Like all good superheroes, you’d never suspect that the sea otter has secret powers to help save the world. But the furry creatures play a crucial role in keeping sea urchin populations down, which in turn helps kelp forests thrive. Kelp absorbs carbon dioxide from the atmosphere, helping slow global warming. Thanks to the otters, according to a new study, the kelp can absorb 12 times more CO2 than if the otters weren’t abundant. More sea otters means less rapid climate change.

The study looked at 40 years of data on otters and kelp from the Pacific Ocean off the coasts of Canada and Alaska. They found that the otters and kelp can remove so much CO2 that if it were valued on the European Carbon Exchange, it would be worth $205-$408 million. The authors suggested that the carbon be sold to help protect otters and reintroduce them in certain areas.

Otters feed on kelp-eating urchins, allowing kelp forests to grow larger and absorb more carbon dioxide than in areas with small otter populations.

Like other plants, kelp absorbs CO2 through photosynthesis — but kelp happens to be especially good at it. When sea otter populations are too low, sea urchins tend to eat too much kelp. A healthy sea otter population keeps everything in check.

Other animals have an influence on the carbon cycle, too, according to the study’s authors. In some cases, the impact may be large. But right now, animals aren’t included in climate change models. While increasing animal populations won’t solve the problem of global warming, the role that animals play is important. Restoring and protecting animal populations can help ecosystems sequester carbon more effectively.

The paper, written by scientists from University of California Santa Cruz, San Diego State University, University of Washington and University of Alaska, will be published in the October issue of Frontiers in Ecology and the Environment. Funding came from the National Science Foundation and the National Oceanic and Atmospheric Administration.

Main photo credit: mikebaird/Flickr; secondary photo credit: jimg944/Flickr