Wildfires are important ecosystem processes that have a significant impact on terrestrial vegetation, environment, and climate. This study investigates how future wildfire risk and activities could change under 1.5 °C and 2.0 °C warming scenarios relative to pre-industrial levels using a modified McArthur Forest Fire Danger Index (FFDIn) and the CLM4.5-BGC land surface model. Sixteen Earth System Models (ESMs) from CMIP5 and CMIP6 were employed to supply the variables of climate change under low, middle, and high greenhouse emission scenarios in the 1.5 °C and 2.0 °C scenarios. The ensemble means from the FFDIn and results from the CLM4.5-BGC with multiple forcings show that the dry areas in the southwestern US, Brazilian Highlands, and Arabian islands are projected to face higher wildfire risk with larger burned areas and more carbon emissions under a warmer climate. The Congo Basin and part of the Amazon could have a lower wildfire risk with smaller burned areas and less carbon emissions. The absolute changes in the projected FFDIn are small, although large increases are observed in boreal areas, particularly in the winter and spring. Burned area and carbon emissions are projected to increase in general in the boreal area but decrease in northeastern Asia. Compared to the 1.5 °C scenario, the wildfire risk and burned area levels are projected to increase under the 2.0 °C scenario except in the western Amazon. However, fire carbon emissions are projected to decrease more in tropical areas under the 2.0 °C scenario. The different change directions in eastern North America and eastern China produced by the FFDIn and CLM4.5-BGC suggest the potential effect of non-meteorological elements on fire activities.

中文翻译：

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1.5 °C 和 2.0 °C 全球变暖情景下的野火风险和活动预测

野火是重要的生态系统过程，对陆地植被、环境和气候具有重大影响。本研究使用修改后的麦克阿瑟森林火灾危险指数 (FFDIn) 和 CLM4.5-BGC 陆地表面模型，调查未来野火风险和活动在相对于工业化前水平升温 1.5 °C 和 2.0 °C 的情况下如何变化。来自 CMIP5 和 CMIP6 的 16 个地球系统模型 (ESM) 用于提供 1.5 °C 和 2.0 °C 情景下低、中和高温室排放情景下的气候变化变量。FFDIn 的集合平均值和具有多重强迫的 CLM4.5-BGC 的结果表明，美国西南部、巴西高地、预计阿拉伯岛屿将面临更高的野火风险，因为在气候变暖的情况下，燃烧面积更大，碳排放量更多。刚果盆地和亚马逊部分地区的野火风险可能较低，燃烧面积较小，碳排放量较少。预计 FFDIn 的绝对变化很小，尽管在北方地区观察到大幅增加，尤其是在冬季和春季。预计北方地区的燃烧面积和碳排放量总体上会增加，但在东北亚地区会减少。与 1.5 °C 情景相比，野火风险和火灾面积水平预计在 2.0 °C 情景下会增加，亚马逊西部除外。然而，在 2.0 °C 情景下，预计热带地区的火灾碳排放量将减少更多。