Abstract
Wildfires over permafrost put perennially frozen carbon at risk.However,wildfire emissions from bio-mass burning over the diverse range of permafrost regions and their share in global wildfire emissions have not been revealed.The results showed a dramatic increase in wildfire carbon emissions from per-mafrost regions over the period 1997-2021.The share of permafrost in global wildfire CO2 emissions increased from 2.42％in 1997 to 20.86％in 2021.Accelerating wildfire emissions from continuous per-mafrost region is the single largest contributor to increased emissions in northern permafrost regions.Fire-induced emissions from 2019 to 2021 alone accounted for approximately 40％of the 25-year total CO2 emissions from continuous permafrost regions.The rise in wildfire emissions from continuous per-mafrost regions is explained by desiccation within a 5-10 cm soil depth,where wildfires combust below-ground fuel.These findings highlight the acceleration of fire-induced carbon emissions from continuous permafrost regions,which disturb the organic carbon stock and accelerate the positive feedback between permafrost degradation and climate warming,thus stimulating permafrost towards a climatic tipping point.
基金项目
National Key R&D Program of China(2022YFF0801904)
NETL
NSTL
万方数据