National Geographic Society

Rainforests have been successfully branded as the lungs of the planet, but how do you talk about a place that, due to extreme seasonality, has for millennia breathed carbon in without fully exhaling? And what if that is about to change? To answer these questions, we need to better understand how, when, and why Arctic vegetation is changing – often by going to the field. 

• The Arctic is warming faster than anywhere else on Earth, and as organic carbon frozen in its soils thaws, that ‘breath’ accumulates. Scientists see signs of a great ‘sigh’, whereby thousands of years of accumulated carbon is at risk of being released back into the atmosphere. 

• Satellites reveal that the Arctic has also become greener over the past 40 years. This indicates widespread changes to vegetation, but historical satellite data alone doesn’t tell the full story. 

• Can shifting Arctic vegetation cover offset soil carbon release, or will it instead accelerate it? And what effect will this have on wildlife, wildfires, and beyond?