Home
header image

Glossary

AAdaptation to climate change
Actions to reduce the vulnerability of natural and human systems to the negative impacts of anticipated human-induced climate change. This can be in response to actual or expected climatic stimuli or their effects, which moderates harm or exploits beneficial opportunities. Various types of adaptation can be distinguished such as planned, reactive, anticipatory and spontaneous (autonomous). Spontaneous (autonomous) adaptation occurs mainly in natural systems, for example, increasing sediment along coastlines in response to erosion.
Adapted from UKCIP website, 2011 (http://www.ukcip.org.uk/glossary/)
Adaptation Sub-Committee
The Adaptation Sub-Committee (ASC) is a sub-committee of the Committee on Climate Change (CCC), established under the UK’s Climate Change Act 2008.  The ASC provides expert advice and scrutiny through the CCC, ensuring that the Government’s programme for adaptation enables the UK to prepare effectively for the impacts of climate change.
Committee on Climate Change, http://www.theccc.org.uk/adaptation/about-the-asc
Adaptive capacity
Inherent capacity of a system or population to adjust to climate impacts or climate change, to moderate potential damages, exploit opportunities, and cope with the consequences.
UKCIP website, 2011 (http://www.ukcip.org.uk/glossary/)
BBaseline
The baseline or reference climate is conventionally a 30-year average, relating to either climate observations or to model-simulated data. For UKCP09 the period 1961–1990 was selected as the baseline climate, meaning that all climate change projections are given relative to the modelled climate during this period.
UK Climate Projections 09 website, Index, http://ukclimateprojections.defra.gov.uk/content/view/533/690/
Brownfield land
See previously developed land
CCentral Estimate (see also probability levels)
The UKCP09 probabilistic climate projections are reported as a central estimate when referring to a projected change that has equal probability of being exceeded and not being exceeded. This can also be reported as in the 50th percentile.
UK Climate Projections 2009, Index. http://ukclimateprojections.defra.gov.uk/content/view/534/690/
Climate
Climate is typically defined as the average weather over a period of time, usually 30 years. These quantities are most often surface variables such as temperature, precipitation, and wind. Climate in a wider sense is the state, including a statistical description, of the climate system.
UKCIP website, 2011 (http://www.ukcip.org.uk/glossary/)
Climate projections
Climate projections expressed in terms of absolute values (as opposed to the relative value expressed in future climate change projections). It is a projection of the response of the climate system to scenarios based upon climate model simulations and past observations. Climate change projections are expressed as an absolute future climate, for example, that future average daily temperature in the summer will be 34°C for a given location, time period and emissions scenario.
UK Climate Projections 2009, Index. http://ukclimateprojections.defra.gov.uk/content/view/534/690/
Climate change projections (also see scenarios)
Climate projections expressed in terms of the difference between the absolute future climate and a baseline climatology. It is a projection of the response of the climate system to a set of scenarios based upon climate model simulations and past observations. Climate change projections are expressed as departures from a baseline climatology, for example, that future average daily temperature in the summer will be 2°C warmer for a given location, time period and emissions scenario.
UK Climate Projections 2009, Index. http://ukclimateprojections.defra.gov.uk/content/view/534/690/
Climate feedback
An initial process in the climate leads to a change in another process in the climate, which in turn influences the initial one. A positive feedback intensifies the original process, and a negative feedback reduces it. A warming climate could increase the release of carbon dioxide from soils. Since carbon dioxide is a greenhouse gas, the additional release of carbon dioxide would further warm the climate — this is an example of a positive feedback.
Met Office, Climate Change Glossary, 2010. http://www.metoffice.gov.uk/climate-change/guide/glossary
Climate system
The climate system is the highly complex system consisting of five major components: the atmosphere, the hydrosphere, the cryosphere, the land surface and the biosphere, and the interactions between them. The climate system evolves in time under the influence of its own internal dynamics and because of external forcings such as volcanic eruptions, solar variations and anthropogenic forcings such as the changing composition of the atmosphere and land-use change.
