Arctic ‘albedo’ reflective cooling

and its +ve feedbacks

One feedback, the ‘albedo flip’ property of ice/water, provides a powerful trigger mechanism. A climate forcing that ‘flips’ the albedo of a sufficient portion of an ice sheet can spark a cataclysm. Climate change and trace gases JAMES HANSEN et al 2007

Snow

Sea ice

Exposed land

Open ocean

2012 record Arctic summer sea ice loss

Three large sources of Arctic albedo cooling

> Far North snow cover > Summer sea ice extent > Greenland ice sheet surface

Arctic summer albedo is the ‘air conditioner ‘ for the entire Northern hemisphere

Loss of Arctic cooling is the first of a series of strong Arctic +ve (bad) feedbacks

us

Arctic climate positive (bad) feedbacks are caused by the very rapid warming of the Arctic region due to global warming, which is now 3 to 4 times the rate of global warming. The effect of the multiple Arctic feedbacks is to amplify the Arctic warming, Northern hemisphere warming and to some extent global warming. The Arctic +ve feedbacks 1. Snow albedo spring summer cooling loss of (about the same warming as sea ice loss). 2. Sea ice albedo summer cooling loss of the sea ice Loss of, would be about one third of the warming by CO2. The extent is about the same as the permafrost. 3. Peat rich wetlands warming increases emissions of methane (70 times CO2 warming over 20 years). 4. Permafrost methane emissions from thawing (permafrost has double all atmospheric carbon). 5. Permafrost nitrous oxide emissions from thawing cryoturbation. 6. Methane hydrate - Emissions of methane from destabilized ‘melting’ sea floor frozen solid Arctic methane gas hydrates (1 to 2 times atmospheric carbon).

All Arctic sources of feedback methane emissions are releasing more methane, in relatively small amounts today- but this will be greatly increased with continued rapid loss of Arctic snow and ice albedo cooling.

Loss of Arctic cooling is the first of a series of strong Arctic +ve (bad) feedbacks

The loss of Arctic snow and summer sea ice albedo, by increasing Arctic warming, will increase the rate of Arctic methane (and CO2) feedback emissions, and the rate of Greenland ice sheet melting

Warming peat rich wetlands

Thawing permafrost Melting sea floor methane hydrate

Thin ice less albedo

Dark open water

Snow and ice reflect almost all incoming solar energy back out to space . Snow is the very best

reflector

there is.

The loss of Arctic albedo is a +ve feedback

Sea ice

Open ocean

2012 record Arctic summer sea ice loss

Arctic summer sea ice albedo cooling

Less sea ice extent More thin ice More dark open water

As snow and ice melt away this cooling effect lessens- resulting in warming This is positive feed back effect of global (Arctic) warming

Feedback

Thin ice less albedo

Thin first year or melting ice has less albedo than thick multi year ice. Therefore thinning of the ice as well as decreasing ice extent reduces albedo.

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Dark open water

Dark open ocean water is the best absorber of heat energy there is. It absorbs almost all the incoming solar energy as heat. This warms the Arctic surface sea water and the air above it.

Feed back

Dark ocean water opens up as sea ice melts away which absorbs Heat.

Feed back

Melting ice requires a tremendous amount of energy to force the physical phase change of solid ice to liquid water. This is using up a lot of the solar energy during the Arctic summer , that will become available to cause more surface warming as more ice is melted.

Latent heat of ice

The layer of intact sea ice insulates the ocean water from warmer air above in the Arctic summer. As sea ice melts this insulation is lost.

Feedback

Insulating layer of sea ice and snow

Thin ice less albedo

Dark open water

Loss of Arctic snow and summer sea ice albedo positive feedbacks