Forest clearing contributes to climate change in two main ways: first, vegetation has a large effect on atmospheric CO2 levels (see Emissions section). Second, clearing affects the albedo of a region, or the amount of incoming radiation that is reflected back from a given surface. For example, in the Arctic there are two main types of vegetation cover: forest and tundra. When snow falls on the low-lying tundra it covers the vegetation and reflects sunlight; when snow falls on forest trees it is usually blown away, and rather than being reflected back into space, incoming sunlight is absorbed by the snowless trees.