Land Use and Impacts on Ecosystems ( WRI Resource Watch)
Since the invention of agriculture 8,000–10,000 years ago, growing crops and raising livestock have been the primary causes of ecosystem loss and degradation. Today agriculture remains the dominant driver of tropical deforestation and associated impacts on biodiversity. Agricultural land makes up more than one-third of the Earth’s land outside of Antarctica, but arable land represents only 10 percent of the total land area. Cropland productivity must therefore increase in order to help close a calorie gap of approximately 70 percent by 2050 without further expansion of cropland into native ecosystems.
Excluding Antarctica, one-quarter of the Earth's landmass is used as pasture. While the world’s drier pasture lands are not suitable for growing crops, beef production remains a leading driver of tropical deforestation as areas are cleared to expand grazing area, and beef demand is expected to nearly double between 2006 and 2050. Sustainably boosting pasture productivity will be important to help meet that demand while reducing pressure on forests.
Agriculture accounts for 70 percent of all freshwater withdrawn from rivers, lakes, and aquifers, and for 80-90 percent of freshwater that human activities consume. Agriculture is also the primary source of nutrient runoff from farm fields, which creates “dead zones” and toxic algal blooms in coastal waters and aquatic ecosystems. Moreover, water stress on cropping, already substantial in some areas, is likely to increase due both to growing water demand and climate change.