| CLIMATE CHANGE IN CONTEXT | PREVIOUS | | | NEXT |
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| Ablation | Loss of ice in a glacier due to evaporation and melting |
| Abrasion | Wearing away of rocks by the action of wind, water or ice carrying particles of dust and sand. A process similar to sandpapering |
| Abyssal | Relating to the deep areas of the earth and oceans and the organisms inhabiting those environments |
| Accumulation | The addition of ice and snow to a glacier |
| Advection | The transfer of heat, cold, or other atmospheric properties by the horizontal movement of a mass of air |
| Albedo | The amount of light reflected from a surface. Snow has a high albedo |
| Alluvial fan deltas | Fan shaped mass of loose rock material deposited on a flood plain |
| Altitude | The vertical distance above a reference point (usually sea level) |
| Ancillary benefits | Positive side effects of policies or actions |
| Angiosperm | Flowering plants in which the seeds are enclosed in fruit |
| Angstrom | Unit of wavelength for electromagnetic radiation. 1 Angstrom Unit is equal to one ten-billionth of a meter. (10-10 meters) |
| Annex I countries | Industrialized and developing countries expected to participate in the Kyoto Agreement. These countries are committed to returning their emissions outputs to 1990 levels |
| Anthropogenic | Changes in the natural world resulting from or influenced by human activities |
| Anthropogenic forcing | The activities of humankind which cause changes in the structure and processes of the environment |
| Aphelion | Phase in orbit when the Earth is farthest from the sun |
| Aquifer | A layer of porous rock between layers of non-porous (impermeable) rock. This structure allows water to move great distance through this ‘pipeline’, sometimes emerging at a shoreline (coastal aquifer) or floodplain (floodplain aquifer) |
| Arctic Oscillation | An atmospheric circulation pattern in which the atmospheric pressure over the polar areas varies in opposition with that over the middle latitudes on time scales varying from weeks to decades |
| Asthenosphere | The zone of hot rock, believed to be in a plastic condition, underlying the solid lithosphere (the Earth’s crust) |
| Atmosphere | The layers of air which surrounds the Earth which consist mainly of the permanent gases such as nitrogen, oxygen, argon and helium and variable gases such as ozone, sulfur dioxide, and carbon dioxide (about 0.04%). The atmosphere decreases in density and air pressure as elevation increases, becoming almost non-existant at altitudes above 100 kilometers |
| Atoll | Coral reef forming a circle around a central lagoon |
| Australasia | The islands of the southern Pacific Ocean including Australia, New Zealand, New Guinea and adjacent islands |
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| Bacteriocin | Toxin produced by one bacteria, which kills another, usually in a related class |
| Basal slip | Movement of an entire glacier over underlying ground surface |
| Batholith | Large body of intrusive igneous rock, usually granite, forming deep underground |
| Bedrock | Solid rock which lies below the soil. On the prairies it may be several feet below the surface; on hillsides, only a few inches |
| Beheaded stream | Stream that has had its flow captured by another stream |
| Benthos | The biographic region at the bottom of a sea, ocean, or lake, and the organisms living there |
| Bioaccumulation | The increase in the concentration of poisons in animal tissue towards the top of the food chain |
| Biogeochemistry | A branch of geochemical dealing with the relationship of plants and animals to the global distribution by chemical elements |
| Biomass | The total dry mass of an animal or plant population |
| Biosphere | Area of the Earth’s crust, ocean, and atmosphere where life is found |
| Braided stream | A stream or river that splits into smaller channels that rejoin further downstream |
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| Calving | Breaking off of pieces of glaciers and ice shelves that then become icebergs |
| Canyon | Deep, steep-sided valley created by river erosion |
| Carbon 14 | Atmospheric carbon dioxide contains a constant proportion of radioactive 14C, formed by cosmic radiation. Living organisms absorb this unstable isotope in the same proportion. The proportion of stable 12C to the residual 14˚C indicates the period elapsed since death |
| Carbon sinks | Structures or processes able to absorb carbon dioxide, thus removing it from the atmosphere |
| Cardiovascular disease | Disease of the heart and blood vessels |
| Cargo dirigibles | Large gas-filled (helium) airships proposed to transport heavy loads in wilderness areas |
| Catalytic Reactions | Reactions that are affected by the presence of an agent (catalyst) which is itself unaffected by the reaction |
| Cataracts | Clouding of the lens of the eye due to degeneration |