Adapted from IPCC, 2007, AR4, synthesis report, p. 79
Cooling degree day
An annual measure of the extent to which temperatures suggest that buildings may require some form of cooling (e.g. air conditioning), based on the daily temperature being above a specified threshold (22°C).
UKCIP website, 2011 (http://www.ukcip.org.uk/glossary/)
Cost-benefit analysis
A term used to describe the appraisal of the merits associated with each option by quantifying in monetary terms as many costs and benefits as possible, including items for which the market does not provide a satisfactory measure of value. It is designed to help one select the option which offers the greatest excess of benefits over costs.
UKCIP website, 2011 (http://www.ukcip.org.uk/glossary/)
Critical infrastructure
Critical infrastructure (CI) consists of those physical and information technology facilities, networks, services and assets which, if disrupted or destroyed, have a serious impact on the health, safety, security or economic well-being of citizens or the effective functioning of governments
European Commission, European Programme for Critical Infrastructure Protection (EPCIP), http://europa.eu/legislation_summaries/justice_freedom_security/fight_ag...
Critical threshold
The point in a system at which sudden or rapid change occurs
UKCIP website, 2011 (http://www.ukcip.org.uk/glossary/)
EEvapotranspiration
The process by which water is transferred from the land to the atmosphere by evaporation from the soil and other surfaces and by transpiration (the loss of water vapour) from plants.
Evapotranspiration from vegetation provided by green spaces consumes a significant proportion of the available heat energy in the atmosphere. This energy is used to convert water in the leaves into water vapour, which is then transpired through the trees. Evapotranspiration can reduce peak summer temperatures by 5°C.
Adapted from Oxford Dictionaries Online, http://oxforddictionaries.com/definition/evapotranspiration
Exceedance
When related to drainage systems, exceedance refers to the conveyance capacity of a minor drainage system. When it is surpassed, surface flooding occurs. The excess flow of water that appears on the surface is known as the exceedance flow. Rainfall events that result in exceedance flows are considered to be extreme events.
Adapted from CIRIA. 2006. Designing for exceedance in urban drainage – good practice, CIRIA C635.
Exposure
The degree to which a system (e.g. community or built environment) can come into contact with a given hazard (such as flooding or heat waves). It not only corresponds to a geographical location, but also of the characteristics of the surroundings which may exacerbate or limit a hazard.
Kazmierczak and Handley 2011, p. 5
Extreme weather event
Extreme weather describes weather phenomena that are at the extremes of the historical distribution, especially severe or unseasonal weather.
UKCIP website, 2011 (http://www.ukcip.org.uk/glossary/)
FFlood Map
The Flood Map is a multi-layered map which provides information on flooding from rivers and the sea for England and Wales. The Flood Map also has information on flood defences and the areas benefiting from those flood defences. The Flood Map is designed to increase awareness among the public, local authorities and other organisations of the likelihood of flooding, and to encourage people living and working in areas prone to flooding to find out more and take appropriate action.
The Flood Map can also be used by those people who wish to apply for planning permission in England to see whether the site they plan to develop is in a flood risk area. It does not provide information on flood depth, speed or volume of flow. It does not show flooding from other sources, such as groundwater, direct runoff from fields, or overflowing sewers. The Environment Agency, 2011, http://www.environment-agency.gov.uk/homeandleisure/31662.aspx
Flood zone
Flood zones refer to the probability of river or sea flooding for a given area in the UK as set out in PPS 25 ‘Development and Flood Risk’. Zone 1 is low probability and is land assessed as less than 1 in 1000 annual probability of river or sea flooding in any year (<0.1%). Flood zone 2 is medium probability; This zone comprises land assessed as having between a 1 in 100 and 1 in 1000 annual probability of river flooding (1% – 0.1%) or between a 1 in 200 and 1 in 1000 annual probability of sea flooding (0.5% – 0.1%) in any year. Flood zone 3a is high probability and comprises land assessed as having a 1 in 100 or greater annual probability of river flooding (>1%) or a 1 in 200 or greater annual probability of flooding from the sea (>0.5%) in any year. Flood zone 3b is ‘functional floodplain’ This zone comprises land where water has to flow or be stored in times of flood.
