Discuss the major environmental impacts of raising livestock for food

Question

What will be an ideal response?

Answer 1

There has been a recent increase in the global demand for meat and dairy products, which has been problematic because livestock need to eat, and the global amount of cropland has remained stable. Feeding increased amounts of crops to livestock (e.g., feeding corn to cows) diverts crops that can be directly used to feed people. It is much less energetically efficient to eat meat than to eat a vegetarian diet, as only about 10% of the energy being fed to livestock ends up passed to the next trophic level (i.e., the humans that eat the livestock). An alternative to feeding crops to livestock is to allow the livestock to roam and graze on rangeland. However, large amounts of water are also needed to raise livestock, and rangeland tends to be quite dry, so the need for water for livestock tends to put a strain on an already scarce resource. Areas where livestock graze are prone to the effects of overgrazing, especially during times of drought. Overgrazing can lead to decreased fertility of the land through soil erosion and desertification. Some areas such as Brazil are being deforested for the purpose of raising livestock. Deforestation causes soil erosion, destroys ecosystems, and contributes to global climate change by putting sequestered carbon dioxide back into the atmosphere and possibly decreasing the area's ability to take up carbon dioxide via photosynthesis. An alternative to allowing livestock to graze on marginal lands is to keep them in a large confined feedlot, but doing so not only stresses the livestock and can lead to disease transmission, but it also creates problems with soil contamination and nutrient pollution in both surface waters and groundwater.