A NASA-funded study suggesting winter carbon emissions in the Arctic may add more carbon to the environment each year than Arctic plants produce, marking one stark returns for a region that has been capturing and storing carbon for thousands of years.
The study, published October 21, 2019, in Environmental Change Regulation warns that the loss of winter carbon dioxide from the world's permafrost regions may increase by 41% over the next century if human-caused greenhouse gas emissions continue at their current pace. Carbon released from melt permafrost is not included in most models used to predict future climates.
Permafrost is a carbon-rich ice covering 24% of the Northern Hemisphere area, covering a wide range of territories throughout Alaska, Canada. , Siberia and Greenland. Permafrost holds more carbon than people release by burning fossil fuel, and this permafrost has kept carbon trapped in a freezing embrace for tens of thousands of years. But as global temperatures rise, permafrost shakes and releases greenhouse gases into the sky. "Woods Hole Arctic Program Center Director Sue Natali, lead author of the study, said" Studies focused on individual sites have seen this move, but to date no one has we are clearly calculating the balance of winter carbon throughout the entire Arctic region. "
This study was supported by NASA & # 39; s Arctic-Boreal Vulnerability Experiment (ABoVE) and conducted in coordination with the Permafrost Carbon Network and beyond 50 cooperating institutions In addition to space-based observations of Earth's climate change, NASA supports scientific campaigns that advance our understanding of how our climate is changing. ima and may change in the future. many sites and combined them with remote sensing data and ecosystem models to assess current and future carbon losses during the winter for northern permafrost regions. They estimate a one-year loss of 1.7 billion metric tons of carbon from the permafrost region during the winter from 2003 to 2017 compared to the estimated average of 1 billion metric tons of carbon obtained during the growing season.
To extend model predictions. In the warmer conditions of 2100, the climate was predicted for different scenarios of future fuel emissions to be used to calculate the permafrost effect. If fossil fuel use is moderately reduced over the next century, winter carbon dioxide emissions will increase by 17% compared to current releases. Under a situation where fossil fuel use continued to increase at current rates through the middle of the century, winter emissions of carbon dioxide from permafrost increased by 41%.
"The hotter it gets, the more carbon will be released into the atmosphere from the permafrost region, which will add to the warming," said co-author Brendan Rogers, a climate scientist at Woods Hole Research Center. "About our study, which uses more observations than before, indicates a stronger source of Arctic carbon in winter. We may be witnessing the transition from an annual Arctic carbon sink to a source of carbon, which is not good news. ”
Climate modeling teams around the world are trying to integrate processes and dynamic events that influence permafrost carbon emissions. For example, thermokarst lakes formed by melting ice can accelerate the rate of carbon dioxide emissions by exposing deeper layers of permafrost to warmer temperatures .Also, Arctic and boreal fires, which become more frequent and severe , can remove the insulting top layer of soil, accelerate and deepen the permafrost thaw.
"Those contacts have not been also accounted for most of the models and undoubtedly increased estimates of carbon emissions from the permafrost regions, "Rogers said.
Reference: "Large loss of CO 2 in winter observed throughout permafrost region" by Susan M. Natali, Jennifer D. Watts, Brendan M. Rogers, Stefano Potter, Sarah M. Ludwig, Anne-Katrin Selbmann, Patrick F. Sullivan, Benjamin W. Abbott, Kyle A. Arndt, Leah Birch, Mats P. Björkman, A. Anthony Bloom, Gerardo Celis, Torben R. Christensen, Casper T Christianen, Roisin Commane, Elisabeth J. Cooper, Patrick Crill, Claudia Czimczik, Sergey Davydov, Jinyang Du, Jocelyn E. Egan, Bo Elberling, Eugenie S. Euskirchen, Thomas Friborg, Hélène Genet, Mathias Göckede, Jordan P. Goodrich, Paul G rogan, Manuel Helbig, Elchin E. Jafarov, Julie D. Jastrow, Aram AM Kalhori, Yongwon Kim, John S. Kimball, Lars Kutzbach, Mark J. Lara, Klaus S. Larsen, Bang-Yong Lee, Zhihua Liu, Michael M. Loranty, Magnus Lund, Massimo Lupascu, Nima Madani, Avni Malhotra, Roser Matamala, Jack McFarland, A. David McGuire, Anders Michelsen, Christina Minions, Walter C. Oechel, David Olefeldt, Frans-Jan W. Parmentier, Norbert Pirk, Ben Poulter, William Quinton, Fereidoun Rezanezhad, David Risk, Torsten Sachs, Kevin Schaefer, Niels M. Schmidt, Edward AG Schuur, Philipp R. Semenchuk, Gaius Shaver, Oliver Sonnentag, Gregory Starr, Claire C. Treat, Mark P. Waldrop, Yihui Wang, Jeffrey Welker, Christian Wille, Xiaofeng Xu, Zhen Zhang, Qianlai Zhuang and Donatella Zona, 21 October 2019, Nature of Climate Change .
DOI: 10.1038 / s41558-019-0592-8