Livestock and Environment
In recent decades, livestock production has increased rapidly, particularly in the developing world. This expansion of the livestock sector is exerting mounting pressure on the world’s natural resources: grazing land is threatened by degradation; deforestation is occurring to grow animal feed, water resources are becoming scarce; air, soil and water pollution are increasing; and locally adapted animal genetic resources are being lost.
About 20 percent of the world’s pastures and rangelands, with more than 70 percent of the rangelands in dry areas, have been degraded to some extent, mostly through overgrazing, compaction and erosion created by livestock keeping. Dry lands are particularly affected by these trends, as livestock are often the only source of livelihoods for the people living in these areas.
Clearing of land for feed crop production and expansion of pastures for livestock production has been one of the driving forces behind deforestation. Deforestation causes significant environmental damage, releasing enormous amounts of carbon dioxide into the atmosphere and causing the extinction of many animal and plant species each year.
Freshwater is becoming increasingly scarce with the livestock sector accounting for nearly one tenth of global human water use. The livestock sector is probably the largest source of water pollution, contributing to eutrophication, ‘dead’ zones in coastal areas and degradation of coral reefs.
Much of the increased production comes from industrial farms clustered around major urban centres. Such large concentrations of animals close to dense human population often cause considerable pollution problems. The major sources of pollution are animal wastes, antibiotics and hormones, chemicals from tanneries, fertilizers and pesticides used for feedcrops and sediments from eroded pastures.
The livestock sector and the development path it will take thus have deep and wide-ranging environmental impacts that urgently need to be addressed.