Agriculture & Livestock
Modern industrial agriculture is defined as mechanized (tilled and irrigated) monocultures that use large amounts of synthetic petroleum-based fertilizers as well as highly toxic pesticides and herbicides. Notwithstanding land clearing (see deforestation), the direct environmental impacts of industrial agriculture are soil depletion and erosion, loss of healthy soil structure and hydrology, soil salinization/alkalization, inefficient use and pollution (chemical and nutrient) of scarce freshwater resources (surface and ground), and loss of genetic diversity. The so-called “Green Revolution” eliminated hundreds and thousands of traditional crop varieties and replaced them with a handful of modern, higher yielding varieties. Recent advances in genetically modified crops will further increase genetic uniformity and exacerbate the loss of diversity.
In the developing world, the conversion of forest, grasslands, and scrub to livestock pasture results in high rates of soil erosion while subsequent overgrazing and soil compaction tends to further accelerate degradation. In the developed world, most of the cows, chickens and pigs for food production are factory farmed in highly concentrated livestock operations that are far removed from historical ecological cycles. These operations require an inordinate amount of concentrate feed while generating large amounts of toxic waste that pollute surface/ground waters and increase greenhouse gas emissions.