Anthropogenic warming is expected to accelerate global soil organic carbon (SOC) losses via microbial decomposition, yet, there is still no consensus on the loss magnitude. In this Perspective, we argue that, despite the mechanistic uncertainty underlying these losses, there is confidence that a strong, positive land carbon–climate feedback can be expected. Two major lines of evidence support net global SOC losses with warming via increases in soil microbial metabolic activity: the increase in soil respiration with temperature and the accumulation of SOC in low mean annual temperature regions. Warming-induced SOC losses are likely to be of a magnitude relevant for emission negotiations and necessitate more aggressive emission reduction targets to limit climate change to 1.5 °C by 2100. We suggest that microbial community–temperature interactions, and how they are influenced by substrate availability, are promising research areas to improve the accuracy and precision of the magnitude estimates of projected SOC losses.

预计人为变暖将通过微生物分解加速全球土壤有机碳 (SOC) 损失，但对损失程度仍没有达成共识。在这个观点中，我们认为，尽管这些损失背后存在机制上的不确定性，但有信心可以预期强烈、积极的陆地碳气候反馈。两个主要证据支持通过土壤微生物代谢活动增加导致全球 SOC 净损失：土壤呼吸随温度增加和 SOC 在低年平均温度区域的积累。变暖引起的 SOC 损失可能与排放谈判相关，需要更积极的减排目标，以将气候变化限制在 2100 年的 1.5 °C。我们建议微生物群落-温度相互作用，