A simple scheme for climate feedback analysis

In this study we present a simple scheme for the diagnosis of the strength of climate feedback. The scheme is based on straightforward calculations using the conventional output of a general circulation model ( GCM), and evaluates the major radiative feedbacks concerning the surface, clear- sky atmosphere, and clouds. We place an emphasis on evaluating shortwave ( SW) feedbacks. Assumptions involved in extracting the SW surface feedback are validated by accurate calculations and considered to be acceptable. The performance of our scheme is demonstrated via a doubled CO2 experiment. Compared to conventional methods, we can evaluate SW feedbacks more accurately while the evaluation of LW feedbacks is essentially similar between the two methods. The ready application of our scheme to the output of various GCMs should be of great use for multi- model ensemble analyses, which contribute to reducing the uncertainty in future climate projections.