Land surface effects on climate are wide-ranging and vary by region. Deforestation and exploitation ofnatural landscapes play a significant role. Some of these environmental changes are similar to those caused by theeffects of global warming.[1][2][3]
25-50% of the rainfall in the Amazon basin comes from the forest, and if deforestation reaches 30-40% most of the Amazon basin will enter a permanent dry climate.[14] In another article published by Nature, it points out that tropical deforestation can lead to large reductions in observed precipitation.[15]
This concept of land-atmosphere feedback is common amongpermaculturists, such asMasanobu Fukuoka, who, in his book,The One Straw Revolution, said "rain comes from the ground, not the sky."[16][17]
Deforestation, and conversion of grasslands to desert, may also lead to cooling of the regional climate. This is because of thealbedo effect (sunlight reflected by bare ground) during the day, and rapid radiation of heat into space at night, due to the lack ofvegetation andatmospheric moisture.[18]
A rain shadow is a dry area on the leeward side of a mountainous area (away from the wind). The mountains block the passage of rain-producing weather systems and cast a "shadow" of dryness behind them. Wind and moist air are drawn by the prevailing winds towards the top of the mountains, condensing and precipitating before it crosses the top. In an effect opposite that of orographic lift, the air, without much moisture left, advances behind the mountains, creating a drier side called the "rain shadow".[citation needed]
Aföhn orfoehn is a type of dry, warm, down-slope wind that occurs in thelee (downwind side) of a mountain range.[citation needed]
Föhn can be initiated when deep low pressures move into Europe drawing moistMediterranean air over theAlps.
It is arain shadow wind that results from the subsequentadiabatic warming of air that has dropped most of its moisture on windward slopes (seeorographic lift). As a consequence of the different adiabaticlapse rates of moist and dry air, the air on the leeward slopes becomes warmer than equivalent elevations on thewindward slopes. Föhn winds can raisetemperatures by as much as 14 °C (25 °F)[19] in just a matter of minutes. Central Europe enjoys a warmer climate due to the Föhn, as moist winds off the Mediterranean Sea blow over theAlps.[citation needed]
^Peter Greve; Boris Orlowsky; Brigitte Mueller; Justin Sheffield; Markus Reichstein & Sonia I. Seneviratne (2014). "Global assessment of trends in wetting and drying over land".Nature Geoscience.7 (10):716–721.Bibcode:2014NatGe...7..716G.doi:10.1038/ngeo2247.
^1978 [1975 Sep.] –The One-Straw Revolution: An Introduction to Natural Farming, translators Chris Pearce, Tsune Kurosawa and Larry Korn, Rodale Press.
