永久冻土融化正成为全球气候变化中被低估的威胁。永久冻土覆盖北半球约15%的陆地1，其中锁存约1.5万亿吨碳，相当于大气中碳含量的两倍1。随着气候变暖，这些冻结地层不断消融，自1850年以来，北极永久冻土足迹已缩小约12%，且过去50年加速趋势明显1。永久冻土融化会释放甲烷和二氧化碳等温室气体，进一步推高全球气温1。
联合国气候评估中存在重大监测盲点。大多数用于联合国气候报告的模型均未充分考虑永久冻土逐步丧失的影响，且均未包含热浪和火灾后的突然解冻与地表崩塌评估1。野火与极端气候进一步加剧了融化风险，研究表明到本世纪末，火灾加速永久冻土融化可能释放相当于80亿吨二氧化碳的碳1。此外，Yedoma是一种来自更新世晚期的特别深、碳密集的永久冻土类型，因碳含量极高而尤其令人担忧1。由于永久冻土碳循环机制复杂，融化后生态恢复的相关机制仍需进一步深入研究1。
Permafrost covers approximately 15% of the Northern Hemisphere's land surface and plays a critical role in Earth's climate system.1 The Arctic permafrost footprint has shrunk by roughly 12% since 1850, with the rate of decline accelerating over the past 50 years.1 Within this frozen ground lies approximately 1.5 trillion tons of carbon—roughly double the amount currently in the atmosphere—which poses a substantial climate risk if released through thawing.1
The implications of permafrost degradation extend beyond simple melting. Wildfires are accelerating the thaw process, potentially releasing carbon equivalent to 8 billion tons of carbon dioxide by the end of this century.1 A particular concern is Yedoma, a uniquely deep and carbon-dense type of permafrost from the late Pleistocene epoch, which could be especially vulnerable to rapid thaw.1 Most climate models used in United Nations climate reports fail to adequately account for the gradual loss of permafrost and do not incorporate sudden thawing and collapse triggered by heat waves and fires.1
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