Thepieshowsthattherearefourmaincausesoffarmlandbecomingdegradedintheworldtoday.Globally,65%ofdegradationiscausedbytoomuchanimalgrazingandtreeclearance,constituting35%and30%respectively.Afurther28%ofglobaldegradationisduetoover-cuktivationofcrops.Othercausesaccountforonly7%collectively.
Thesecausesaffecteddifferentregionsdifferentlyinthe1990s,withEurpoehavingasmuchas9.8%ofdegradationduetodeforestation,whiletheimpactofthisonOceaniaandNorthAmericawasminimal,withonly1.7%and0.2%oflandaffectedrespectively.Europe,withthehighestoverallpercentageoflanddegraded(23%),alsosufferedfromover-cultivation(7.7%)andover-grazing(5.5%).Incontrast,Ocesniahad13%ofdegradedfarmlandandthiswasmainlyduetoover-grazing(11.3%).NorthAmericahadalowerproportionofdegradedlandatonly5%,andthemaincausesofthiswereover-cultivation(3.3%)and,toalesserextent,over-grazing(1.5%).
Overall,itisclearthatEuropesufferedmorefromfarmlanddegradationthantheotherregions,andthemaincausesthereweredeforestationandover-cultivation.
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