What is meant by a positive feedback loop in global warming?

Answer 1

One form of positive feedback involves water vapour, which is a greenhouse gas. As the temperature rises, the air absorbs more water vapour, which in turn raises the temperature a little further. Fortunately, the feedback is not sufficient to cause a runaway greenhouse effect.

Another feedback loop that might reinforce global warming is the melting of the permafrost in Siberia, Canada and Alaska. The permafrost holds enormous quantities of carbon as frozen vegetation. Should this melt, it will rot anaerobically, producing methane, a greenhouse gas twenty times as potent as carbon dioxide. This can produce a runaway greenhouse effect that would be beyond the power of humans to control.

The albedo effect can provide positive feedback for global warming when sea ice melts. Sea ice reflects more sunlight than does open water, so when it melts the sea tends to warm a little, causing still more sea ice to melt.

Answer 2

Some results of global warming contribute to global warming, is is called a positive feedback loop.

For example, warm water can absorb less carbon dioxide than cold water. If the ocean surface warms up, the ocean becomes less effective as a carbon sink.

Another major problem is that permafrost areas contain a lot of organic material that can start to rot and give off methane once temperatures rise above the freezing point. Methane is a much more effective greenhouse gas than carbon dioxide.

A third problem is snow and ice cover tends to reflect much more sunlight back into space than exposed soil, rock or oceans. Once sea ice melts or land loses snow or glacier cover it heats up more from sunlight, warming up air and accelerating the process in nearby areas.

All of these taken together can cause a run-away effect on global warming if not kept to a minimum level.

A:Positive feedback means that something increases because something has happened from that increase. (A teacher praises a student for good work. So the student works harder. So the teacher praises again. And the student works harder.)

In climate change a warmer atmosphere can hold more moisture. More moisture retains more greenhouse gases. This makes the atmosphere warmer. The warmer atmosphere can hold more water... Etc. This loop is called positive feedback.

Another example is the albedo effect. This means that white icy areas, like sea ice, reflect the sun's heat. As that ice melts, the darker ocean below gets warmer. Because the ice is no longer there, global temperature rises.

Another example is global warming releasing Arctic methane. Scientists have found plumes of methane gas bubbling up from the ocean floor, as methane hydrate (frozen water and methane combined) melts and releases the methane. The methane increases the warming, which means that more methane is released.

Answer 3

Something happens, like Arctic ice melting. The ice used to reflect the radiation, but now that it has gone, global warming gets worse because the dark ocean absorbs, not reflects the radiation.

Answer 4

as climate warms, CO2 increases because plants remove less of it.

Answer 5

high precipitation results in increased plant growth, lowering CO2.