中国科学院大气物理研究所徐希燕教授团队最新的研究，揭示了北极连续永久冻土造成的野火碳排放量加速上升这一新成果。相关论文于2024年5月19日发表于国际顶尖学术期刊《科学通报》杂志上。

据悉，永久冻土上的野火使常年冻结的碳处于危险之中。然而，在不同范围的永久冻土区燃烧生物质产生的野火排放量，及其在全球野火排放中的份额尚未公布。

研究结果显示，1997年至2021年期间，来自永久冻土区的野火碳排放量急剧增加。永久冻土占全球野火二氧化碳排放量的比例从1997年的2.42%增加到2021年的20.86%。该区野火排放的加速是北部永久冻土区排放增加的最大原因。仅2019-2021年的火灾排放就占了连续永久冻土区25年二氧化碳排放总量的40%左右。

连续永久冻土区野火排放量的增加可以解释为土壤深度5-10cm内的干燥，在那里野火消耗地下燃料。研究结果强调了连续永久冻土区火灾引起的碳排放加速扰乱了有机碳储量，加速了永久冻土区退化与气候变暖之间的正反馈，并刺激永久冻土区走向气候临界点。

附：英文原文

Title: Accelerated rise in wildfire carbon emissions from Arctic continuous permafrost

Author: Xiyan Xu a

Issue&Volume: 2024/05/19

Abstract: Wildfires over permafrost put perennially frozen carbon at risk. However, wildfire emissions from biomass 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 permafrost 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 permafrost region is the single largest contributor to increased emissions in northern permafrost regions. Fire-induced emissions from 2019–2021 alone accounted for approximately 40% of the 25-year total CO₂ emissions from continuous permafrost regions. The rise in wildfire emissions from continuous permafrost regions is explained by desiccation within a 5–10 cm soil depth, where wildfires combust belowground 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.

DOI: 10.1016/j.scib.2024.05.022

Source: https://www.sciencedirect.com/science/article/abs/pii/S2095927324003566