| Cavity | A natural recess or chamber with an entrance at the surface |
| CFCs | A hydrocarbon in which some or all of the hydrogen atoms have been replaced by chlorine or fluorine. It has a depletive effect on stratospheric ozone |
| Cholera | An acute bacterial infection spread by infected food and water. The symptoms include severe vomiting and diarrhea, painful cramps and drying of body tissue |
| Circumpolar | High latitude regions surrounding the poles |
| Climate | Pattern of weather conditions of a place or region, based on daily weather records over a period of time (usually 20 years) |
| Confluence | Point at which two or more streams join to form a larger single stream |
| Continental Drift | Slow movement of the continents on the surface of the earth |
| Convection rain | Precipitation caused by the warming of moist air by thermal conduction from the heated land surface. The moist warm air rises, cools, and forms clouds which drop heavy torrential rain |
| Convection | Heat transfer from place to place within a gas or liquid |
| Cordilleran type | Mountain system consisting of series of parallel ranges or ridges (e.g. Rockies or Andes) |
| Craton | Large stable block of the Earth’s crust, relatively unaffected by tectonic activity, typically Precambrian in age (over 500 million years old) |
| Crevasse | A vertical crack or fissure often deep and wide, a glacier or ice sheet |
| Cryosphere | The region at the Earth’s surface that is frozen throughout the year |
| Cuesta (or escarpment) | Hill or ridge with a steep slope on one side and gentler slope (or ‘dip’) on the other |
| Cycads | Gymnosperm plants featuring broad unbranched stems with large leaves at the end |
| Cyclone | A circular movement of winds revolving around a low pressure centre |
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| Delta | Triangular shaped formation of sediment deposited at the mouth of the river |
| Dendrochronology | The analysis of tree rings to determine past climate conditions |
| Denuded | Bedrock exposed by the erosion of overlying material |
| Direct relationship | Is a positive relationship between two variables such that as one variable increases, so does the other |
| Discernible | Able to be sensed |
| Drift | Material deposited by drifting icebergs. Loose material (sand, gravel, boulder, clay, etc.) deposited by glacier or melt water of glaciers |
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| Ecological thinking | A sensitivity to the need to preserve the balances in nature and the relationships among the natural systems of the Earth |
| El Niño | Intense and prolonged warming of the eastern Pacific Ocean every few years, producing unusual weather |
| Electromagnetic spectrum | The range of wavelengths from gamma rays, through x-rays ultra-violet, visible light, infrared and radio waves |
| Emissivity | The radiation emitted by an object compared to that of a perfect black-body radiator at the same temperature |
| Encephalitis | A disease characterized by the progressive destruction of the nerve fibres in the brain, causing paralysis |
| Endemic | A species or family confined to a particular region and thought to have originated there |
| Endothermy | The absorption of heat energy |
| ENSO | El Niño Southern Oscillation. This is the strongest natural fluctuation of climate on interannual time scales |
| Environment | The physical, chemical, and biological surroundings of an object |
| Equatorial current | A low latitude surface ocean current, generally flowing east to west |
| Equilibrium Model | A representation of the relationships between various forces |
| Esker | Long narrow ridge formed by a subglacial stream carrying sand and gravel |
| Estuaries | An inlet of the sea at the mouth of a river |
| Eukaryotic | Higher or more complex organisms (animals, plants, and fungi). The cells have nuclear membranes |
| Eutrophication | Decay of organic matter in a lake, with resultant loss of oxygen in the water |
| Evapotranspiration | The total water loss from a particular area being the sum of evaporation from the soil and transpiration from vegetation |
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| Fault | A fracture or break in a series of rocks along which some displacement has taken place |
| Fauna | A collective term denoting the animals occurring in a particular region or period |
| Feedback loop | The path by which some of the output of a system is returned to the input |
| Firn (or névé) | Granular snow in a state halfway between snow and ice, subsequently compacted to form ice |
| Foraminifera | Single-celled organisms which produce a protective shell of limestone or chiton |
| Forearc and backarc | A sedimentary basin developed in the gap between a volcanic arc and its subduction zone |
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| Gabbro | A coarse grained group of rocks formed within the Earth’s crust |
