Industrial animal agriculture is a major driver of biodiversity loss, pollution, soil degradation, wildlife declines, deforestation and greenhouse gas emissions.

Biodiversity loss – There has been a 68% decline in the average size of populations of mammals, birds, fish, reptiles, and amphibians in just over 50 years as rainforests, savannah and pasture are destroyed.
Pollution – Factory farming can create a range of pollution problems, fragmenting and even destroying natural habitats. Waste from factory farms can leak into water courses and, in the worst cases, leaving vast "dead zones", where few species can survive. Some of the nitrogen will also become gaseous, turning into ammonia, which creates problems such as water acidification and ozone layer depletion.
Soil degradation – Industrial agriculture plays a big part in the decline of soils. The United Nations warns that, if we continue as we are, then the world’s soils could cease to be productive in just sixty years’ time.
Wildlife declines – In the last 50 years since the widespread adoption of factory farming, the world has lost more than two-thirds of its wildlife. Wildlife habitats such as forests and savannahs are being destroyed to grow soy and palm oil to feed industrially farmed animals and to provide pasture for cattle - this is driving many species towards extinction. Feed for industrial farms is grown in vast monocultures, usually doused in artificial fertilisers and chemical pesticides. Many trees, bushes and hedges and wildflowers are removed, along with the seeds and insects relied upon by birds, bees, bats, and other wildlife for survival.
Deforestation – As demand for factory farmed meat has grown, great swathes of rainforest in the Amazon and around the world have been devastated; fragile forests, grasslands and savannah cleared for more farmland to grow animal feed like soya.
GHG emissions: livestock rearing is responsible for more greenhouse gas emissions than the exhaust fumes from all the world’s trains, planes and cars put together. Livestock production is already responsible for 14.5% of global anthropogenic greenhouse emissions. Under a business-as-usual model of food production, in which meat and dairy consumption rises in line with a growing global population and rising GDPs, the agriculture sector alone would emit enough greenhouse gasses to take up the entire two degrees Celsius emissions budget by 2050.
Food Waste – The biggest single waste of food is feeding human-edible crops to industrially farmed livestock who convert them inefficiently into meat, milk and eggs, while almost a fifth of the world’s total catch of wild fish is processed into fishmeal and fish oil, largely used to feed farmed fish. In this way, enough food to feed four billion people (half of humanity today) is wasted.

Read more about the impact of factory farming on the planet.