CLG, Planning Policy Statement Number 25, Development and Flood Risk, Revised March 2010. http://www.communities.gov.uk/documents/planningandbuilding/pdf/planning...
Fluvial flooding
See river flooding.
GGeographic Information System (GIS)
A Geographic Information System is a powerful set of tools for collecting, storing, retrieving at will, transforming, analysing and displaying spatial data
Burrough, P. A. and McDonnell, R. A. 1998. Principles of Geographical Information Systems. Oxford: Oxford University Press, p. 11.
Green Infrastructure
Green Infrastructure is a strategically planned and delivered network comprising the broadest range of high quality green spaces and other environmental features. It should be designed and managed as a multifunctional resource capable of delivering those ecological services and quality of life benefits required by the communities it serves and needed to underpin sustainability. Its design and management should also respect and enhance the character and distinctiveness of an area with regard to habitats and landscape types. Green Infrastructure includes established green spaces and new sites and should thread through and surround the built environment and connect the urban area to its wider rural hinterland. Consequently it needs to be delivered at all spatial scales from sub-regional to local neighbourhood levels, accommodating both accessible natural green spaces within local communities and often much larger sites in the urban fringe and wider countryside .
Natural England(2009) Green Infrastructure Guidance , p. 7
Greenhouse Gases
A gas within the atmosphere which absorbs and emits energy radiated by the Earth. Carbon dioxide (CO2) is the most important greenhouse gas being emitted by humans. The greenhouse effect is natural and without it the Earth would be considerably colder. The primary greenhouse gases are: Water vapour (H2O), carbon dioxide (CO2), nitrous oxide (N2O), methane (CH4) and ozone (O3).
UKCIP website, 2011 (http://www.ukcip.org.uk/glossary/)
HHazard
The extent, severity and probability of a phenomenon (for example flooding or heat waves) that can cause harm to a system.
Kazmierczak and Handley 2011, p. 5
Heat wave
A prolonged period of excessively hot weather, which may be accompanied by high humidity. There is no universal definition of a heatwave; the term is relative to the climate in the area with a locally identified threshold temperature. For Manchester the threshold is 30°C by day and 15°C by night.
UK Climate Projections 2009, Index. http://ukclimateprojections.defra.gov.uk/content/view/534/690/ and NHS Manchester. 2010. Heatwave plan 2010. NHS Manchester, Manchester.
Heating degree day
An annual measure of the extent to which daily temperatures suggest that buildings may require some form of space heating, based on the daily temperature being below a certain threshold (15.5ºC).
UKCIP website, 2011 (http://www.ukcip.org.uk/glossary/)
IIntergovernmental Panel on Climate Change
The Intergovernmental Panel on Climate Change (IPCC) is an international forum of experts brought together by the United Nations to undertake periodical assessments addressing how climate will change, what its impacts may be and how we can respond. It was originally formed in 1988 and published its Fourth Assessment Report (AR4) in 2007.
UKCIP website, 2011 (http://www.ukcip.org.uk/glossary/)
MMaladaptation
An adaptation action or investment that enhances vulnerability to climate change impacts rather than reducing them. For example, installing air conditioning is a legitimate form of climate change adaptation; however, using it will increase the amount of greenhouse gas released into the atmosphere and exacerbate climate change.
Adapted from UKCIP website, 2011 (http://www.ukcip.org.uk/glossary/)
Mean
A statistical term, the mean refers to the arithmetic average. It is calculated by adding all values and then dividing by the number of values.
Adapted from Leech, Caplovitz Barrett and Morgan. 2005. SPSS for Intermediate Statistics: use and interpretation, London, Routledge, 2005. p. 18
Mitigation
Reducing greenhouse gas emissions in order to slow or stop global climate change.
UKCIP website, 2011 (http://www.ukcip.org.uk/glossary/)
PPeak Oil
‘Peak Oil’ refers to oil production reaching an all-time high and the subsequent decline in production volumes. Thus, after the ‘peak’, the rate of total world oil production volumes cannot increase but will decline.
