c. Feedback mechanisms
A feedback occurs when the output of a system is routed back as input, forming a loop or circuit of cause-and-effect. The Earth's systems interact in this way.
The concept of feedback loops is particularly important in order to understand the process of climate change. Feedback processes often amplify or diminish the effect of each climate forcing and help us determine climate sensitivity (the equilibrium temperature change in response to changes of radiative forcing). Positive feedback amplifies the change, while negative feedback reduces it.