Tipping Elements in the Earth's Climate System (Proceedings of the National Academy of Sciences)

Created by : Francis Goodwin View profile

(Oxford Analytica) -- A recent study, "Tipping Elements in the Earth's Climate System," published in the Proceedings of the National Academy of Sciences, reviews 14 earth systems to assess which ones might have policy-relevant tipping points that would constitute a danger to the global climate.

Tipping points and mechanisms differ across systems but share characteristics. While minor perturbations tend to be unimportant, slight increases can lead to major changes in the system:

--Arctic sea ice. While sea ice is very reflective, the ocean surface is dark and highly absorbent to incoming sunlight. Therefore, melting sea ice can lead to absorption of more energy from the sun, increasing temperatures further. Many models indicate that small arctic ice caps are unstable.

--Greenland Ice Sheet. Unlike sea ice, land-based ice sheets can lead to sea level changes if they melt. Warming can decrease ice extent and lead to feedback similar to sea ice. In some models this leads to complete ice cap melting. The GIS appears to be changing more quickly than models predict, which, if continued, would lead to faster sea level rises.