Climate change: Forest fire size amplifies postfire land surface warming
Update time:2024-09-27
On September 25, the prestigious international academic journal Nature published an academic paper led by Professor Chao Yue from the College of Soil and Water Conservation Science and Engineering at Northwest A&F University, titled "Forest fire size amplifies postfire land surface warming." This research has made breakthrough contributions in the field of ecological climate effects of forest wildfires, systematically revealing the processes and mechanisms by which extreme forest fires amplify postfire land surface warming, thereby exacerbating global climate warming.
Forest fires have become more frequent and larger, with some areas like the western USA and eastern Spain experiencing fire events that have doubled or tripled in size in recent decades. Larger forest fires typically result in greater loss of vegetation, but the effects of this increase of exposed land on the climate have not yet been established.
Chao Yue and colleagues analysed satellite data of wildfire events from 2003–2016 in northern temperate and boreal forests (40° N–70° N). They found a widespread warming effect one year after fire events—which is consistent with previous research—but, through a mathematical model, calculated that fire size amplified surface warming in North America and eastern boreal Asia. The analysis revealed that evapotranspiration and surface reflectivity decreased one year following a fire event—with greater decreases following larger fires—meaning that the surface was warming by releasing less water and absorbing more incoming radiation than previous years (Fig.1). Meanwhile, the amplified surface warming effect was not observed in western, central, and southeastern Siberia, and eastern Europe, which contain mixed forests and forests primarily composed of deciduous broadleaf trees.
The authors note that these trees may help moderate fire vulnerability and that future fire mitigation strategies could involve increasing the number of broadleaf trees in forests to weaken post-fire surface warming. However, further research is needed to assess how broadleaf trees may help suppress surface warming in Eurasian forests.
This research not only provides a new perspective for understanding the ecological climate effects of forest wildfires but also offers important references for future forest management and climate change mitigation strategies.
Northwest A&F University is the first and corresponding institution for the paper. Jie Zhao, a doctoral student from the 2022 cohort, is the first author, while Professor Chao Yue is a co-first author and the sole corresponding author. Collaborators include master's student Jiaming Wang, doctoral student Hongfei Zhao, and undergraduate Guangyao Li from Northwest A&F University, Professor Sebastiaan Luyssaert from Vrije Universiteit Amsterdam, Researcher Stijn Hantson from Universidad del Rosario in Colombia, Researcher Xianli Wang from Natural Resources Canada, Professor Binbin He from the University of Electronic Science and Technology, and Professor Liang Wang from Linyi University. This research was supported by the National Key Research and Development Program of China, the National Science Foundation of China, the Second Tibetan Plateau Scientific Expedition and Research Program and the Strategic Priority Research Program of the Chinese Academy of Sciences.
Fig. 1 | Implications of increasing fire size on future climate and fire activity.
© Institute of Soil and Water Conservation
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Climate change: Forest fire size amplifies postfire land surface warming
On September 25, the prestigious international academic journal Nature published an academic paper led by Professor Chao Yue from the College of Soil and Water Conservation Science and Engineering at Northwest A&F University, titled "Forest fire size amplifies postfire land surface warming." This research has made breakthrough contributions in the field of ecological climate effects of forest wildfires, systematically revealing the processes and mechanisms by which extreme forest fires amplify postfire land surface warming, thereby exacerbating global climate warming.
Forest fires have become more frequent and larger, with some areas like the western USA and eastern Spain experiencing fire events that have doubled or tripled in size in recent decades. Larger forest fires typically result in greater loss of vegetation, but the effects of this increase of exposed land on the climate have not yet been established.
Chao Yue and colleagues analysed satellite data of wildfire events from 2003–2016 in northern temperate and boreal forests (40° N–70° N). They found a widespread warming effect one year after fire events—which is consistent with previous research—but, through a mathematical model, calculated that fire size amplified surface warming in North America and eastern boreal Asia. The analysis revealed that evapotranspiration and surface reflectivity decreased one year following a fire event—with greater decreases following larger fires—meaning that the surface was warming by releasing less water and absorbing more incoming radiation than previous years (Fig.1). Meanwhile, the amplified surface warming effect was not observed in western, central, and southeastern Siberia, and eastern Europe, which contain mixed forests and forests primarily composed of deciduous broadleaf trees.
The authors note that these trees may help moderate fire vulnerability and that future fire mitigation strategies could involve increasing the number of broadleaf trees in forests to weaken post-fire surface warming. However, further research is needed to assess how broadleaf trees may help suppress surface warming in Eurasian forests.
This research not only provides a new perspective for understanding the ecological climate effects of forest wildfires but also offers important references for future forest management and climate change mitigation strategies.
Northwest A&F University is the first and corresponding institution for the paper. Jie Zhao, a doctoral student from the 2022 cohort, is the first author, while Professor Chao Yue is a co-first author and the sole corresponding author. Collaborators include master's student Jiaming Wang, doctoral student Hongfei Zhao, and undergraduate Guangyao Li from Northwest A&F University, Professor Sebastiaan Luyssaert from Vrije Universiteit Amsterdam, Researcher Stijn Hantson from Universidad del Rosario in Colombia, Researcher Xianli Wang from Natural Resources Canada, Professor Binbin He from the University of Electronic Science and Technology, and Professor Liang Wang from Linyi University. This research was supported by the National Key Research and Development Program of China, the National Science Foundation of China, the Second Tibetan Plateau Scientific Expedition and Research Program and the Strategic Priority Research Program of the Chinese Academy of Sciences.
Fig. 1 | Implications of increasing fire size on future climate and fire activity.