positive feedback loop

When rising temperatures alter the environment in a way that intensifies the rate of overheating, a positive feedback loop is created. For instance, the melting of permafrost in Arctic tundra may trigger a release of methane from frozen hydrates. Methane is a highly potent greenhouse gas and its increased concentration in the atmosphere will likely speed the rate of global heating – so releasing more methane.

– Down to Earth newsletter

^ Positive as in reinforcing. Not positive in general.

Positive feedback is any process where the result magnifies the cause: an example is the screech which comes from a sound system when the signal from the speaker is itself picked up by the mic, which feeds it through to the speaker, forming a continuous loop.

– The Entropy of Capitalism