For millennia, the Arctic-boreal zone (ABZ) has served as a frozen carbon trap, locking carbon in its permafrost. However, the region is rapidly transforming into a net carbon producer as climate change accelerates.
Warming temperatures and increasingly frequent wildfires in northern regions are eroding permafrost. According to an international team led by the Woodwell Climate Research Center, 34% of the ABZ now emits more CO₂ than it absorbs.
Arctic-Boreal Zone And Increasing Carbon
The region in question consists of snowy, coniferous forests, also known as Taiga, along with wetlands and tundra. As the region warms, more vegetation means more CO₂intake from photosynthesis but also more CO2 being released through plant and microbial respiration, now overtaking the carbon intake from photosynthesis. Increasing wildfires also affected the balance, further growing the carbon-producing acreage.
It may seem counterintuitive that more greenery could lead to more carbon. However, in a recent conversation with The Debrief, Brendon Rogers, a Woodwell Climate Research Center scientist, provided deeper insights into what is happening.
“Carbon storage in the system is kind of like the money in your bank account,” Rogers said. “You get money largely through income, and money goes out through bills and whatever else you spend on. So if you get a new job, that’s the greening, your salary goes up.”
“That’s great. But if, at the same time, you bought a larger house and you bought a boat, and you’re going on a bunch of vacations, and you’re spending more than that new income is generating, then your bank account is going to lose money, right?”
Many factors influence the increased “income” to “spending” ratio. For example, the relatively small size of plants in northern latitudes renders them incapable of absorbing the tremendous amounts of carbon released from the ground as the region thaws.
The ABC Flux Climate Change Database
The Woodwell team’s new research is the most current and comprehensive study on carbon fluxes in the ABZ ever assembled, with a data library called ABC Flux that is four times the size of earlier studies. The ABC Flux data set was generated across 200 study sites between 1990 and 2020, crucially allowing for understanding the year-round dynamics of these areas as well as recent shifts in climate and fire regimes.
“We wanted to develop the most current and comprehensive picture of carbon in the north, and to do that, we knew we needed to account for fire’s growing carbon footprint in this region,” said Dr. Anna Virkkala, a research scientist at the Permafrost Pathways initiative at Woodwell and lead author of the study. “While we found many northern ecosystems are still acting as carbon dioxide sinks, source regions and fires are now canceling out much of that net uptake and reversing long-standing trends.”
Upscaling Climate Change Data
The primary data collection tools for the ABC Flux project are EC towers. “They give us really good quality data. It’s what we’re focusing on to try to improve monitoring,” Rogers said. The towers are similar to weather stations but more narrowly focused on monitoring the exchange of carbon and methane between land and the atmosphere. How these numbers change is the “flux” recorded in the ABC Flux database. With this data in hand, the team begins “upscaling” to get a broader environmental picture by pulling in other data streams to address holes in their collection.
“You definitely have data gaps. We know we’re never going to cover the entire region with towers. That’s totally unfeasible,” Rogers explained. “What we rely on is if an observation is in a certain type of forest under this climate, with this type of soil, and we have another forest with similar climate and soil over there, we’re going to assume that it could be behaving similarly.”
“We have enough data to test those assumptions out. That doesn’t mean that there aren’t gaps. For example, Siberia is still a relatively large gap. You can’t just, for example, take an average of all the observations and say that’s what the region is doing, because you know that there are a lot of areas that are not covered,” Rogers added.
Continuing Research on Climate Change
ABC Flux represents both a significant milestone and a foundation for future research on climate change. The dataset is publicly available for download through a NASA website and has already gained popularity among researchers.
“There have been a lot of downloads of the database,” according to Rogers. “One thing that we’re using it for, and I know other groups are using it for, is process model development and validation,” he said. “Models like what a climate model or earth system model would have been, where you’re trying to represent these ecosystems, but from first principles. One of the main benefits is that you can project that out into the future, and that’s where we get our projections of what the ecosystems will do.”
“It’s really important when you’re building those models to be able to develop parameters and validate them against observations. A lot of these data were out there, but it took a lot of work to get them together. This is a really helpful database for people to use for model development because it’s all in one place. It’s user-friendly,” Rogers added.
Solutions That Involve Communities
Beyond advancing climate science, Woodwell Climate Research Center is focused on practical solutions. Despite the complexity of climate research, the fundamental answer remains the same: reducing human emissions.
“We have a lot of interest in informing policy, both on sort of mitigation and adaptation,” Rogers said. “And the first thing I always say, there are a lot of things we should be thinking about, but when we’re talking about climate change, warming in high latitudes, what these ecosystems are doing, you always have to go back to what the main driver is, and that’s human emissions of CO₂ and other greenhouse gasses, fossil fuel emissions. So the ultimate solution is always that, and we can’t take our eye off the ball.”
Woodwell has partnered with the US Fish and Wildlife Service to protect land in the Yukon Flats National Wildlife Refuge from wildfires. This collaboration integrates effective fire management with the needs of Alaskan Native communities.
“There’s only so much you can do. One area that I’m focused on, and some of our team are focused on, is looking at the wildfire problem,” Rogers added.
“We’ve been analyzing this, thinking about this, having a lot of conversations, understanding how could one do wildfire management differently to incorporate not only carbon and climate but also things that really aren’t accounted for now, but are big issues like smoke and human health or habitat and subsistence for Indigenous communities.”
“So that is exciting work,” Rogers said.
The paper, “Wildfires Offset the Increasing but Spatially Heterogeneous Arctic–Boreal CO2 Uptake,” appeared on January 21, 2025, in Nature Climate Change.
Ryan Whalen covers science and technology for The Debrief. He holds an MA in History and a Master of Library and Information Science with a certificate in Data Science. He can be contacted at ryan@thedebrief.org, and follow him on Twitter @mdntwvlf.