In the Amazon rainforest, a howler monkey swings from tree to tree as a family of green winged macaws fly over the forest canopy below. These animals will soon have their home deliberately destroyed to make way for cattle ranching and soy farming. Trees will be felled and the forest set alight to transform this species-rich ecosystem into monotonous, managed agricultural land.
“Land use, land use change, and forestry” (LULUCF), also known as “forestry and other land use” (FOLU), is a collective term used in international climate policy. In national greenhouse gas (GHG) inventories, LULUCF is a sector that includes the emissions released and captured by managed areas of land. “Land use,” “land use change,” and “forestry” also each have their own meanings.
“Land use” describes the human purposes for which an area of land is managed, such as for agricultural, industrial, recreational, or residential activities. Land use is separate from “land cover,” which describes the physical type of land rather than what it is used for. When reporting on national GHG emissions, countries sort land use into the following categories: forest land, cropland, grassland, wetlands, settlements, and other lands.
Land accounts for 29 percent of Earth’s surface area (71 percent is water), and a total of 29 percent of Earth’s land is either covered by permanent snow and ice or is barren. The remaining 71 percent of the world’s land is the surface area that can physically be used by humans.
Agriculture is the world’s single biggest use of land, stretching across 50 percent of the planet’s habitable surface. Meat and dairy products are, by nature, much more land-intensive to produce than plant-based foods. Thanks to the relative inefficiency of farming animals for food, animal agriculture takes up 83 percent of global farmland but only produces 18 percent of calories and 37 percent of protein.
Land use change refers to the conversion of an area of land's use by humans from one state to another. Land may be converted from grassland to cropland, or from wilderness to land to graze cattle.
Forestry is the use and management of trees and other forest resources for human benefit. Worldwide, around 1.15 billion hectares of forest are used by humans, mainly for the production of wood and other forest commodities. A further 749 million hectares are managed for multiple other purposes. In the United States, livestock grazing is permitted on over 102 million acres of 193 million acres within the National Forest System lands spread across 29 states.
An estimated 80 percent of land use change worldwide is caused by agriculture. While population increase is the main driver of agricultural land use change, diet also plays a key role. As people become wealthier, they tend to eat more meat and dairy. Researchers estimate that animal agriculture was responsible for 65 percent of global land use change between 1961 and 2011.
The landscape of the world has changed significantly since humans began converting wild spaces into farmland and urban areas. According to a U.N. report, human activity has, over time, “severely altered” three-quarters of Earth’s land surface. In a 2021 study, researchers estimated that between 1960 and 2019, 32 percent of the Earth’s land area was impacted by land use change.
A thousand years ago, the world’s farmland covered a total of just 4 million square kilometers. Fast forward to today, and the amount of land used for agriculture has increased to 51 million square kilometers. Built-up, or urban area has also increased, but takes up much less space than agriculture.
Researchers estimate that 8.6 percent of land area in the contiguous U.S. was altered at least once between 1973 and 2000. Higher crop yields have allowed the overall size of land used for agriculture across the country to decrease from 63 percent in 1949 to 52 percent in 2012. However, farmland in many areas has expanded, often at the expense of important ecosystems such as grasslands and wetlands.
The higher the number of people on the planet, the more demand there is for food. Human population increase either requires more land to be converted to cropland and pasture or requires existing agricultural land to be farmed more intensively.
Some researchers believe that we have already reached “peak farmland” because higher crop yields will allow farmers to produce more than enough food for a growing population with the land that is already used for agriculture. However, a report by the World Resources Institute estimates that even if agricultural yields keep rising, the world will need 593 million hectares more farmland in 2050 than it did in 2010.
When it comes to the amount of land needed for agriculture, it not only matters how many mouths there are to feed but also what those people eat. If, hypothetically, everyone in the world followed the diet of the average person in the U.S., there would not be enough space to produce all the food required even if every single inch of Earth’s habitable land was turned over to farming. If, on the other hand, everyone in the world dropped animal products from their diet, the amount of land needed for agriculture would be reduced by 75 percent.
One example of land use change is deforestation (the clearing of forest areas). According to estimates by the Food and Agriculture Organization of the United Nations, 420 million hectares of global forest cover were destroyed in just three decades between 1990 and 2020. While the rate has slowed down, with forest losses having decreased to 10.2 million hectares per year between 2015 and 2020, deforestation still remains a major environmental concern.
Beef, soy, and palm oil production make agriculture the world’s biggest driver of deforestation. To meet the growing global demand for meat, biodiverse forests that are home to thousands of plant and animal species are being decimated and turned into cattle ranches or intensive soy plantations. Animal agriculture was responsible for around 63 percent of deforestation in the Brazilian Amazon between 2000 and 2013.
Land use change is one of the biggest impacts that humans have had on the global environment. Converting wild spaces to farmland destroys vital ecosystems, pushes wild animals to extinction, and threatens global biodiversity.
However, land use change is not always bad. In many parts of the world, people are working to restore areas of land as the biodiverse ecosystems that they were before human interference. This kind of land use change—known as rewilding—has numerous positive environmental impacts, and in some cases land that has been used for farming animals is being given back to nature.
But while some land is being restored, other areas are still being destroyed. Land use change and land use intensification are responsible for releasing huge amounts of carbon into the atmosphere, contributing to climate change, and harming the environment.
Ecosystems such as peatlands, grasslands, and forests are typically natural carbon “sinks,” meaning that they absorb more carbon than they release. Clearing vegetation, draining wetlands, cutting down trees, and plowing soil so that wild areas can be converted to farmland releases stored carbon into the atmosphere, mainly in the form of carbon dioxide, and reduces the capacity of the land to sequester human-caused carbon emissions.
While land that is managed sustainably can be used to help minimize the impacts of global warming, land use change is currently a major contributor to climate change. Land use changes are a key source of carbon dioxide, nitrous oxide, and methane, accounting for an estimated 23 percent of global greenhouse gas emissions, but can impact the climate in other ways too.
Land use change often causes land cover change, which is in turn closely linked with climate change. Tropical forests, for example, not only store carbon but also supply a range of “ecosystem services” such as helping the soil retain its moisture, keeping the air humid, and reducing the amount of sunlight that gets through. The conversion of tropical forests to agricultural land impacts the climate of a region by disrupting these natural processes. Changes in vegetation cover affect Earth’s surface energy balance which can result in warmer or cooler surface temperatures.
Land use change has an enormous negative impact on the natural environment. The conversion of wildlife habitats to farmland and the increasingly intensive use of existing agricultural land drive are two primary causes of land degradation, an environmental problem that has so far made 23 percent of global land surface area less productive and risks causing further agricultural expansion.
Land use change is also a major driver of biodiversity loss. The ecological importance of temperate grasslands is often overlooked, and these areas are Earth’s most endangered ecosystems. Central North America’s tallgrass prairie, for example, previously stretched across approximately 60 million hectares of land between northern Texas and Manitoba. Most of it has now disappeared, largely because of agricultural expansion, making it difficult for grassland bird species such as Henslow’s Sparrow, Greater Prairie-Chicken, and Eastern Meadowlark to survive. Overall, grassland bird populations in the U.S. fell by more than 40 percent in just over 50 years between 1966 and 2019.
Land use change for agriculture, especially meat and dairy production, is harming the planet (and all who live on it) in numerous ways. Ending factory farming in favor of a more ethical and sustainable plant-based food system will help to stop agricultural expansion from destroying any more of the natural world and will free up land for habitat restoration.