Albedo

you can’t stop it once it starts. the system’s own response is the accelerator.

melt some ice, expose dark water, absorb more heat, melt more ice

Ice reflects sunlight back to space; open water absorbs it. Melt a little ice and the newly bare water soaks up more heat than the ice did, which warms the planet, which melts more ice — a loop that feeds itself once it has a direction. The push that starts it can be tiny, because the accelerator is the system’s own response, not a bigger shove. That is also why the Arctic is warming nearly four times faster than the global average: it is not being hit harder, it is just further along its own loop.

it runs without you now — the melt keeps feeding itself with your finger off the glass

Concepts: feedback-loops, criticality.

An interactive you play with one thumb, on Wundr.