ConocoPhillips' massive Willow project would emit 284 million metric tons of carbon dioxide over its 30-year lifetime.

The Artic landscape is changing at an unprecedented pace: in Sweden, Alaska and elsewhere entire towns and villages, houses half sunken into the ground, risk being moved to more stable ground, as the permafrost they had been built on shifts and melts. In the Canadian north, suitable houses have become so rare that apartment prices have skyrocketed, triggering a housing crisis. All around the Arctic, homes lay abandoned, the damage too severe. Roads and other vital infrastructure are at risk, too.

Infrastructure damage from thawing permafrost and coastal erosion are a major portion of the overall impact cost, at $250 million to $420 million per year between 2015 and 2060.

Set against the austere peaks of the Western Brooks Range, the lake, looked like it was boiling. Its waters hissed, bubbled and popped as a powerful greenhouse gas escaped from the lake bed.

Frequent burning over decades reduces the amount of carbon and nitrogen stored in soils of savanna grasslands and broadleaf forests, in part because reduced plant growth means less carbon being drawn out of the atmosphere and stored in plant matter.

Thanks to warming winters and thawing permafrost, Arctic soil microbes are churning out carbon dioxide well after the end of the growing season ends. This extra source of atmospheric carbon may accelerate a regional warming trend that is already twice as fast as the global average.