The idea that our climate reacts differently to anthropogenic forcings than to natural instabilities through the phenomenon of “feedbacks”, seems widespread. This paper shows that climate feedbacks are not effects induced by forcings, but in fact “constitute” our climate. Independent from the origin of a disturbance, our climate will always respond according to the Planck feedback parameter λPL. This is not the “basic feedback” of our climate as often quoted, but just the difference between the Surface feedback parameter λS and the sum of Climate feedbacks λFB, according to λPL = –(λS – λFB). The Surface feedback parameter λS is coupled to the Stefan-Boltzmann relation and holds for any planet. The sum of Climate feedbacks λFB on the other hand, is an intrinsic property of our Earth’ specific atmosphere/surface combination. It describes our climate’s reaction to surface temperature changes, governed by water in all its possible forms of aggregation. These findings are supported by analyzing 23 years of incoming- and outgoing radiation data at the Top of the Atmosphere from NASA’s CERES program. This also shows that the observed temperature trend can only be for about 40% attributed to Greenhouse gas forcings.