Hirsch, Bezdek, Wendling 2005. PEAKING OF WORLD OIL PRODUCTION: IMPACTS, MITIGATION, & RISK MANAGEMENT, p. 11, http://www.netl.doe.gov/energy-analyses/pubs/Oil_Peaking_NETL.pdf
Peri-urban
The transition zone, or interaction zone, where urban and rural activities are juxtaposed, and landscape features are subject to rapid modifications, induced by human activity.  These critical areas of land cover change, leading to transformations in the hydrological, ecological, geomorphological and socio-economic systems, are often neglected by both rural and urban administrations. However, as cities develop, much of their growth is located in such areas.
Douglas. 2006. Peri-urban ecosystems and societies: Transitional zones and contrasting values. In: McGregor, D., Simon, D. and Thompson, D, editor(s). The Peri-Urban Interface. London: Earthscan; 2006. p. 18
Pluvial Flooding
See surface water flooding
Previously Developed Land or brownfield land (PDL).
Any site that has been previously used for development of buildings or infrastructure facilities, excluding agriculture and forestry, that is no longer required for that use but where no restoration work has taken place to return the site to its previous condition or to an alternative use.
Ciria, Open Spaces website, 2012. http://www.opengreenspace.com/useful-resources/glossary/#pdl
Probability
Probability is a way of expressing knowledge or belief that an event will occur, and is concept most people are familiar with in everyday life. In mathematics, there are two types of probability. Most people are familiar with objective probability, which is the likelihood of an outcome based on empirical observations and information. The second type of probability, subjective probability, is where the likelihood of an outcome is based on the strength of belief in different outcomes.
UK Climate Projections 2009, Index. http://ukclimateprojections.defra.gov.uk/content/view/534/690/
Probabilistic climate change projections
A projection of future change in climate (relative to a baseline period) that assigns probability levels to different climate change outcomes. This projection provides a change value for the future climate, expressed as the difference from the (modelled) 1961–1990 baseline climate (as opposed to the absolute value expressed in probabilistic climate projections).
UK Climate Projections 2009, Index. http://ukclimateprojections.defra.gov.uk/content/view/534/690/
RReceptors
Receptors are systems exposed to climate change hazards (e.g. community, built environment, natural environment). Receptors represent important aspects of the exposure unit. In some cases, the exposure unit and receptor may be synonymous.
Adapted from UKCIP website, 2011 (http://www.ukcip.org.uk/glossary/)
Resilience
The ability of a social or natural system to absorb disturbances while retaining the same basic structure and ways of functioning, the capacity of self-organisation and the capacity to adapt to stress and change.
Adapted from UKCIP website, 2011 (http://www.ukcip.org.uk/glossary/)
Retrofitting
Retrofitting means to install new or modified parts or equipment, or undertake structural modifications, to existing infrastructure that were either not available or not considered necessary at the time of construction. The purpose of retrofitting in the context of climate change is generally to ensure that existing infrastructure meets new design specifications that may be required under altered climate conditions.
IPCC, 2007, AR4, synthesis report, p. 86
Risk
The EcoCities definition of risk considers three risk components in relation to their influence on systems: vulnerability, hazard and exposure. See risk triangle
Kazmierczak, A. (2012). Heat and social vulnerability in Greater Manchester: a risk-response case study. EcoCities project, The University of Manchester., p. 9
Risk triangle
The risk triangle is made up of three components: hazard, exposure and vulnerability (see separate definitions). The way that each of these components leads to a risk being realised is represented in the ‘risk triangle’.
Kazmierczak, A. (2012). Heat and social vulnerability in Greater Manchester: a risk-response case study. EcoCities project, The University of Manchester., p. 9
Kazmierczak, A. and Cavan, G. (2011). Surface water flooding risk to urban communities: Analysis of vulnerability, hazard and exposure. Landscape and Urban Planning 103(2), p. 186
River flooding (also pluvial flooding).
River flooding occurs when a watercourse cannot cope with the water draining into it from the surrounding land. This can happen, for example, when heavy rain falls on an already waterlogged catchment.
