Environmental scientists study how air, water, land, living things, and human activities interact across Earth.
Environmental science combines biology, chemistry, Earth science, physics, and social science to understand environmental change. Scientists collect evidence in forests, rivers, cities, oceans, laboratories, and from satellites. Their goal is to explain how natural systems work, identify problems, test possible solutions, and help communities make informed decisions.
Food webs, habitats, nutrient cycles, and species interactions connect living things with their surroundings.
Learn MoreWater, soil, forests, minerals, and energy sources support life and human societies.
Learn MoreScientists track contaminants in air, water, and soil and study how they move through environments.
Learn MoreLong-term measurements reveal how temperature, rainfall, oceans, ice, and ecosystems change over time.
Learn MoreConservation uses evidence to protect habitats, species, clean water, healthy soils, and other natural systems.
Learn MoreMonitoring, restoration, cleaner technology, and careful planning can reduce environmental harm.
Learn MoreAn ecosystem includes living organisms and the nonliving environment around them. Plants capture energy from sunlight, animals obtain energy by eating plants or other animals, and decomposers break down dead material so nutrients can be reused. Water, temperature, soil, sunlight, and available nutrients all influence which species can live in a place. Environmental scientists study these relationships because a change in one part of an ecosystem can affect many others.
Natural resources are materials and energy sources people obtain from the environment. Some, such as sunlight and wind, are continually renewed, while others, including many minerals and fossil fuels, form so slowly that they are considered nonrenewable on human timescales. Fresh water, fertile soil, forests, and fisheries can also be depleted if they are used faster than they recover. Environmental science helps measure supply, demand, renewal rates, and the consequences of different ways of using resources.
Pollution occurs when substances or forms of energy enter an environment at levels that cause harm. Air pollutants may come from vehicles, fires, industry, or natural events, while water pollution can include excess nutrients, pathogens, plastics, oil, or toxic chemicals. Scientists sample air, water, sediment, and living organisms to identify sources and concentrations. They also study how pollutants travel, break down, accumulate, or become more concentrated through food webs.
Climate describes long-term patterns in temperature, rainfall, winds, and other conditions, rather than day-to-day weather. Scientists use thermometers, ocean instruments, satellites, ice cores, tree rings, and many other records to study past and present climate. Increasing greenhouse gas concentrations are changing Earth's energy balance, which affects temperatures, sea level, precipitation patterns, and ecosystems. Environmental science examines both the physical changes and how plants, animals, and human communities respond.
Conservation focuses on maintaining healthy ecosystems and preventing unnecessary loss of species and habitats. Scientists may map wildlife populations, measure water quality, track invasive species, study migration routes, or compare protected and unprotected areas. Conservation decisions often involve tradeoffs because people also need land, food, energy, transportation, and housing. Reliable data helps communities compare choices and understand which actions are most likely to protect important environmental functions.
Environmental problems rarely have one simple solution. Scientists test approaches such as restoring wetlands, reducing waste, improving energy efficiency, protecting watersheds, redesigning cities, and using cleaner technologies. Monitoring is essential because a solution must be measured after it is put in place to see whether it actually works. Environmental science is therefore not only about identifying problems; it is also about testing practical ways to reduce harm while meeting human needs.