23 of the ESS glossary’s terms, each with the part of the syllabus where you first meet it.
Electromagnetic radiation with wavelengths of about 100–400 nm, shorter than visible light, divided into UVA, UVB and UVC; its high energy can damage DNA and living cells.
A species with large habitat needs whose protection also protects many other species that share its habitat.
The range within which the true value of a measurement or result is likely to lie, arising from the limits of instruments, the method and sampling variation.
The United Nations Convention on the Law of the Sea (1982), the international treaty defining the rights and responsibilities of states in the ocean, including territorial seas and exclusive economic zones.
The international treaty agreed in 1992 whose aim is to stabilise greenhouse gas concentrations at a level that prevents dangerous human interference with the climate system.
An equilibrium from which a system, once disturbed, moves away and settles into a new and different equilibrium instead of returning.
The rising of cold, dense, nutrient-rich water from depth to the surface, replacing surface water that winds have moved away.
The presence in city air of harmful gases and particles, such as nitrogen oxides, sulfur dioxide, carbon monoxide, particulate matter and ozone, added mainly by human activities, at levels that harm health or the environment.
A built-up area with high population density and a dense, continuous cover of buildings and infrastructure, used for living, working, trade, culture and social life; cities, towns and suburbs are urban areas.
The principle of concentrating housing, jobs and services at relatively high density within a limited urban area, so that the city uses less land and distances between places are short.
An approach to urban planning that creates, protects and connects habitats such as parks, ponds, canals, allotments and wildlife corridors, so that the city supports biodiversity and natural processes.
The community of organisms living in an urban area, including people, together with the abiotic environment of buildings, soil, water, air and climate with which they interact.
The growing of plants and raising of animals for food within or close to an urban area, for example in allotments, rooftop gardens, city farms, beehives or vertical farms.
An urban area that is significantly warmer than the surrounding countryside, especially at night, because of heat-absorbing surfaces, less vegetation and evaporation, building geometry and waste heat.
The process of deciding the best use of land, buildings and infrastructure in an urban area to meet the physical, social, economic, environmental and health needs of all its stakeholders.
The spread of low-density, often car-dependent development outward from a city into the surrounding countryside, so that the urban area uses more land per person.
An urban area viewed as an interconnected system of buildings, people, other organisms, transport, energy, water, goods and services, with inputs, outputs, storages and internal flows.
The shift of population from rural to urban areas, so that a growing proportion of people live in towns and cities, together with the conversion of land into dense built-up settlement.
The value people gain from using a resource, directly (timber, fish, recreation) or indirectly through the ecosystem services it provides (flood control, pollination, carbon storage).
A form of consequentialist ethics that judges as right the action producing the greatest good or well-being for the greatest number of those affected.
Ultraviolet radiation with wavelengths of 315–400 nm; the lowest-energy ultraviolet band, most of which reaches the surface, where it causes skin ageing and contributes to skin cancer.
Ultraviolet radiation with wavelengths of 280–315 nm, mostly absorbed by stratospheric ozone; the part that reaches the surface causes sunburn, DNA damage, skin cancer and cataracts.
Ultraviolet radiation with wavelengths of 100–280 nm; the highest-energy and most damaging ultraviolet band, completely absorbed by ozone and oxygen in the upper atmosphere.