Glaciology is the study of ice in the environment.
Important components are seasonal snow , sea ice , glaciers , ice sheets and frozen ground .
The extent of these types of ice reflects the present and past climate. The ice also affects climate. For example, the large areas covered by snow and sea ice reflect solar radiation away from the Earth's surface and thereby influence the heat balance of the earth. Because these ice components are only decimeters to meters thick, they can change on time scales as short as seasons and can influence climate at all time scales. Glaciers and ice sheets are hundreds to more than one thousand meters thick and change significantly only on decadal or much longer time scale.