The Environment Agency, 2011. Sources of Flooding. http://www.environment-agency.gov.uk/homeandleisure/floods/31652.aspx
SScenarios
A description of a plausible future state which is not associated with an ascribed likelihood. UKCP09 uses emissions scenarios to underpin probabilistic climate projections.
Adapted from UKCIP website, 2011 (http://www.ukcip.org.uk/glossary/)
Social Infrastructure
Social infrastructure includes community facilities such as schools, libraries, health facilities, cultural and religious facilities.
RTPI,2012. http://www.rtpi.org.uk/item/4474
Special Report on Emissions Scenarios (SRES)
A report published by the IPCC which defined different future emissions pathways based on potential storylines for the future, including population, energy use etc.
UKCIP website, 2011 (http://www.ukcip.org.uk/glossary/)
Stakeholder
A group or organisation with an interest, statutory responsibility, or practical role in developing and implementing climate change adaptation strategies and related initiatives.
Carter, J. G. 2009. Stakeholder Mapping for Climate Change Adaptation. EcoCities project, University of Manchester, Manchester, UK, p. 7
Standard deviation
A statistical measure of the spread of values in a dataset about their mean.
UK Climate Projections 2009, Index. http://ukclimateprojections.defra.gov.uk/content/view/534/690/
Surface water flooding (also pluvial flooding)
Occurs when heavy rainfall overwhelms the drainage capacity of the local area.  It is difficult to predict and pinpoint, much more so than river or coastal flooding.
The Environment Agency, 2011. Sources of Flooding. http://www.environment-agency.gov.uk/homeandleisure/floods/31652.aspx
TThermal comfort
Describes a person’s state of mind in terms of whether they feel too hot or too cold. Environmental factors (such as humidity and sources of heat in the workplace) combine with personal factors (such as the clothing a person is wearing and how physically demanding their work is) to influence what is called their ‘thermal comfort’.
Health and Safety Executive, UK, 2012. http://www.hse.gov.uk/temperature/thermal/
Threshold
The level of strength in an ecological, economic or other system at which process at which sudden or rapid change occurs and new properties emerge, altering relationships or predictions that apply at lower levels.
UK Climate Projections 2009, Index. http://ukclimateprojections.defra.gov.uk/content/view/534/690/
Time-slice (or time period)
Any period of time used as a representative in the future. In the UKCP09 scenarios, three 30-year time-slices were used, with the climate change scenario results reported as an average for each: the 2020s represents the projected average climate for the period 2011-2040; the 2050s represents the projected average climate for the period 2041-2070; the 2080s represents the projected average climate for the period 2071-2100
UKCIP website, 2011 (http://www.ukcip.org.uk/glossary/)
UUncertainty
Uncertainty refers to a state of having limited knowledge. Uncertainty can result from lack of information or from disagreement over what is known or even knowable. Uncertainty may arise from many sources, such as quantifiable errors in data, or uncertain projections of human behaviour. Uncertainty can be represented by quantitative measures or by qualitative statements.
UKCIP website, 2011 (http://www.ukcip.org.uk/glossary/)
Urban heat island
The urban heat island effect causes urban areas to become several degrees hotter than surrounding rural areas. In hot summers cities will become increasingly uncomfortable to live in.
CABE, 2011. http://webarchive.nationalarchives.gov.uk/20110118095356/http:/www.cabe....
VVulnerability to climate change
Vulnerability refers to the intrinsic characteristics of the systems (human populations, natural ecosystems, built environment, or others), which are influenced by climate change. Vulnerability defines the extent to which these receptors are susceptible to harm from, or unable to cope with, hazards.
Kazmierczak and Handley 2011, The vulnerability concept: use within GRaBS p. 5
WWeather
Weather refers to the state of the atmosphere with regard to temperature, cloudiness, rainfall, wind, and other meteorological conditions.
UKCIP website, 2011 (http://www.ukcip.org.uk/glossary/)
Weather Generator
A Weather Generator is a statistical method of creating projections of future daily (or sub-daily) climate that are consistent with climate change projections for longer temporal averaging periods (e.g. monthly or seasonal). It DOES NOT generate weather forecasts for specific future dates!
UKCIP website, 2011 (http://www.ukcip.org.uk/glossary/)