Comment: 19:48 - 20:49 (01:01)
Source: Annenberg/CPB Resources - Earth Revealed - 22. Wind, Dust and Deserts
Keywords: vegetation, humans, atmosphere, plant, tree, air, climate, rainfall, semi-arid, desert, desertification, agriculture, grazing
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Our transcription: If great amounts of vegetation are destroyed as land is developed or overgrazed, the bare earth may be exposed, reflecting heat back into the atmosphere.
If there are no trees or plants to store heat and release moisture, the air gets warmer and dryer, and there's less chance of rain.
With no tree or plant cover for anchorage, the topsoil can erode rapidly discouraging new plants from taking root.
If the region lies in a semi-arid climate or near the margin of a desert, this destruction of soil and vegetation may convert it into new desert.
This change may be permanent for all practical purposes, for once desertification starts it takes a costly effort to stop.
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Geology School Keywords
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