Tropical nighttime warming as a dominant driver of variability in the terrestrial carbon sink
Tropical nighttime warming as a dominant driver of variability in the terrestrial carbon sink
复制标题
DOI：
10.1073/pnas.1521479112
复制
发表时间：
2015-12-22
影响因子：
11.1
通讯作者：
Pacala, Stephen W.
中科院分区：
文献类型：
--
作者：
Anderegg, William R. L.;Ballantyne, Ashley P.;Pacala, Stephen W.
陆地生物圈目前是一个强大的碳(C)汇，但在21世纪，随着气候驱动的碳损失超过二氧化碳驱动的碳收益，陆地生物圈可能转变为碳源，从而加速全球变暖。虽然人们早就认识到热带气候在调节年际气候变率方面起着关键作用，但温度和降水变化与陆地过程之间的因果关系仍然不确定。本文结合大气质量平衡、遥感模拟的植被碳吸收数据集和气候数据集来表征陆地碳汇的时间变异，并确定这种变异的主要气候驱动因素。我们发现，全球陆地碳汇的年际变率在过去50年中增长了50-100%。我们进一步发现，陆地碳汇的年际变率与热带夜间变暖的关系最为密切，可能是通过呼吸作用。呼吸作用对夜间气温的明显敏感性，预计夜间气温的上升速度将快于全球平均气温，这表明储存在热带森林中的碳可能容易受到未来变暖的影响。
The terrestrial biosphere is currently a strong carbon (C) sink but may switch to a source in the 21st century as climate-driven losses exceed CO2-driven C gains, thereby accelerating global warming. Although it has long been recognized that tropical climate plays a critical role in regulating interannual climate variability, the causal link between changes in temperature and precipitation and terrestrial processes remains uncertain. Here, we combine atmospheric mass balance, remote sensing-modeled datasets of vegetation C uptake, and climate datasets to characterize the temporal variability of the terrestrial C sink and determine the dominant climate drivers of this variability. We show that the interannual variability of global land C sink has grown by 50-100% over the past 50 y. We further find that interannual land C sink variability is most strongly linked to tropical nighttime warming, likely through respiration. This apparent sensitivity of respiration to nighttime temperatures, which are projected to increase faster than global average temperatures, suggests that C stored in tropical forests may be vulnerable to future warming.