During the 1990s, the portion of the globe covered by forests shrank by an estimated 94,000 square kilometres a year, an area roughly the size of
Portugal. Most of the land that was cleared and burned was converted to growing crops and grazing livestock. In Latin America, in particular, most of the deforested land ended up as pasture used to raise cattle in extensive grazing systems. 

Typically, the deforestation process starts when roads are cut through the forest, opening it up for logging and mining. Once the forest along the road has been cleared, commercial or subsistence farmers move in and start growing crops. But forest soils are too nutrient-poor and fragile to sustain crops for long. After two or three years, the soil is depleted. Crop yields fall. The farmers let the grass grow and move on. And the ranchers move in.  Little investment is needed to start raising cattle on cheap or abandoned land where grass is already growing. And the returns can be high, at least for a while. After just five to 10 years, overgrazing and nutrient loss turn the rainforest land that was once a storehouse of biological diversity into an eroded wasteland.  

Particularly in Central and South America, expansion of pastures for livestock production has been one of the driving forces behind this wholesale destruction.  Deforestation causes incalculable environmental damage, releasing billions of tonnes of carbon dioxide into the atmosphere and driving thousands of species of life to extinction each year.  Effective policies are urgently needed to discourage expansion of livestock production.

Each year, U.S. animal farming kills free-roaming animals by the thousands, (in addition to 10 billion cows, chickens, pigs, and others) to prevent them from “interfering” with agricultural operations. Hundreds of thousands of prairie dogs, coyotes, wolves, mountain lions, bears, bison, and other wild animals are shot, maimed, poisoned, and burned alive by farmers and government agents, and tens of millions of starlings and blackbirds are poisoned each year to keep them from eating animal feed.

Another consequence of this ongoing expansion is global malnutrition. Granted hunger is a complex problem, but huge amounts of waste occur because of animal agriculture’s role in the depletion of cultivable land, topsoil, water, energy, and minerals, and the extremely inefficient process of converting plants-based foods into animal-based foods.

A meat-heavy diet requires 10-20 times as much land as a plant-based diet. Nearly half of the world’s grains and soybeans are fed to animals, resulting in a huge waste of food calories. The extent of waste is such that even a 10% drop in US meat consumption would make sufficient food available to feed the world’s starving millions.

Moreover, animal agriculture has been devastating land that could be used for sustainable farming crops. The process begins with clear-cutting of forests to grow animal feed crops. Without the plant growth to hold it in place, topsoil, laden with minerals, fertilizer, and organic debris, is carried by the runoff of rain and melting snow into nearby streams. The insatiable demand for animal feed crops leads to the use of sloping land with greater runoff and arid land requiring irrigation. Irrigation accounts for more than 80% of all water available for human use, leading to widespread water shortages.