Even as the Trump administration weighs withdrawing the United States from the Paris climate agreement, a new scientific paper has documented growing fluxes of greenhouse gases streaming into the air from the Alaskan tundra, a long-feared occurrence that could worsen climate change.

The new study, published in the Proceedings of the National Academy of Sciences, suggests that frozen northern soils – often called permafrost – are unleashing an increasing amount of carbon dioxide into the air as they thaw in summer or subsequently fail to refreeze as they once did, particularly in late fall and early winter.

Frozen northern soils are unleashing an increasing amount of carbon dioxide. Credit:Bloomberg

"Over a large area, we're seeing a substantial increase in the amount of CO2 that's coming out in the fall," said Roisin Commane, a Harvard atmospheric scientist who is the lead author of the study. The research was published by 19 authors from a variety of institutions, including NASA's Jet Propulsion Laboratory and the National Oceanic and Atmospheric Administration.

The study, based on aircraft measurements of carbon dioxide and methane and tower measurements from Barrow, Alaska, found that from 2012-2014, the state emitted the equivalent of 220 million tonnes of carbon dioxide gas into the atmosphere from biological sources (the figure excludes fossil fuel burning and wildfires). That's an amount comparable to all the emissions from the US commercial sector in a single year.