Fundamentals of Land Use

Land Use and Land-Use Change Introduction to Land Use Land use is fundamentally about how humans interact with Earth's surface. Specifically, land use describes what happens on a parcel of land—the benefits that humans derive from it and the management actions performed by humans. This might include growing crops, raising livestock, building cities, protecting forests, or leaving land relatively untouched. Understanding land use is critical to environmental science because our use of land profoundly affects climate, biodiversity, water cycles, and countless other Earth systems. The changes we've made to land use over the past 10,000 years represent one of humanity's most significant alterations to the planet. The Main Categories of Land Use Scientists divide Earth's land into several primary categories to help organize and study how we use different regions: Forest land — areas dominated by trees Cropland — agricultural land used for growing plants for food, feed, or fiber Grassland — areas of grass and shrubs, often used for pasture Wetlands — marshy or waterlogged areas Settlements — urban and developed areas Other lands — remaining areas that don't fit neatly into the above categories These categories help scientists track where human activities are concentrated and how land is being used globally. Global Land-Use Distribution In the early 1990s, Earth's land surface was distributed roughly as follows: 13% arable (suitable for farming) land 26% pasture (grassland for livestock) 32% forest and woodland 1.5% urban settlements The remaining portion consists of deserts, tundra, mountains, and other less productive lands. This snapshot reveals an important point: even in the early 1990s, humans had already claimed significant portions of Earth's surface for our use. Notice how this visualization shows that agriculture (cropland and livestock pasture) dominates our use of habitable land, accounting for 50% of all habitable land surface. This will become important when we discuss land-use change. What Is Land-Use Change? Land-use change refers to the transition from one land-use category to another. In other words, it occurs when humans convert land from one purpose to another—such as clearing forest to create cropland, or converting grassland to build a city. Land-use change is not random or accidental; it is driven by deliberate human decisions and economic incentives. Understanding the causes and consequences of land-use change is essential for addressing climate change and environmental degradation. The Drivers of Land-Use Change Human activities are the most significant cause of land-use change globally. While natural processes (like floods or wildfires) can alter land conditions, human decision-making overwhelmingly drives the conversion of land from one use to another. The primary drivers of land-use change include: Agricultural expansion — clearing forests or grasslands to grow crops or raise livestock Urban development — converting rural or natural land into cities and suburbs Infrastructure development — building roads, dams, and industrial facilities Timber harvesting — removing forests for wood and paper products Economic incentives — where converting land is financially profitable for landowners This visualization starkly illustrates the historical extent of forest loss due to land-use change. Notice how forest coverage has declined dramatically, particularly in recent centuries. The conversion of forests to agricultural land has been one of the largest land-use changes in human history. <extrainfo> This image shows clearing of forest for cattle ranching in Brazil, a concrete example of agricultural expansion driving land-use change in the Amazon region. </extrainfo> The Climate Impact of Land-Use Change Land-use change is a significant contributor to climate change through greenhouse gas emissions. Here's why: When forests are cleared, the carbon stored in trees and soil is released into the atmosphere as carbon dioxide. Additionally, converting natural ecosystems to agriculture often releases nitrous oxide and methane—potent greenhouse gases. The management of agricultural lands through fertilizer use and livestock production also generates emissions. Key fact: Land-use change together with fossil-fuel combustion contributes roughly 35% of anthropogenic (human-caused) carbon dioxide emissions. This means that roughly one-third of the climate-warming emissions humans produce come from how we use land, making this a critical area for climate action. This is particularly striking because it shows that climate change is not solely a problem of energy production and transportation—our choices about land use are equally important drivers of global warming. This global map shows annual CO₂ emissions from land-use change, with darker browns indicating higher emissions. Notice that emissions are concentrated in tropical regions, particularly in areas undergoing rapid deforestation. The Current Extent of Land-Use Transformation Humans have been modifying land for agriculture and settlement for more than 10,000 years. During this time, our impact has progressively grown until today we have fundamentally altered Earth's surface. Current reality: Approximately 50% of Earth's non-ice land surface has been transformed by human activities. Of this transformed land, roughly 40% is used for agriculture (either cropland or pasture). This means that about 20% of Earth's total non-ice land surface is dedicated to food production. Put another way: Humans have left our mark on half the planet, and we use roughly one-fifth of Earth's land simply to feed ourselves. This represents an enormous transformation of Earth's ecosystems. This diagram provides crucial context: of the 71% of habitable land on Earth, 50% is used for agriculture (crop and animal production combined), while only 37% remains as forests. This illustrates how agriculture has become the dominant land use globally. Addressing Land-Use Change: Mitigation Options The good news is that we have multiple strategies to reduce pressure on land and slow further transformation. Rather than continuing to expand agricultural land, we can reduce demand for conversion through: Increasing food productivity — Using better farming techniques, improved crop varieties, and technology to produce more food on the same amount of land. This is called "intensification" and can reduce the need to clear new land. Adopting dietary changes — Reducing consumption of meat and animal products, which require significantly more land than plant-based foods. This is perhaps the most powerful individual action available. Reducing food loss — Approximately one-third of food produced globally is lost or wasted. Reducing this waste directly reduces the need for agricultural expansion. Minimizing waste — Beyond food, reducing overall consumption and waste reduces demand for resource extraction and land conversion. These strategies work together: more efficient food production means we need less land; dietary changes reduce food demand; and reducing waste means less production is needed overall. Each of these approaches represents a point where human choices can reduce the pressure to convert more natural land to human use. <extrainfo> This aerial view shows urban sprawl—the expansion of cities into surrounding land. Urban development is another significant driver of land-use change, though agricultural expansion remains the largest cause globally. </extrainfo> Human decisions about how we use land represent one of the most direct ways we shape our planet's future. Understanding land-use categories, the drivers of change, and the climate consequences gives you the foundation to think critically about this essential topic.