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Definitions for chemical names, units, technical terms, and regional groupings recognized in international treaties are provided below, along with explanatory notes on impacts, vulnerability and adaptation, theory, predictions, forecasts and scenarios, and the IPCC suite of scenarios. Sources for the definitions are provided at the end of the book. Chemical names CCl4 Carbon tetrachloride. CFC Chlorofluorocarbon – covered under the 1987 Montreal Protocol on Substances that Deplete the Ozone Layer and used for refrigeration, air conditioning, packaging, insulation, solvents, or aerosol propellants. Since they are not destroyed in the lower atmosphere, CFCs drift into the upper atmosphere where, given suitable conditions, they break down ozone. These gases are being replaced by other compounds, including HCFCs and HFCs, which are greenhouse gases covered under the Kyoto Protocol. CH4 Methane. CO2 Carbon dioxide. CO2e Carbon dioxide equivalent. See under Technical terms. Halocarbons Compounds containing carbon and one or more of the three halogens: fluorine, chlorine, and bromine, including the greenhouse gases CFCs, CCl4, and HFCs. HCFC Hydrochlorofluorocarbon. HFC Hydrofluorocarbon. N2O Nitrous oxide. O3 Ozone in the lower atmosphere (troposphere) that acts as a greenhouse gas. It is created both naturally and by photochemical reactions involving gases resulting from human activities (“smog”). In the stratosphere, ozone is created by the interaction between solar ultraviolet radiation and molecular oxygen (O2). In the upper atmosphere (stratosphere) ozone plays a decisive role in the stratospheric radiative balance. Its concentration is highest in the ozone layer. Depletion of stratospheric ozone results in increased ultraviolet radiation. Units GW Gigawatt. GWth Gigawatt thermal. micron One millionth of a meter. Tonnes Metric tons, equivalent to 1,000 kg or 2,204.62 lb. A gigatonne is one billion (109) tonnes. Technical terms Anaerobic A life or process that occurs in, or is not destroyed by, the absence of oxygen. Anthropogenic Resulting from or produced by human beings. Calving The breaking away of a mass of ice from a floating glacier, ice front, or iceberg. Carbon dioxide equivalent (CO2e) A measure used to compare the emissions from various greenhouse gases, based on their global warming potential (GWP). The carbon dioxide equivalent for a gas is derived by multiplying the tonnes of the gas by the associated GWP. Carbon equivalent A measure used to compare the emissions of different greenhouse gases, based on their global warming potential (GWP). Convert from CO2 to carbon by multiplying by 12/44. Carbon sequestration The removal and storage of carbon from the atmosphere in carbon sinks. Carbon sink Reservoirs for carbon, such as forests and oceans, processes, activity or mechanisms that store more carbon than they release. CDM Defined in Article 12 of the Kyoto Protocol, the Clean Development Mechanism is intended to meet two objectives: (1) to assist Parties not included in Annex I in achieving sustainable development and in contributing to the ultimate objective of the convention; and (2) to assist Parties included in Annex I in achieving compliance with their quantified emission limitation and reduction commitments. Climate In a narrow sense this is usually defined as the “average weather” or the statistical description of the mean and variability of relevant quantities over a period of time ranging from months to thousands or millions of years. The classical period is 30 years, as defined by the World Meteorological Organization (WMO). The relevant quantities are most often surface variables such as temperature and precipitation. Climate in a wider sense is the state of the climate system. Climate change A statistically significant variation in either the mean state of the climate or in its variability, persisting for an extended period (typically decades or longer). Climate change may be due to natural internal processes or external radiative forcing, or to persistent anthropogenic changes in the composition of the atmosphere or in land use. The UNFCCC, in its Article 1, defines it as: “a change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over
Definition of Key Terms
