With about 30 percent of the planet’s ice-free surfaces being used for livestock production, this industry is by far the largest use of land resources. The structure and methods of livestock production vary greatly with a location’s geography, economy, culture, and food needs, and these practices can have both positive and negative effects on the environment, public health, and economic growth. Raising livestock is also one of the fastest-growing categories of agriculture, depended on by people around the world for income and nutrition.

During the transition from hunter-gatherer lifestyles to stationary agricultural communities over 10,000 years ago, many species were domesticated and bred. Over time, this led to the livestock animals we are familiar with today such as pigs, cows, and sheep, many of which have become unsuited to live in the wild without food or shelter from humans. The modern livestock industry represents 34 percent of global food protein supply and supports at least 1.3 billion people.

Although some form of livestock production is necessary to provide for the global population, large-scale operations can cause significant harm to the land, water, and atmosphere. Converting land from forest to pastures for livestock is one of the leading reasons for tropical deforestation, and runoff contaminated by manure from livestock production pollutes groundwater, rivers, and lakes. Pesticides, which are used to protect pastures and crops for livestock feed, can contaminate soil and water and be toxic to birds, fish, and helpful insects. Large-scale, unsustainable strategies, called concentrated animal feeding operations or CAFOs, are substantial contributors to dangerous greenhouse gas emissions—livestock emit about 64 percent of total ammonia emissions and between 35 and 40 percent of methane emissions, contributing to acid rain and global climate change.

On the other hand, not all techniques have the same impact, and sustainable livestock production has been an important part of human life for millennia. Methods of livestock production are very different in different parts of the world due to topography, weather, and the needs of the population. In countries like the United States, Brazil, and China, the scale of livestock production is much larger than countries with smaller populations and, therefore, less demand for food products. Lifestyle and culture can also influence the types of animals popular in livestock production, like in Bangladesh, where goats are allowed to graze around properties of rural or poverty-stricken families and can assist with food, clothing, and power. In Nepal, the most widely-practiced religion is Hinduism which views cows as a sacred symbol of life and discourages beef consumption—making other livestock animals (in this case, buffalo) more popular.

This map layer, with data from the Food and Agriculture Organization of the United Nations, shows the most common livestock species by quantity in 2020, including cattle, sheep, goats, horses, pigs, chicken, and duck. With livestock production, specifically CAFOs, contributing such a significant amount to global warming, it is important to be mindful of what you eat and where it comes from. Consider buying your protein from smaller livestock production operations, or including less meat in your diet altogether by joining the Meatless Monday campaign.