promising marine CDR approaches.
Ocean Visions’ mCDR road maps provide overviews of potential technologies, obstacles they face, and first-order priorities needing attention to advance the field. The road maps are intended to catalyze global collaboration and engagement and will be updated and refined as advances emerge in science, technology, governance, and policy.
