CO2 forcing induces semi‐direct effects with consequences for climate feedback interpretations
CO2 forcing induces semi‐direct effects with consequences for climate feedback interpretations
复制标题
二氧化碳强迫引起半直接效应，对气候反馈解释产生影响
DOI：
10.1029/2007gl032273
复制
发表时间：
2008
影响因子：
5.2
通讯作者：
P. Forster
中科院分区：
文献类型：
--
作者：
T. Andrews;P. Forster
气候强迫和反馈是使用回归方法从7个2 × CO2的板状海洋GCM诊断的。结果进行了比较，使用传统的方法来获得半直接强迫由于对流层调整，类似于吸收气溶胶的半直接影响。所有模型都显示了云的半直接效应，表明云对CO2的快速响应;云通常会减少，从而加剧变暖。同样，有证据表明水蒸气、直减率、冰和雪的半直接影响。以前对气候反馈的估计不太可能考虑到这些半直接的影响，因此将过程误解为仅依赖于强迫而不是全球表面温度的反馈。我们表明，实际的云反馈比以前的方法所建议的要小，并且云响应的很大一部分以及以前的云反馈模型估计值之间的巨大差异是由于半直接强迫。
Climate forcing and feedbacks are diagnosed from seven slab‐ocean GCMs for 2 × CO2 using a regression method. Results are compared to those using conventional methodologies to derive a semi‐direct forcing due to tropospheric adjustment, analogous to the semi‐direct effect of absorbing aerosols. All models show a cloud semi‐direct effect, indicating a rapid cloud response to CO2; cloud typically decreases, enhancing the warming. Similarly there is evidence of semi‐direct effects from water‐vapour, lapse‐rate, ice and snow. Previous estimates of climate feedbacks are unlikely to have taken these semi‐direct effects into account and so misinterpret processes as feedbacks that depend only on the forcing, but not the global surface temperature. We show that the actual cloud feedback is smaller than what previous methods suggest and that a significant part of the cloud response and the large spread between previous model estimates of cloud feedback is due to the semi‐direct forcing.