%26lt;%26lt;The Greenhouse Effect
The greenhouse effect itself occurs when short-wave solar radiation (which is not impeded by the greenhouse gases) heats the surface of the Earth, and the energy is radiated back through the Earth%26#039;s atmosphere as heat, with a longer wavelength. In the wavelengths 5-30µm a lot of this thermal radiation is absorbed by water vapour and carbon dioxide, which in turn radiate it, thus heating the atmosphere. This is what keeps the Earth habitable, - without the greenhouse effect overnight temperatures would plunge and the average surface temperature would be about minus 18oC, about the same as on the moon.
The particular problem arises in the 8-18µm band where water vapour is a weak absorber of radiation and where the Earth%26#039;s thermal radiation is greatest. Part of this %26quot;window%26quot; (12.5-18µm) is largely blocked by carbon dioxide absorption, even at the low levels originally existing in the atmosphere. The remainder of the %26quot;window%26quot; coincides with the absorption proclivities of the other radiative gases: methane, (tropospheric) ozone, CFCs and nitrous oxide. It also appears that increased levels of carbon dioxide will increase the capture of heat in its absorption band to some, perhaps significant, extent.
The result of all this is that less heat is lost to space from the Earth%26#039;s lower atmosphere, and temperatures at the Earth%26#039;s surface are therefore likely to increase.%26gt;%26gt;
There is a problem in deciding what exactly is happening. Some glaciers are having more ice fall off their surfaces, great volumes of ice falling for instance off the Klina Klina Glacier in British Columbia.
It is observed that there is more snow, and more rain falling on the mountains around that glacier.
Does this mean the glacier is melting?
Only partly. There is more total ice in the glacier, but also more water, making it easier for it to slide toward the Pacific inlet. It could go on gaining snow and losing it with no assured way to know that it is diminishing as a whole.
and many ice sheets are melting every single day, by acres.
haven%26#039;t you heard of the polar bears that are dying because of the land mass shrinkage?
