Energy budget constraints on climate sensitivity in light of inconstant climate feedbacks
Energy budget constraints on climate sensitivity in light of inconstant climate feedbacks
复制标题
DOI：
10.1038/nclimate3278
复制
发表时间：
2017-05-01
影响因子：
30.7
通讯作者：
Armour, Kyle C.
中科院分区：
文献类型：
--
作者：
Armour, Kyle C.
全球能源收支约束（1-3）表明，平衡气候敏感性约为2摄氏度，低于古气候重建（4），基于过程的观测分析（5-7）和全球气候模型模拟（8，9）的估计。一个关键的假设是，今天推断的气候敏感性也适用于遥远的未来。然而，全球气候模型有力地表明，反馈随着时间的推移而变化，随着接近平衡，气候敏感性有强烈的趋势增加（9-18）。在这里，我认为气候敏感性的能源预算约束的影响，不稳定的气候反馈。我发现，气候敏感性的长期值平均比全球气候模型中瞬时变暖期间推断的值高出26%，当气候敏感性高时，差异更大。此外，在短暂变暖过程中推断的气候敏感性模型值与能量收支观测结果一致（1-3），表明模型并不过于敏感。使用基于模型的气候反馈在未来将如何变化的估计，结合最近的能源预算限制（1，19），产生了2.9摄氏度（1.7-7.1摄氏度，90%置信度）的平衡气候敏感性的当前最佳估计。这些结果表明，从全球能源预算约束估计的气候敏感性与其他方法得出的值和全球气候模式模拟的一致。
Global energy budget constraints(1-3) suggest an equilibrium climate sensitivity around 2 degrees C, which is lower than estimates from palaeoclimate reconstructions(4), process-based observational analyses(5-7), and global climate model simulations(8,9). A key assumption is that the climate sensitivity inferred today also applies to the distant future. Yet, global climate models robustly show that feedbacks vary over time, with a strong tendency for climate sensitivity to increase as equilibrium is approached(9-18). Here I consider the implications of inconstant climate feedbacks for energy budget constraints on climate sensitivity. I find that the long-term value of climate sensitivity is, on average, 26% above that inferred during transient warming within global climate models, with a larger discrepancy when climate sensitivity is high. Moreover, model values of climate sensitivity inferred during transient warming are found to be consistent with energy budget observations(1-3), indicating that the models are not overly sensitive. Using model-based estimates of how climate feedbacks will change in the future, in conjunction with recent energy budget constraints(1,19), produces a current best estimate of equilibrium climate sensitivity of 2.9 degrees C (1.7-7.1 degrees C, 90% confidence). These findings suggest that climate sensitivity estimated from global energy budget constraints is in agreement with values derived from other methods and simulated by global climate models.