The realization that atmospheric radiative feedbacks depend on the underlying patterns of surface warming and global temperature, and thus, change over time has lead to a proliferation of feedback definitions and methods to estimate equilibrium climate sensitivity (ECS). We contrast three flavors of radiative feedbacks – equilibrium, effective, and differential feedback – and discuss their physical interpretations and applications. We show that their values at any given time can differ more than 1  and their implied equilibrium or effective climate sensitivity can differ several degrees. With ten (quasi) equilibrated climate models, we show that 400 years might be enough to estimate the true ECS within a 5% error using a simple regression method utilizing the differential feedback parameter. We argue that a community-wide agreement on the interpretation of the different feedback definitions would advance the quest to narrow the estimate of climate sensitivity.

中文翻译：

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三种辐射反馈及其对估计平衡气候敏感性的影响

认识到大气辐射反馈取决于地表变暖和全球温度的潜在模式，因此，随着时间的推移发生变化，导致了评估平衡气候敏感性 (ECS) 的反馈定义和方法的激增。我们对比了三种类型的辐射反馈——平衡反馈、有效反馈和微分反馈——并讨论了它们的物理解释和应用。我们表明它们在任何给定时间的值可以相差超过 1 它们的隐含平衡或有效气候敏感性可能有几度不同。使用十个（准）平衡气候模型，我们表明 400 年可能足以使用利用差分反馈参数的简单回归方法在 5% 的误差内估计真实的 ECS。我们认为，对不同反馈定义的解释达成全社区一致将推动缩小气候敏感性估计范围的探索。