Max Planck Institute for Meteorology, The Land in the Earth System, Hamburg, Germany.
Center for Earth System Research and Sustainability, University of Hamburg, Hamburg, Germany.
Nat Commun. 2021 May 11;12(1):2688. doi: 10.1038/s41467-021-23010-5.
Minimizing the risks and impacts of climate change requires limiting the global temperature increase to 1.5 °C above preindustrial levels, while the difficulty of reducing carbon emissions at the necessary rate increases the likelihood of temporarily overshooting this climate target. Using simulations with the land surface model JSBACH, we show that it takes high-latitude ecosystems and the state of permafrost-affected soils several centuries to adjust to the atmospheric conditions that arise at the 1.5 °C-target. Here, a temporary warming of the Arctic entails important legacy effects and we show that feedbacks between water-, energy- and carbon cycles allow for multiple steady-states in permafrost regions, which differ with respect to the physical state of the soil, the soil carbon concentrations and the terrestrial carbon uptake and -release. The steady-states depend on the soil organic matter content at the point of climate stabilization, which is significantly affected by an overshoot-induced soil carbon loss.
为了将全球气温上升幅度限制在工业化前水平以上 1.5°C，从而降低气候变化的风险和影响，就必须以必要的速度减少碳排放，而这增加了暂时超过这一气候目标的可能性。利用陆面模式 JSBACH 的模拟结果，我们表明，高纬度生态系统和受永久冻土影响的土壤状态需要几个世纪的时间才能适应 1.5°C 目标所带来的大气条件。在这里，北极的暂时变暖会产生重要的遗留效应，我们表明，水、能量和碳循环之间的反馈作用使得永久冻土地区存在多种稳定状态，这些稳定状态在土壤的物理状态、土壤碳浓度以及陆地碳吸收和释放方面存在差异。这些稳定状态取决于气候稳定时的土壤有机质含量，而这又受到因超过限定值而导致的土壤碳损失的显著影响。
