FANTASTiC | 24 March 2025 | 634.47 MB
Some manifestations of climate change are easy to visualize: glaciers melting, rising sea levels, catastrophic storms. Permafrost is not one of those things; it is sometimes referred to as an "invisible threat." Permafrost is any ground that remains frozen for at least 2 years. There are approximately 9 million square miles of area covered by permafrost in the Northern Hemisphere - nearly the size of the United States, China, and Canada combined. What happens when global temperatures rise and permafrost starts to thaw? It is estimated that permafrost holds nearly twice as much carbon frozen in the ground as exists in the atmosphere right now, so when it thaws it releases that carbon (among other gases). Carbon is a greenhouse gas that gets trapped in the atmosphere, leading to more global warming, creating a sort of vicious cycle. Hence, the invisible threat.