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comparable time periods.” This Atlas generally follows the UNFCCC’s distinction between “climate change” attributable to human activities altering the atmospheric composition, and “climate variability” attributable to natural causes. Although often used to mean climate change, global warming is only one aspect of this – the increase in global mean temperature. COP Conference of Parties to the UNFCCC. Coral bleaching The paling in color of corals resulting from a loss of symbiotic algae, in response to abrupt changes in temperature, salinity, and turbidity. Cryosphere Component of the climate system consisting of all snow, ice, and permafrost on and beneath the surface of the earth and ocean. Ecosystem A system of interacting living organisms together with their physical environment, which can range from very small areas to the entire Earth. El Niño/Southern Oscillation A climate pattern characterized by variations in the temperature of the surface of the tropical eastern Pacific Ocean (warming or cooling, known as El Niño and La Niña respectively) and air surface pressure in the tropical western Pacific (the Southern Oscillation). Occurs roughly every five years. Emissions Reduction Units Equal to 1 tonne of carbon dioxide emissions reduced or sequestered arising from a Joint Implementation (defined in Article 6 of the Kyoto Protocol) project calculated using the global warming potential (GWP). Fugitive emissions Intentional or unintentional releases of gases from anthropogenic activities such as the processing, transmission or transportation of gas or petroleum. Geothermal Literal meaning: “Earth” plus “heat”. To produce electric power from geothermal resources, heat from underground sources is tapped by wells and the steam fed through turbines. Glacier A mass of land ice flowing downhill. A glacier is maintained by accumulation of snow at high altitudes, balanced by melting at low altitudes or discharge into the sea. Global warming Increase in global mean temperature. Global warming potential (GWP) An index, describing the radiative characteristics of well-mixed greenhouse gases, that represents the combined effect of the differing times these gases remain in the atmosphere and their relative effectiveness in absorbing outgoing long-wave radiation. The GWP of carbon dioxide is 1. Greenhouse gas Gases in the atmosphere, both natural and anthropogenic, that absorb and emit radiation at specific wavelengths within the spectrum of long-wave radiation emitted by the Earth’s surface, the atmosphere, and clouds. This property causes the greenhouse effect. Water vapor (H2O), carbon dioxide (CO2), nitrous oxide (N2O), methane (CH4), and ozone (O3) are the primary greenhouse gases in the Earth’s atmosphere, but there are a number of entirely human-made greenhouse gases, such as the halocarbons and other chlorine- and bromine-containing substances, dealt with under the Montreal Protocol. Gridded data The result of converting scattered individual data points into a regular grid of calculated, hypothetical values. Also known as “raster data”. Ice sheet A mass of land ice that is sufficiently deep to cover most of the underlying bedrock topography. There are only two large ice sheets in the modern world, on Greenland and Antarctica. Ice shelf A floating ice sheet of considerable thickness attached to a coast (usually of great horizontal extent with a level or gently undulating surface); often a seaward extension of ice sheets. ICT Information and communications technology. IPCC Intergovernmental Panel on Climate Change. Established by the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) in 1988 to assess scientific, technical and socio-economic information relevant to the understanding of climate change, its potential impacts and options for adaptation and mitigation. The IPCC Fifth Assessment Report (AR5) is scheduled for release in 2013/2014, based on the results of three working groups involved in assessing the scientific basis, the impacts, adaptations and vulnerabilities, and the mitigation of climate change. JI Joint Implementation, a market-based implementation mechanism defined in Article 6 of the Kyoto Protocol, allowing Annex I countries or companies from these countries to implement projects jointly that limit or reduce emissions, or enhance sinks, and to share the Emissions Reduction Units. JI activity is also permitted in Article 4.2(a) of the UNFCCC. Kyoto Protocol to the United Nations Framework Convention on Climate Change (UNFCCC), adopted at the Third Session of the Conference of the Parties to the UNFCCC in 1997 in Kyoto, Japan. It contains legally binding commitments, in addition to those included in the UNFCCC. Countries included in Annex B of the Protocol (most countries in the Organisation for Economic Cooperation and Development, and countries with economies in transition) agreed to reduce their anthropogenic greenhouse gas emissions by at least
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5% below 1990 levels in the commitment period 2008 to 2012. The Kyoto Protocol entered into force in 2005 after Annex I