Climate feedback is a response to a climate process that either intensifies or minimizes the initial effect of a climate forcing (often either warming or cooling). Essentially, these climate feedback effects occur after an initial forcing (warming or cooling) causes a change, and this change in turn influences the severity of the initial change. These responses are separated into two major categories based on whether they make the initial change more or less intense. Positive feedback increases an initial change in the environment - pushing it farther from the balance that the climate has been in, whereas a negative feedback is one that reduces the effect of some initial change in the environment, bringing it back to a more stable state.
Figure 1. The melting of polar ice is an example of a positive feedback.
Figure 2. Excess cloud formation from ocean evaporation is an example of a negative feedback.
Positive climate feedback is any process that creates a bigger change after some initial change, essentially magnifying it. The phrase 'positive' climate feedback has made it sound like these feedback cycles are good, but quite the opposite is true, positive feedback cycles endanger the climate by knocking it further from a stable equilibrium. These include:
Negative climate feedback is a process that is one type of climate feedback wherein some initial change causes some secondary change that in turn decreases the initial change, essentially minimizing the initial change - keeping the climate in a stable state. Processes that have a negative climate feedback keep the Earth's climate stable, which is a good thing. These include:
A wide variety of climate feedbacks can occur as a result of some initial change to the climate, generally through climate forcings. The warming as a result of fossil fuel combustion is one of the primary processes that triggers a feedback. Then, depending on the type of feedback, the initial change in the climate is either enhanced or diminished.
The positive feedback cycles are disconcerting when the climate is concerned. This type of feedback contributes to accelerating climate changes as they increase some already high amount of temperature increase. With positive feedback, some minor change in the state of the climate can result in a large change overall. Thus different types of feedback can cause different changes in the climate, but if it is a positive feedback the initial warming can propagate into a cycle of steadily increasing warming,