Earth's Northern Permafrost Region Has Experts Worried. Here's Why

A new research, co-authored by NASA scientists details how and where greenhouse gases are escaping from Earth's permafrost region as the Arctic warms. The findings reveal that the region which has locked carbon underground for millennia was now being a "net source of greenhouse gas emissions". An international team of scientists, led by researchers at Stockholm University said the landscape was in flux and could have a serious impact on the health of the planet after tracking the emissions using ground-based instruments, aircraft, and satellites.

The study, undertaken as part of the Global Carbon Project's RECCAP-2 effort, found that between 2000 and 2020, the region took up a fraction more carbon dioxide than it released. The region's lakes and wetlands were strong sources of methane during the two decades.

Overall, the region has been a net contributor to global warming, largely due to other greenhouse gas, methane, which has a lifespan of 10 years but traps significantly more heat per molecule than carbon dioxide which can last hundreds of years in the atmosphere.

"We know that the permafrost region has captured and stored carbon for tens of thousands of years. But what we are finding now is that climate-driven changes are tipping the balance toward permafrost being a net source of greenhouse gas emissions," said Abhishek Chatterjee, a co-author and scientist at NASA's Jet Propulsion Laboratory in Southern California.

"This study is one of the first where we are able to integrate different methods and datasets to put together this very comprehensive greenhouse gas budget into one report," he added.

The researchers said, "unlocking a fraction of the carbon stored in permafrost could further fuel climate change". They also cautioned that extreme wildfires and heat waves remain major sources of uncertainty when projecting the future.

Also read | Frozen Time Bomb? Permafrost Thawing Below The Arctic Raises Alarm

What is permafrost?

Permafrost is ground that has been permanently frozen for anywhere from two years to hundreds of thousands of years. Earth's northern region, encircling the Arctic from Alaska to Canada to Siberia stores twice as much carbon as currently resides in the atmosphere.

However, temperatures in the Arctic are warming two to four times faster than the global average. The thawing permafrost is shifting the region from being a net sink for greenhouse gases to becoming a net source of warming.