GLACIER

is a multi-year accumulation of snowfall in excess of snow melt on land, resulting in a mass of ice covering at least a tenth of a square kilometer, that shows some evidence of movement in response to gravity. Glacier ice :is the largest reservoir of fresh water on Earth, and second only to the oceans as the largest reservoir of total water. Glaciers are fo anund on every continent except Australia. Global Change refers to change to the Earth system which :is either a global phenomenon or that occurs regionally, but strongly enough and often enough to be of global significance. The leading current global change :issues include climate change due to an enhanced greenhouse effect, stratospheric ozone depletion, acid precipitation, urban air pollution, and loss of biodiversity.