Climbing concentrations of carbon dioxide make it likely that humans will have to move some gases from the atmosphere into the oceans to prevent crippling effects of climate change, the National Academies said in a major report released yesterday.

It came after months of deliberation among top U.S. scientists who concluded that global efforts to reduce emissions, even if successful, “may not be enough to stabilize the climate.” The report identified six ways to capture and store carbon dioxide in the oceans, a controversial idea that the report said “will likely be needed.”

Potential methods include stimulating more plant growth in and around the oceans and manipulating ocean currents to draw CO₂ deep underwater.

The report by the National Academies of Sciences, Engineering and Medicine (NASEM) is cautiously written and points out that research for ocean-based CO₂ reductions has only recently begun. It noted that “showstoppers” could be ahead, including prohibitive costs and legal conflicts.

On the other hand, it pointed out that oceans cover 70 percent of Earth, and they already remove and store a “substantial fraction” of the CO₂ being released through burning fossil fuels and other human activities.