Global Warming Glossary *
Ice age - An ice age or glacial period is characterized by a long-term reduction in the temperature of the Earth's climate, resulting in growth of continental ice sheets and mountain glaciers (glaciation).
Ice cap - A dome shaped ice mass, usually covering a highland area, which is considerably smaller in extent than an ice sheet.
Ice sheet - A mass of land ice that is sufficiently deep to cover most of the underlying bedrock topography, so that its shape is mainly determined by its dynamics (the flow of the ice as it deforms internally and/or slides at its base). An ice sheet flows outward from a high central ice plateau with a small average surface slope. The margins usually slope more steeply, and most ice is discharged through fast-flowing ice streams or outlet glaciers, in some cases into the sea or into ice shelves floating on the sea. There are only three large ice sheets in the modern world, one on Greenland and two on Antarctica, the East and West Antarctic Ice Sheets, divided by the Transantarctic Mountains. During glacial periods there were others.
Ice shelf - A floating slab of ice of considerable thickness extending from the coast (usually of great horizontal extent with a level or gently sloping surface), often filling embayments in the coastline of the ice sheets. Nearly all ice shelves are in Antarctica, where most of the ice discharged seaward flows into ice shelves.
Impact assessment - The practice of identifying and evaluating, in monetary and/or non-monetary terms, the effects of climate change on natural and human systems.
Impacts - The effects of climate change on natural and human systems. Depending on the consideration of adaptation, one can distinguish between potential impacts and residual impacts. ► Potential impacts: all impacts that may occur given a projected change in climate, without considering adaptation. ► Residual impacts: the impacts of climate change that would occur after adaptation. See also aggregate impacts, market impacts, and non-market impacts.
Implementation - Implementation describes the actions taken to meet commitments under a treaty and encompasses legal and effective phases. Legal implementation refers to legislation, regulations, judicial decrees, including other actions such as efforts to administer progress, which governments take to translate international accords into domestic law and policy. Effective implementation needs policies and programs that induce changes in the behavior and decisions of target groups. Target groups then take effective measures of mitigation and adaptation.
Income elasticity (of demand) - This is the ratio of the percentage change in quantity of demand for a good or service to a one percentage change in income. For most goods and services, demand goes up when income grows, making income elasticity positive. When the elasticity is less than one, goods and services are called necessities.
Indirect aerosol effect - Aerosols may lead to an indirect radiative forcing of the climate system through acting as cloud condensation nuclei or modifying the optical properties and lifetime of clouds.
Industrial Revolution - A period of rapid industrial growth with far-reaching social and economic consequences, beginning in Britain during the second half of the eighteenth century and spreading to Europe and later to other countries including the United States. The invention of the steam engine was an important trigger of this development. The industrial revolution marks the beginning of a strong increase in the use of fossil fuels and emission of, in particular, fossil carbon dioxide. In this report the terms pre-industrial and industrial refer, somewhat arbitrarily, to the periods before and after 1750, respectively.
Infectious disease - Any disease caused by microbial agents that can be transmitted from one person to another or from animals to people. This may occur by direct physical contact, by handling of an object that has picked up infective organisms, through a disease carrier, via contaminated water, or by the spread of infected droplets coughed or exhaled into the air.
Infrastructure - The basic equipment, utilities, productive enterprises, installations and services essential for the development, operation and growth of an organization, city or nation.
Insolation - The amount of solar radiation reaching the Earth by latitude and by season. Usually insolation refers to the radiation arriving at the top of the atmosphere. Sometimes it is specified as referring to the radiation arriving at the Earth's surface. See also: Total Solar Irradiance.
Integrated Design Process of buildings - Optimizing the orientation and shape of buildings and providing high-performance envelopes for minimizing heating and cooling loads. Passive techniques for heat transfer control, ventilation and daylight access reduce energy loads further. Properly sized and controlled, efficient mechanical systems address the left-over loads. Integrated design process requires an iterative design process involving all the major stakeholders from building users to equipment suppliers, and can achieve 30-75% savings in energy use in new buildings at little or no additional investment cost.
Interglacials - The warm periods between ice age glaciations. The previous interglacial, dated approximately from 129 to 116 ka, is referred to as the Last Interglacial.
Intergovernmental Organization (IGO) - Organizations constituted of governments. Examples include the World Bank, the Organization of Economic Co-operation and Development (OECD), the International Civil Aviation Organization (ICAO), the Intergovernmental Panel on climate change (IPCC), and other UN and regional organizations. The Climate Convention allows accreditation of these IGOs to attend negotiating sessions.
International Energy Agency (IEA) - Established in 1974, the agency is linked with the OECD. It enables OECD member countries to take joint measures to meet oil supply emergencies, to share energy information, to coordinate their energy policies, and to cooperate in developing rational energy use programs.
Inter-Tropical Convergence Zone (ITCZ) - The Inter-Tropical Convergence Zone is an equatorial zonal belt of low pressure near the equator where the northeast trade winds meet the southeast trade winds. As these winds converge, moist air is forced upward, resulting in a band of heavy precipitation. This band moves seasonally.
Invasive species - A species aggressively expanding its range and population density into a region in which it is not native, often through out-competing or otherwise dominating native species.
Irrigation water-use efficiency - Irrigation water-use efficiency is the amount of biomass or seed yield produced per unit irrigation water applied, typically about 1 metric ton (~2,205 pounds) of dry matter per 100 millimeters (~4 inches) water applied.
Isostatic or Isostasy - Isostasy refers to the way in which the lithosphere and mantle respond visco-elastically to changes in surface loads. When the loading of the lithosphere and/or the mantle is changed by alterations in land ice mass, ocean mass, sedimentation, erosion or mountain building, vertical isostatic adjustment results, in order to balance the new load. This influences local apparent sea level rise.
Isohyet - A line on a map connecting locations that receive the same amount of rainfall.
Glossaries of the contributions of Working Groups I, II and III to the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report 2007.
Nakićenović, N., J. Alcamo, G. Davis, B. de Vries, J. Fenhann, S. Gaffin, K. Gregory, A. Grübler, T.Y. Jung, T. Kram, E.L. La Rovere, L. Michaelis, S. Mori, T. Morita, W. Pepper, H. Pitcher, L. Price, K. Raihi, A. Roehrl, H.-H. Rogner, A. Sankovski, M. Schlesinger, P. Shukla, S. Smith, R. Swart, S. van Rooijen, N. Victor and Z. Dadi, 2000: Emissions Scenarios: A Special Report of Working Group III of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, and New York, 599 pp.