UPDATE: Further Evidence of Low Climate Sensitivity from NASA’s Aqua Satellite Roy Spencer, Ph. D.First of all, my (and even the IPCCs) emphasis on changes in the global radiative budget cannot be overemphasized when we are trying to figure out whether global warming is mostly manmade or natural, and how the climate system responds to forcing.
Changes in the global-average radiative budget are about the only way for the Earth to warm or cool on time scales of years or longer (unless there is some sort of change in geothermal heat flux we wont even go there.)
What we want to know, ultimately, is how much warming will result from the radiative imbalance caused by adding CO2 to the atmosphere. It is natural to try to answer that question by examining how Mother Nature handles things when there are natural, year-to-year warmings and coolings. I believe that the NASA satellite assets we have in orbit right now are going to go a long way toward providing that answer.
The answer depends upon how clouds, evaporation, water vapor, etc., change IN RESPONSE TO a temperature change, thus further altering the radiative balance and final temperature response. This is called feedback, and it is traditionally referenced to a surface temperature change.
who are you going to believe? the data or the models. hahahahaha