Recently, a team led by Associate Professor Zeng Zhong from the School of Environmental Science and Engineering at the Southern University of Science and Technology published their latest research in the journal "Innovation." The research team discussed the unprecedented wildfire events in global northern boreal forests triggered by extreme climate in 2023, following the record-breaking wildfires in 2021, and their profound impact on global carbon cycling.
Research Illustration Provided by Southern University of Science and Technology
Previous studies have indicated that the 2021 global boreal forest fires released 1.76 petagrams of carbon dioxide, setting a historical record at that time. In 2023, the carbon emissions from wildfires soared to an unprecedented 3.15 petagrams of carbon dioxide.
The article points out that according to the Global Fire Emissions Database, the carbon emissions from boreal forests in 2023 were more than three standard deviations above the average levels from 2000 to 2020, especially in North America, where the carbon emissions from boreal forests increased by tenfold.
In 2021, the carbon emissions from boreal forests in the Northern Hemisphere were mainly from the northern part of the Eurasian continent. The global North experienced drier climate conditions in 2023 compared to 2021, particularly in North America, where from June to September, the region faced the most severe drought since 2001, which could be a significant factor triggering large-scale extreme wildfires. This phenomenon highlights the significant impact of climate factors on the intensity of such wildfires and the nonlinear relationship between drought climate conditions in North America and the northern Eurasian continent.
Researchers believe that in the long term, forest wildfires should be a process of carbon balance self-regulation in ecosystems. However, under current climate conditions, they have fallen into a vicious cycle, where climate change-induced reduced precipitation and higher temperatures provide favorable conditions for forest fire occurrences, leading to the release of large amounts of black carbon, carbon dioxide, and other greenhouse gases after fires, further exacerbating the global warming process. Additionally, post-fire vegetation recovery, changes in surface albedo, and other factors also affect the energy exchange and carbon cycle between land and the atmosphere.
To comprehensively understand and quantify the impact of wildfire processes on the global carbon cycle and climate system, the article emphasizes the urgent need to combine observational data, satellite remote sensing monitoring, and field measurement data to enhance the understanding of the long-term and short-term impacts of wildfires and improve the simulation of biogeochemical and biogeophysical processes related to wildfires in Earth system models. This will enable the accurate assessment of future climate risks and the development of effective response strategies.
For more information on the related paper: https://doi.org/10.1016/j.xinn.2024.100631
