Heat-trapping gas once frozen in Arctic ground is slowly leaking and warming the planet

Ted Schuur, an ecologist at Northern Arizona University, explained that as the Arctic warms four times faster than the rest of the globe, its previously frozen ground, or permafrost, is thawing. This thawing allows trapped methane and carbon dioxide, produced from decaying plants and animals, to escape into the atmosphere, warming the planet.

"There's three times as much carbon still frozen in permafrost than what's now in the air," Schuur said, emphasizing that this carbon release is one of climate change's "scary tipping points."

Permafrost, ground that stays frozen for at least two years and often for centuries, traps decaying matter, preventing it from turning into greenhouse gases. However, as the Arctic warms, this system is becoming unstable. Scientists project that by the end of the century, the release of previously trapped gases from permafrost will add nearly half a degree of warming, roughly equal to the warming from a major industrialized country or the whole of Europe.

While the Arctic helps Earth's carbon cycle by acting as a sink, capturing carbon from the air, this balance has shifted due to warming. Now, it is venting more heat-trapping gases than it absorbs, contributing to climate change rather than helping mitigate it. Permafrost thaw, along with other warming-induced emissions from fires and changes to wetlands and lakes, is likely to increase warming by 20% by the end of the century.