Arctic tundra has transitioned from being a carbon sink to a carbon source

Arctic tundra currently emits more carbon dioxide and other greenhouse gases than it absorbs. Rising temperatures due to climate change have changed the impact that ecosystems have on the Earth, shifting from helping the planet cool to warming it.

“This is a really profound change,” he says Twilamoon National Snow and Ice Data Center in Colorado. “Anthropogenic warming is now causing natural warming, which is irreversible on time scales of thousands of years.”