Climate scientists and permafrost specialists have revealed through new climate computer model simulations that global warming will speed up the melting of permafrost. This change could lead to a sudden increase in wildfires across the Subarctic and Arctic regions of northern Canada and Siberia.
A study published in the journal Nature Communications by an international team of climate scientists and permafrost specialists indicates that, based on new climate computer model simulations, global warming will hasten the thawing of permafrost, which in turn could cause a rapid uptick in wildfires in the Subarctic and Arctic areas of northern Canada and Siberia.
Recent observations indicate that warmer and unusually dry conditions have already led to more frequent wildfires in the Arctic. To understand how human-induced warming may influence future wildfire events, it is crucial to factor in accelerated permafrost thawing, as it significantly affects soil water content—a vital element in fire behavior. Previous climate models did not adequately address how global warming, permafrost thawing in northern latitudes, soil moisture, and wildfires interact.
The recent study utilizes permafrost and wildfire data produced by one of the most detailed earth system models, known as the Community Earth System Model. This model is pioneering in its ability to link soil moisture, permafrost, and wildfires in an integrated manner. To effectively differentiate between the impacts of rising greenhouse gas emissions and natural climate variations, the researchers employed a set of 50 simulations spanning from 1850 to 2100 CE (SSP3-7.0 greenhouse gas emissions scenario). These simulations were carried out by researchers from the IBS Center for Climate Physics in Busan, South Korea, and the National Center for Atmospheric Research in Boulder, Colorado, on the IBS supercomputer Aleph.
Through this modeling strategy, the team illustrated that by the mid to late 21st century, extensive thawing of permafrost due to human activity in the Subarctic and Arctic regions is expected. In many regions, excess soil moisture will drain rapidly, leading to a sharp decline in soil moisture, increased surface warming, and drier air. “These conditions will heighten the risk of wildfires,” states Dr. In-Won Kim, the study’s lead author and a postdoctoral researcher at the IBS Center for Climate Physics in Busan, South Korea. “In the latter half of this century, our model predicts a quick transition from minimal fire activity to highly intense fires within just a few years,” she elaborates.
Moreover, these trends are likely to be exacerbated by an anticipated increase in plant biomass in high-latitude regions, resulting from rising levels of atmospheric CO2. This phenomenon, known as the CO2 fertilization effect, supplies additional fuel for potential fires.
“To improve simulations regarding the future decline of the intricate permafrost landscapes, we must enhance our understanding of small-scale hydrological processes in earth system models by utilizing more extensive observational data sets,” suggests Associate Prof. Hanna Lee, a co-author of the study from the Norwegian University of Science and Technology in Trondheim, Norway.
“Wildfires emit carbon dioxide, along with black and organic carbon into the atmosphere, which can have significant climatic effects and influence the thawing of permafrost in the Arctic. However, the interactions between fire emissions and atmospheric processes have not yet been sufficiently incorporated into earth system models. Addressing this issue will be critical for advancing our understanding,” says Prof. Axel Timmermann, co-author of the study and director of the ICCP as well as a Distinguished Professor at Pusan National University.
