Global Warming Glossary *
Macroeconomic costs - These costs are usually measured as changes in Gross Domestic Product or changes in the growth of Gross Domestic Product, or as loss of welfare or consumption.
Malaria - Endemic or epidemic parasitic disease caused by species of the genus Plasmodium (Protozoa) and transmitted by mosquitoes of the genus Anopheles; produces bouts of high fever and systemic disorders, affects about 300 million and kills approximately 2 million people worldwide every year.
Market barriers - In the context of climate change mitigation, market barriers are conditions that prevent or impede the diffusion of cost-effective technologies or practices that would mitigate heat-trapping gas (greenhouse gas) emissions.
Market-based regulation - Regulatory approaches using price mechanisms (e.g., taxes and auctioned tradable permits), among other instruments, to reduce heat-trapping gas (greenhouse gas) emissions.
Market Exchange Rate - This is the rate at which foreign currencies are exchanged. Most economies post such rates daily and they vary little across all the exchanges. For some developing economies official rates and black-market rates may differ significantly and the market exchange rate is difficult to pin down.
Market impacts - Impacts that can be quantified in monetary terms, and directly affect Gross Domestic Product—e.g., changes in the price of agricultural inputs and/or goods. See also non-market impacts.
Mass balance (of glaciers, ice caps or ice sheets) - The balance between the mass input to the ice body (accumulation) and the mass loss (ablation, iceberg calving). Mass balance terms include the following: ► Specific mass balance: net mass loss or gain over a hydrological cycle at a point on the surface of a glacier. ► Total mass balance (of the glacier): The specific mass balance spatially integrated over the entire glacier area; the total mass a glacier gains or loses over a hydrological cycle. ► Mean specific mass balance: The total mass balance per unit area of the glacier. If surface is specified (specific surface mass balance, etc.) then ice flow contributions are not considered; otherwise, mass balance includes contributions from ice flow and iceberg calving. The specific surface mass balance is positive in the accumulation area and negative in the ablation area.
Medieval Warm Period (MWP) - An interval between AD 1000 and 1300 in which some Northern Hemisphere regionsmedi reg were warmer than during the Little Ice Age that followed.
Meningitis - Inflammation of the meninges (part of the covering of the brain), usually caused by bacteria, viruses or fungi.
Meridional Overturning Circulation (MOC) - Meridional (northsouth) overturning circulation in the ocean quantified by zonal (east-west) sums of mass transports in depth or density layers. In the North Atlantic, away from the subpolar regions, the MOC (which is in principle an observable quantity) is often identified with the Thermohaline Circulation (THC), which is a conceptual interpretation. However, it must be borne in mind that the MOC can also include shallower, wind-driven overturning cells such as occur in the upper ocean in the tropics and subtropics, in which warm (light) waters moving poleward are transformed to slightly denser waters and subducted equatorward at deeper levels.
Methane (CH4) - Methane is one of the six heat-trapping gases (greenhouse gases) to be mitigated under the Kyoto Protocol. It is the major component of natural gas and associated with all hydrocarbon fuels, animal husbandry and agriculture. Coal-bed methane is the gas found in coal seams.
Methane recovery - Methane emissions, e.g., from oil or gas wells, coal beds, peat bogs, gas transmission pipelines, landfills, or anaerobic digesters, are captured and used as a fuel or for some other economic purpose (e.g., chemical feedstock).
Microclimate - Local climate at or near the Earth's surface. See also climate.
Millennium Development Goals - A list of ten goals, including eradicating extreme poverty and hunger, improving maternal health, and ensuring environmental sustainability, adopted in 2000 by the UN General Assembly, i.e., 191 States, to be reached by 2015. These goals commit the international community to an expanded vision of development, and have been commonly accepted as a framework for measuring development progress.
Mitigation - A human intervention to reduce the human-induced forcing of the climate system; it includes strategies to reduce heat-trapping gas (greenhouse gas) sources and emissions and enhancing heat-trapping greenhouse gas) sinks.
Mixed layer - The upper region of the ocean, well mixed by interaction with the overlying atmosphere.
Modes or patterns of climate variability - Natural variability of the climate system, in particular on seasonal and longer time scales, predominantly occurs with preferred spatial patterns and time scales, through the dynamical characteristics of the atmospheric circulation and through interactions with the land and ocean surfaces. Such patterns are often called regimes, modes or teleconnections. Examples are the North Atlantic Oscillation (NAO), the Pacific-North American pattern (PNA), the El Niño Southern Oscillation (ENSO), the Northern Annular Mode (NAM; previously called Arctic Oscillation, AO) and the Southern Annular Mode (SAM; previously called the Antarctic Oscillation, AAO).
Monsoon - A monsoon is a tropical and subtropical seasonal reversal in both the surface winds and associated precipitation, caused by differential heating between a continental-scale land mass and the adjacent ocean. Monsoon rains occur mainly over land in summer.
Montane - The biogeographic zone made up of relatively moist, cool upland slopes below the sub-alpine zone that is characterized by the presence of mixed deciduous at lower and coniferous evergreen forests at higher elevations.
Montreal Protocol - The Montreal Protocol on Substances that Deplete the Ozone Layer was adopted in Montreal in 1987, and subsequently adjusted and amended in London (1990), Copenhagen (1992), Vienna (1995), Montreal (1997) and Beijing (1999). It controls the consumption and production of chlorine- and bromine-containing chemicals that destroy stratospheric ozone, such as chlorofluorocarbons, methyl chloroform, carbon tetrachloride and many others.
Morbidity - Rate of occurrence of disease or other health disorders within a population, taking account of the age-specific morbidity rates. Morbidity indicators include chronic disease incidence/prevalence, rates of hospitalization, primary care consultations, disability-days (i.e., days of absence from work), and prevalence of symptoms.
Morphology - The form and structure of an organism or land-form, or any of its parts.
Mortality - Rate of occurrence of death within a population; calculation of mortality takes account of age-specific death rates, and can thus yield measures of life expectancy and the extent of premature death.
Multi-gas - Next to CO2 also the other heat-trapping gases (greenhouse gases), including methane, nitrous oxide and fluorinated gases, are taken into account in e.g. achieving reduction of emissions (multi-gas reduction) or stabilization of concentrations (multi-gas stabilization).
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.