Positive feedback
means runaway warming «One of the oft - cited predictions of potential warming is that a doubling of atmospheric carbon dioxide levels from pre-industrial levels — from 280 to 560 parts per million — would alone cause average global temperature to increase by about 1.2 °C.
Not exact matches
One of the things that people (particularly from an engineering background) have trouble with is the idea that the feedback from a small amount of
warming can give rise to a much larger amount of
warming, and this seems, from an «enginering perspective» on the
meaning of «feedback», to result in an uncontrolled «
runaway» response.
That doesn't
mean that we shouldn't reduce our dependence on fossil fuels as soon as possible, be it more for geopolitical reasons and pollution reduction than for fear for a
runaway warming...
Actually, by now hopefully it's apparent that I interpreted the question to
mean «
runaway warming» (ala Venus).
A «
runaway greenhouse effect» occurs when something
warms the planet, triggering positive feedbacks which
warm it further; however, even this does not
mean the planet continues
warming infinitely, forever.
The
runaway greenhouse effect has several
meanings ranging from, at the low end, global
warming sufficient to induce out - of - control amplifying feedbacks, such as ice sheet disintegration and melting of methane hydrates, to, at the high end, a Venus - like hothouse with crustal carbon baked into the atmosphere and a surface temperature of several hundred degrees, a climate state from which there is no escape.
That
means there would be
runaway warming there if heat from the deep tropics couldn't be exported to higher latitudes.