thumb|Cumulative [[Greenhouse gas emissions|CO2 emissions from land-use change (as of 2021). Emissions from land-use change can be positive or negative depending on whether these changes emit (positive, brown on the map) or sequester (negative) carbon (green on the map).]]
Land use is an umbrella term to describe what happens on a parcel of land. It concerns the benefits derived from using the land, and also the land management actions that humans carry out there. Effects of land use choices and changes by humans include, for example, urban sprawl, soil erosion, soil degradation, land degradation and desertification. Land use and land management practices have a major impact on natural resources including water, soil, nutrients, plants and animals.
Land use change is "the change from one land-use category to another".
The study of land change relies on the synthesis of a wide range of data and a diverse range of data collection methods. These include land cover monitoring and assessments, modeling risk and vulnerability, and land change modeling.
Definition and categories
thumb|A graphic description of land use in the [[Australian Capital Territory as of 2017. Colours represent different uses.]]
thumb|The development of global land use over the centuries and millennia: more and more of the world's habitable land is used for agriculture.
The IPCC defines the term land use as the "total of arrangements, activities and inputs applied to a parcel of land". The same report groups land use into the following categories: forest land, cropland (agricultural land), grassland, wetlands, settlements and other lands.
As of the early 1990s, about 13% of the Earth was considered arable land, with 26% in pasture, 32% forests and woodland, and 1.5% urban areas.
For example, the US Department of Agriculture has identified six major types of land use in the United States. Acreage statistics for each type of land use in the contiguous 48 states in 2017 were as follows:
{| class="wikitable"
|+US land use (2017)
Human activity is the most significant cause of land cover change, and humans are also directly impacted by the environmental consequences of these changes. Collective land use and land cover changes have fundamentally altered the functioning of key Earth systems. For instance, human changes to land use and land cover have a profound impact on climate at a local and regional level, which in turn contributes to climate change. Human changes to land surfaces have been documented for centuries as having significant impacts on both earth systems and human well-being. Deforestation is an example of large-scale land use change. The deforestation of temperate regions since 1750 has had a major effect on land cover. The reshaping of landscapes to serve human needs, such as the deforestation for farmland, can have long-term effects on earth systems and exacerbate the causes of climate change.
Land is the foundation of agriculture, supporting over 95% of food production while providing essential ecosystem services that sustain life on Earth. As a finite resource, it faces pressures from competing demands including urban expansion, biofuel production, and changing consumption patterns driven by rising incomes and shifting diets. Land is the basis of food security, biodiversity conservation, climate regulation and in 2025 the livelihoods of 892 million agricultural workers worldwide.
The expansion of agriculture has fundamentally transformed land-use patterns across the planet over the centuries. In the twenty-first century, between 2001 and 2023, global agricultural area decreased by 78 million hectares (Mha) (−2%), with cropland area increasing by 78 Mha and permanent meadows and pastures decreasing by 151 Mha. These changes exhibit significant regional variations. Sub-Saharan Africa witnessed cropland expansion of 69 Mha accompanied by 72 Mha of forest loss, while Latin America saw 25 Mha of cropland growth alongside 85 Mha of net forest area loss. Agricultural expansion remains the primary driver of global deforestation, accounting for nearly 90% of forest loss. In this century, another important aspect to consider is that approximately 3.6 Mha of croplands are abandoned annually, with land degradation likely playing a significant role in these losses.
Analytical methods
Land change science relies heavily on the synthesis of a wide range of data and a diverse range of data collection methods, some of which are detailed below. In the course of monitoring and assessing land cover and land use changes, scientists look at several factors, including where land-cover and land-use are changing, the extent and timescale of changes, and how changes vary through time. The purpose of these tools is to communicate the vulnerability of both human communities and natural ecosystems to hazard events or long-term land change. Modeling risk and vulnerability requires analyses of community sensitivity to hazards, an understanding of geographic distributions of people and infrastructure, and accurate calculation of the probability of specific disturbances occurring. LCMs can be used to predict how land use and land cover may change under alternate circumstances, which is useful for risk assessment, in that it allows for the prediction of potential impacts and can be used to inform policy decisions, albeit with some uncertainty. Rather, deforestation is the result of intertwining systemic forces working simultaneously or sequentially to change land cover. For instance, mass deforestation is often viewed as the product of industrial agriculture, yet a considerable portion old-growth forest deforestation is the result of small-scale migrant farming. According to the United Nations, the global urban population has increased rapidly since 1950, from 751 million to 4.2 billion in 2018, and current trends predict this number will continue to grow. Accompanying this population shift are significant changes in economic flow, culture and lifestyle, and spatial population distribution.
Urbanization is important to land use and land cover change for a variety of reasons. In particular, urbanization affects land change elsewhere through the shifting of urban-rural linkages, or the ecological footprint of the transfer of goods and services between urban and rural areas. The high temperatures associated with heat islands can compromise human health, particularly in low-income areas. In 1960, the Aral Sea, located in Central Asia, was the world's fourth largest lake. However, a water diversion project, undertaken by the Soviet Union to irrigate arid plains in what is now Kazakhstan, Uzbekistan, and Turkmenistan, resulted in the Aral Sea losing 85% of its land cover and 90% of its volume. This use of modeling and satellite imagery to track human-caused land cover change is characteristic of the scope of land change science.
Regulation
Commonly, political jurisdictions will undertake land-use planning and regulate the use of land in an attempt to avoid land-use conflicts. Land use plans are implemented through land division and use ordinances and regulations, such as zoning regulations.
The urban growth boundary is one form of land-use regulation. For example, Portland, Oregon is required to have an urban growth boundary which contains at least of vacant land. Additionally, Oregon restricts the development of farmland. The regulations are controversial, but an economic analysis concluded that farmland appreciated similarly to the other land.
United States
thumb|upright=1.25|[[Habitat fragmentation caused by numerous roads near the Indiana Dunes National Lakeshore]]
In colonial America, few regulations were originally put into place regarding the usage of land. As society shifted from rural to urban, public land regulation became important, especially to city governments trying to control industry, commerce, and housing within their boundaries. The first zoning ordinance was passed in New York City in 1916, and, by the 1930s, most states had adopted zoning laws. In the 1970s, concerns about the environment and historic preservation led to further regulation.
Today, federal, state, and local governments regulate growth and development through statutory law. The majority of controls on land, however, stem from the actions of private developers and individuals. Judicial decisions and enforcement of private land-use arrangements can reinforce public regulation, and achieve forms and levels of control that regulatory zoning cannot. There is growing concern that land use regulation is a direct cause of housing segregation in the United States today.
Two major federal laws passed in the 1960s limit the use of land significantly. These are the National Historic Preservation Act of 1966 (today embodied in 16 U.S.C. 461 et seq.) and the National Environmental Policy Act of 1969 (42 U.S.C. 4321 et seq.).