63 of the ESS glossary’s terms, each with the part of the syllabus where you first meet it.
A non-living physical or chemical component of an ecosystem that affects living organisms, such as temperature, light, pH, salinity, dissolved oxygen or soil texture.
A situation in which total environmental pressure, such as emissions or resource use, falls while GDP continues to grow.
The removal of water from a river, lake, reservoir or aquifer by humans, for drinking water, irrigation, industry or energy.
The number of individuals of a species in a given area, or a relative measure of how common it is.
The rules under which users of genetic resources obtain the provider country's prior informed consent and agree terms to share the benefits, such as money or research results.
The closeness of a measurement or result to the true value of the quantity being measured.
The transfer of acids and acid-forming gases and particles from the atmosphere to the ground, either dissolved in precipitation (wet deposition) or as gases and particles (dry deposition).
Rain, snow or fog with a pH below that of unpolluted rain (about 5.6), caused by sulfuric and nitric acids formed from sulfur dioxide and nitrogen oxides in the atmosphere.
A heritable characteristic that increases an organism's chance of surviving and reproducing in its environment, produced over generations by natural selection.
The attraction of water molecules to the molecules of other substances, such as the walls of plant xylem or soil particles.
The horizontal transfer of water vapour, or of the droplets and ice crystals in clouds, by the wind from one place to another.
The movement of air into and out of soil pore spaces, which supplies oxygen to roots and soil organisms and removes carbon dioxide.
A suspension of fine solid particles or liquid droplets in the air, such as dust, sea salt, sulfate droplets or soot, which affects climate by scattering or absorbing radiation and by changing clouds.
The worth people place on natural capital for its beauty and the pleasure of seeing or experiencing it, such as scenic mountains, coasts or lakes.
The planting of trees on land that has not been forested for a long time, or never was, creating a new forest that stores carbon.
A pair of back-to-back horizontal bar graphs showing the number or percentage of males and females in each age group of a population, with the youngest at the base.
A population in which the proportion of older people, usually those aged 65 and over, is rising, because of falling fertility and rising life expectancy.
A non-binding United Nations action plan for sustainable development agreed at the 1992 Rio Earth Summit, to be carried out by governments and organisations from the global to the local level.
Water flowing over or through farmland into streams and lakes, carrying fertiliser nutrients, manure, pesticides and soil particles with it.
A chemical product used in agriculture, such as a synthetic fertilizer, pesticide, herbicide or growth regulator.
A land-use system in which trees or shrubs are grown together with crops or livestock on the same land, to gain from their interactions.
A single number on a fixed scale, calculated from measured concentrations of several pollutants, that communicates how polluted the air is and how much risk it poses to health.
The proportion of incoming solar radiation reflected by a surface, from 0 to 1; snow and ice have a high albedo, dark ocean and forest a low one.
A rapid increase in the population of phytoplankton, such as algae or cyanobacteria, in a water body, usually after an increase in a limiting nutrient, that discolours the water.
A species introduced by human activity, deliberately or accidentally, to an area outside its natural range; also called a non-native or introduced species.
The formation of new species from populations separated geographically, for example by a river, sea or mountain range.
The statement, accepted when a statistical test rejects the null hypothesis, that there is a real difference, correlation or association between the variables studied.
Two or more different conditions in which the same system can persist under similar circumstances, each maintained by its own feedback loops.
The height of a place above sea level; temperature usually falls as altitude increases, producing zones of vegetation on mountains.
The release of aluminium ions from soil minerals into soil water and streams when the soil becomes acidic, where they are toxic to fish, other aquatic organisms and plant roots.
A compound of nitrogen and hydrogen (NH₃) made by nitrogen fixation and by the Haber process; the starting material for most synthetic nitrogen fertilisers.
The release of ammonium from the nitrogen-containing organic compounds in dead organisms and wastes, carried out by decomposers.
