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Environmental problems
Severe soil erosion in a wheat field near Washington State University, US
(c.2005)Agriculture may often cause environmental problems because it changes
natural environments and produces harmful by-products. Some of the negative
effects are:
Surplus of nitrogen and phosphorus in rivers and lakes
Detrimental effects of herbicides, fungicides, insecticides, and other biocides
Conversion of natural ecosystems of all types into arable land
Consolidation of diverse biomass into a few species
Soil erosion
Depletion of minerals in the soil
Particulate matter, including ammonia and ammonium off-gasing from animal waste
contributing to air pollution
Weed Science - feral plants and animals
Odor from agricultural waste
Soil salination
Agriculture is cited as a significant adverse impact to biodiversity in many
nations' Biodiversity Action Plans, due to reduction of forests and other
habitats when new lands are converted to farming. Some critics also include
agriculture as a cause of current global climate change.
According to the United Nations, the livestock sector (primarily cows, chickens,
and pigs) emerges as one of the top two or three most significant contributors
to our most serious environmental problems, at every scale from local to global.
It is one of the largest sources of greenhouse gases - responsible for 18% of
the world’s greenhouse gas emissions as measured in CO2 equivalents. By
comparison, all transportation emits 13.5% of the CO2. It produces 65% of
human-related nitrous oxide (which has 296 times the global warming potential of
CO2) and 37% of all human-induced methane (which is 23 times as warming as CO2).
It also generates 64% of the ammonia, which contributes to acid rain and
acidification of ecosystems .
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