The Arctic might be a methane time bomb—or not
Thawing permafrost in Noatak National Preserve in Alaska (NPS Climate Change Response/)We already have a narrow window of time to ward off the worst impacts of climate change. That could shrink even more if a previously-stable store of carbon is suddenly unleashed into the atmosphere. And a big store that many climate scientists are worried about is permafrost, the frozen soil that covers about a quarter of the northern hemisphere. In a 2018 Special Report, the Intergovernmental Panel on Climate Change warned that permafrost presents a huge uncertainty for our carbon footprint in the future. What underlies that uncertainty is the fate of the old carbon stored in permafrost. Much like burning fossil fuels, releasing carbon from frozen soil that has been stored in the earth for thousands of years can warm our planet rapidly. But scientists aren’t sure whether that carbon will be released mostly as carbon dioxide, or...