Positive Reinforcement: The Economist on Feedback Loops


The Economist has run a few loopy articles lately that make one question the value of a subscription. However sometimes they get it right, perhaps when the writer gets out of his/her (you don't know, they never have bylines in the Economist) stuffy office and goes to look at things, like melting ice in Greenland. The writer explains the problem of feedback loops:

"One source of warming causes even more warming by other means. These interactions, called positive feedback loops, worry scientists. For example, a melting ice sheet exposes tundra. Tundra, darker in colour than ice, absorbs more of the sun’s heat. That additional warming leads to more ice melting, which exposes more tundra, and so on. Positive feedback loops thus have a habit of running away with themselves. Instead of a muffling hand, the whisper finds a microphone in an echo chamber."

The columnist concludes with concern about aluminum and oil discoveries in Greenland that excite the locals. "That oil could go into cars, made with Greenlandic aluminium, driving along new Greenlandic roads. The positive feedback loops could make a necklace." ::The Economist