A third of the Arctic’s vast carbon sink now a source of emissions, study reveals

For millennia, Arctic ecosystems have acted as a deep-freeze for the planet’s carbon, holding vast amounts of potential emissions in the permafrost.

But ecosystems in the region are increasingly becoming a contributor to global heating as they release more CO2 into the atmosphere.

More than 30 percent of the region was a net source of CO2, rising to 40 percent when wildfires were included.