The positively charged ion NH₄⁺, formed when ammonia dissolves in soil water; a form of inorganic nitrogen released by decomposition and used by nitrifying bacteria.
Conditions in which oxygen is absent or very scarce, such as waterlogged soils, swamp sediments and animal guts, where only organisms that do not need oxygen can respire.
The breakdown of organic waste by microorganisms in a sealed tank without oxygen, producing biogas (mainly methane) used as fuel and digestate used as fertiliser.
A soil formed on volcanic ash, with a low bulk density, that is often very fertile and supports intensive farming, as in Java and Japan.
The view that animals, or at least sentient animals, have moral rights, such as a right not to be killed or made to suffer, that should not be overridden for human benefit.
The protection of participants' identities in an investigation, so that no response or data can be linked to a named or identifiable person.
Analysis of variance: a statistical test that compares the means of three or more groups by comparing the variation between groups with the variation within them.
The complete absence of dissolved oxygen in water or sediment, in which only anaerobic microorganisms can survive.
A proposed geological epoch in which human activity has become the dominant influence on Earth's environment, climate and life, causing rapid environmental change and species extinction.
An environmental perspective that views humankind as the central and most important element of existence, valuing nature mainly for what it provides to people; it includes careful management and stewardship views.
Caused or produced by human activities, such as the carbon dioxide released by burning fossil fuels, as opposed to arising from natural processes.
The part of the Earth system made or modified by humans, including cities, farmland, infrastructure, industry and the flows of materials they create.
A chemical coating, often containing copper or other biocides, applied to nets, cages and boat hulls to stop algae, barnacles and other organisms growing on them.
A population policy intended to lower the birth rate, for example by providing contraception, setting limits on family size or giving incentives for smaller families.
A predator at the top of a food chain that has no natural predators of its own as an adult, such as the wolf, lion or tiger.
The faulty argument that something is good or right because it is natural, or bad or wrong because it is unnatural.
The farming of aquatic organisms, including fish, molluscs, crustaceans and aquatic plants, with intervention in the rearing process such as stocking, feeding and protection from predators.
A food production system that combines raising fish with growing plants in water, in which fish waste supplies nutrients to the plants and the plants clean the water returned to the fish.
A body of permeable rock or sediment that holds groundwater and lets it flow, so that water can be stored in it and abstracted from wells and boreholes.
The injection of surplus water, such as treated river water or wastewater, into an aquifer through wells for storage, and its pumping back out through the same wells when it is needed.
A farming system that grows crops, such as cereals, vegetables or oilseeds, on cultivated land rather than raising livestock.
A soil of hot deserts and dry shrublands, low in organic matter, often with layers of calcium carbonate, gypsum or salts because little leaching occurs.
The deliberate addition of water to an aquifer at a rate faster than natural recharge, for example from infiltration basins or injection wells, to replenish groundwater.
The deliberate choice by humans of which individual plants or animals breed, so that desired characteristics become more common over generations; also called selective breeding.
A legally binding agreement signed in 2002 by the members of the Association of Southeast Asian Nations to prevent and monitor land and forest fires and cooperate on the resulting smoke haze.
One of the four broad skills an assessment tests: knowledge and understanding (AO1), application and analysis (AO2), evaluation and synthesis (AO3) and the use of investigative skills (AO4).
The Atlantic part of the thermohaline circulation: warm, salty surface water flows north, cools and sinks in the North Atlantic, and returns south as cold deep water.
The layer of gases held around the Earth by gravity, forming the boundary between the Earth and space and the outer limit of the biosphere.
A planetary boundary process covering the amount of fine particles added to the atmosphere by human activity, which affects climate, rainfall patterns and health.
The large-scale movement of air around the Earth that transfers heat from the equator towards the poles, driven by unequal heating of the Earth's surface.
An organism that synthesises its own organic compounds from inorganic carbon and other elements, using energy from light or from inorganic chemical reactions.