## [Wildfires Offset the Increasing but Spatially Heterogeneous Arctic–boreal CO2 Uptake](/resource/wildfires-offset-increasing-spatially-heterogeneous-arctic-boreal-co2-uptake) Organization [Northern Arizona University](/organization/northern-arizona-university) [Woodwell Climate Research Centre](/organization/woodwell-climate-research-centre) [University of Texas at Austin](/organization/university-texas-austin) [Alfred Wegener Institute](/organization/alfred-wegener-institute) [Humboldt University of Berlin](/organization/humboldt-university-berlin) [University of Alaska Fairbanks](/organization/university-alaska-fairbanks) [Met Office Hadley Centre for Climate Science and Services](/organization/met-office-hadley-centre-climate-science-and-services) [Korea University](/organization/korea-university) [California Institute of Technology](/organization/california-institute-technology) [University Paris-Saclay](/organization/university-paris-saclay) [Aarhus University](/organization/aarhus-university) [University of Oulu](/organization/university-oulu) [Columbia University](/organization/columbia-university) [Royal Netherlands Institute for Sea Research](/organization/royal-netherlands-institute-sea-research) [Vrije Universiteit](/organization/vrije-universiteit) [University of Copenhagen](/organization/university-copenhagen) [University of Alberta (UofA)](/organization/university-alberta-uofa) [University of Edinburgh](/organization/university-edinburgh) [Max Planck Institute for Biogeochemistry](/organization/max-planck-institute-biogeochemistry) [Linnaeus University](/organization/linnaeus-university) [Dalhousie University](/organization/dalhousie-university) [University of Montreal](/organization/university-montreal) [GFZ German Research Center for Geosciences](/organization/gfz-german-research-center-geosciences) [University of Hamburg](/organization/university-hamburg) [Swedish University of Agricultural Sciences](/organization/swedish-university-agricultural-sciences) [Russian Academy of Science](/organization/russian-academy-science) [Japan Agency for Marine-Earth Science and Technology (JAMSTEC)](/organization/japan-agency-marine-earth-science-and-technology-jamstec) [Wageningen University & Research](/organization/wageningen-university-research) [Greenland Institute of Natural Resources](/organization/greenland-institute-natural-resources) [San Diego State University](/organization/san-diego-state-university) [University of Helsinki](/organization/university-helsinki) [University of Eastern Finland](/organization/university-eastern-finland) [Forestry and Forest Products Research Institute](/organization/forestry-and-forest-products-research-institute) [Agroscope](/organization/agroscope) [Environment and Climate Change Canada (ECCC)](/organization/environment-and-climate-change-canada-eccc) [National Institute for Environmental Studies](/organization/national-institute-environmental-studies) [Meteorological Research Institute (MRI)](/organization/meteorological-research-institute-mri) [Korea Polar Research Institute (KOPRI)](/organization/korea-polar-research-institute-kopri) [University of Oslo](/organization/university-oslo) [University of Groningen](/organization/university-groningen) [Wilfrid Laurier University](/organization/wilfrid-laurier-university) [Technical University of Braunschweig](/organization/technical-university-braunschweig) [Osaka Metropolitan University](/organization/osaka-metropolitan-university) Resource Type [Peer reviewed article](/taxonomy/term/37) Author(s) Anna-Maria Virkkala Brendan Rogers Jennifer Watts Kyle Arndt Stefano Potter Isabel Wargowsky Edward Schuur Craig See Marguerite Mauritz Julia Boike Marion Bret-Harte Eleanor Burke Arden Burrell Namyi Chae Abhishek Chatterjee Frederic Chevallier Torben Christensen Roisin Commane Han Dolman Colin Edgar Bo Elberling Craig Emmerton Eugenie Euskirchen Liang Feng Mathias Göckede Achim Grelle Manuel Helbig David Holl Järvi Järveoja Sergey Karsanaev Hideki Kobayashi Lars Kutzbach Junjie Liu Ingrid Luijkx Efrén López-Blanco Kyle Lunneberg Ivan Mammarella Maija Marushchak Mikhail Mastepanov Yojiro Matsuura Trofim Maximov Lutz Merbold Gesa Meyer Mats Nilsson Yosuke Niwa Walter Oechel Paul Palmer Sang-Jong Park Frans-Jan Parmentier Matthias Peichl Wouter Peters Roman Petrov William Quinton Christian Rödenbeck Christian Rödenbeck Torsten Sachs Christopher Schulze Oliver Sonnentag Vincent Louis Eeva‐Stiina Tuittila Masahito Ueyama Andrej Varlagin Donatella Zona Susan Natali Original Authors Anna-Maria Virkkala Brendan Rogers Jennifer Watts Kyle Arndt Stefano Potter Isabel Wargowsky Edward Schuur Craig See Marguerite Mauritz Julia Boike Marion Bret-Harte Eleanor Burke Arden Burrell Namyi Chae Abhishek Chatterjee Frederic Chevallier Torben Christensen Roisin Commane Han Dolman Colin Edgar Bo Elberling Craig Emmerton Eugenie Euskirchen Liang Feng Mathias Göckede Achim Grelle Manuel Helbig David Holl Järvi Järveoja Sergey Karsanaev Hideki Kobayashi Lars Kutzbach Junjie Liu Ingrid Luijkx Efrén López-Blanco Kyle Lunneberg Ivan Mammarella Maija Marushchak Mikhail Mastepanov Yojiro Matsuura Trofim Maximov Lutz Merbold Gesa Meyer Mats Nilsson Yosuke Niwa Walter Oechel Paul Palmer Sang-Jong Park Frans-Jan Parmentier Matthias Peichl Wouter Peters Roman Petrov William Quinton Christian Rödenbeck Christian Rödenbeck Torsten Sachs Christopher Schulze Oliver Sonnentag Vincent Louis Eeva-Stiina Tuittila Masahito Ueyama Andrej Varlagin Donatella Zona Susan Natali Contacts [Anna-Maria Virkkala](/contact/anna-maria-virkkala) Resource Date: 2025 The Arctic–Boreal Zone is rapidly warming, impacting its large soil carbon stocks. Here we use a new compilation of terrestrial ecosystem CO2 fluxes, geospatial datasets and random forest models to show that although the Arctic–Boreal Zone was overall an increasing terrestrial CO2 sink from 2001 to 2020 (mean ± standard deviation in net ecosystem exchange, −548 ± 140 Tg C yr−1; trend, −14 Tg C yr−1; P < 0.001), more than 30% of the region was a net CO2 source. Tundra regions may have already started to function on average as CO2 sources, demonstrating a shift in carbon dynamics. When fire emissions are factored in, the increasing Arctic–Boreal Zone sink is no longer statistically significant (budget, −319 ± 140 Tg C yr−1; trend, −9 Tg C yr−1), and the permafrost region becomes CO2 neutral (budget, −24 ± 123 Tg C yr−1; trend, −3 Tg C yr−1), underscoring the importance of fire in this region.