ENVIRONMENTAL COSTS OF
CONVENTIONAL INTENSIFICATION AND
EXPANSION OF FOOD PRODUCTION
EXPANSION OF CROP- AND RANGELANDS
Modern agricultural methods and technologies brought spec- ible and only about 7,000 are used in agriculture. However,
tacular increases in food production (Tilman et al., 2002), but globalization and agricultural intensification have diminished
not without high environmental costs. Efforts to boost food the varieties traditionally used, with only 30% of the available
production, for example, through direct expansion of cropland crop varieties dominating global agriculture. These, together
and pastures, will negatively affect the capacity of ecosystems to with only 14 animals species, provide an estimated 90% of the
support food production and to provide other essential services. world’s consumed calories (FAO,1998).
Food production will undoubtedly be affected by external fac-
tors such as climate change, but the production and distribu- Habitat modification through agriculture and a variety of other
tion of food is itself is also a major cause of climate change. causes is, in general, the most important factor in increasing
species’ risk of extinction. Most of this habitat loss arises from
Despite its crucial role in feeding the world population, ag- encroaching farmland and habitat conversion for food and bio-
riculture remains the largest driver of genetic erosion, spe- fuel production (Figures 25, 26 and 27). Clearance for cropland
cies loss and conversion of natural habitats (MA, 2005). The or permanent pasture has reduced the extent of natural habi-
conversion of natural habitats to cropland and other uses tats on arable land by more than 50% (Green et al., 2005), with
typically entails the replacement of systems rich in biodiver- much of the rest altered by temporary grazing (Groombridge
sity with monocultures or systems poor in biodiversity. Large- and Jenkins, 2002). Habitat modification already affects more
scale agriculture brings ecosystem simplification and loss of than 80% of the globally threatened mammals, birds and plants
(bio)diversity, thus reducing the potential to provide ecosys- (Groombridge and Jenkins, 2002), with serious implications
tem services other than food production. Of some 270,000 for ecosystem services and human wellbeing. Indeed, the most
known species of higher plants, about 10,000 –15,000 are ed- significant threat by far to the world’s 5,500 mammal species
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