Monday, August 28, 2006

Glacier Formation 101

So some guy at a self-described "conservative" website decides that a recent BBC news story about the growth of certain glaciers in the Himalayas is "proof" that global warming is a fraud. Let's recall glacier formation 101.

Glaciers are nothing more than snow. If summer temperatures do not melt all the snow that falls in the winter, the snow keeps building up year after year and gradually condenses by weight and pressure into ice. Large bodies of ice are plastic and flow under the force of gravity. We call large bodies of ice flowing under the force of gravity a glacier.

The amount of water vapor the atmosphere can hold is controlled by temperature. As temperature increases, the atmosphere can hold more water vapor. A volume of air at 80 degrees F can hold more water vapor than the same volume at 33 degrees F or -20 degrees F.

If the average winter temperature of a mountain mass increases slightly, snow fall amounts can increase. If this increase in snowfall is not balanced by an increase in summer melting, then glaciers in that mountain mass will tend to grow. If the winter temperature on a mountain mass warms slightly, snow fall can increase significantly. If there is not an equivalent increase in melting, glaciers grow. This is how glaciers form.

Oh. Andean glaciers are melting so fast it is now estimated that many will disappear in 30 years.


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