| Gamma-rays | Electromagnetic radiation of high quantum energy emitted after nuclear reactions or by radioactive atoms |
| GDP | Gross Domestic Product. The sum total of all goods and services produced in a country in one year |
| Geological | The study of the planet earth and the physical and chemical process affecting its structures |
| Germination | The beginning of growth in a seed, spore, or zygote following a dormant period |
| Glacial trough | Feature formed when a glacier widens and deepens a valley that was originally V-shaped. The valley becomes much deeper and U-shaped. The upper slopes tend to be very steep, while the lower have a gentler descent |
| Gondwanaland | Southern part of Pangaea, the great land mass prior to the drifting of the continents (which began about 200 million years ago). It consisted of Africa, Australia, India and Antarctica |
| Gorge | Narrow steep-sided valley formed by river erosion |
| Graben | A rift valley, formed by the subsiding of rock between two parallel faults |
| Gradient | Slope of the land, shown on contour maps by the distance between the contour lines |
| Green roof projects | The planting of vegetation on rooftops of buildings |
| Greenhouse effect | Warming of the lower levels of the atmosphere as a result of the retention and radiation of solar heat |
| Greenhouse gas emissions | Gases such as carbon dioxide and methanol that increase global temperatures by trapping solar electromagnetic radiation |
| Gymnosperm | A plant where seeds are not enclosed within an ovule or fruit (e.g. conifers) |
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| Heinrich events | Episodes during the last ice age with ice- rafted debris deposited on the sea floor |
| Horst | A elongated uplifted block bounded by faults along its length |
| Hurricane | Massive revolving storm that produces winds over 120 km/hr and heavy rainfall |
| Hydrological cycle | The evaporation and condensation of water on a world scale |
| Hydrosphere | All waters (liquid and solid) on the surface of the earth oceans, lakes, rivers, aquifers, and ice |
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| Ice Age | Long period of colder climate when snow and ice covered large areas of the Earth |
| Ice field | Extensive area of interconnected glaciers in a mountain region, or of pack ice at sea |
| Ice sheet | Large expanse of snow and ice that covers a land mass, for example Antarctica |
| Ice shelf | Sheet of floating ice |
| Icecap | Large expanse of ice and snow, covering the summit area of a mountain, an island, or a flat land mass |
| Icefall | Section of a glacier where an abrupt change of gradient causes the ice to go down a steep slope causing intense crevassing |
| Igneous | Rock formed by the molten material from volcanoes. There are two types intrusive molten material within the earth’s crust forced into older rock or between layers of older rock (e.g. granite); and extrusive molten material that has been ejected onto the earth’s surface (e.g. lava, volcanic ash) |
| Inertia | The property of a body to oppose changes in its motion |
| Insolation | Amount of energy received from the sun |
| Interglaciation | Long period of time (10,000+ years) characterized by climatic conditions associated with minimum glacial extent |
| Interstade | Short period of time (less than 10,000 years) characterized by climatic conditions associated with minimum glacial extent |
| Intertidal zone | The area of shoreline covered by seawater at high tide and exposed to the air at low tide |
| Ionosphere | A region of the Earth’s atmosphere beginning at an altitude of about 75 km and extending to an indefinite height. This is where free electrons and ions (which affect radio waves) are produced by solar radiation |
| Irradiance | The flow of radiant energy per unit area (expressed in watts/meter2) |
| Irrigation withdrawals | The removal of water from rivers, lakes, and wells for the purpose of agriculture |
| Isostasy | A state of balance of the Earth’s land masses whereby some areas are rising and others sinking as material is eroded and deposited |
| Isotope | One of or set of chemically identical atoms which have the same atomic number but different mass numbers |
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| Jet stream | Strong current of air blowing through the atmosphere at a high altitude, generally from west to east and at speeds up to 300 km/hr |
| Joint | Geological vertical or near-vertical crack in rock |
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| Kyoto target | A set of emissions requirements for signatory nations to meet. The requirements are generally based on the level of emissions each nation had in 1990 |
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| Latitude | Angular distance north or south of the Equator, measured at an angle from the Earth’s center. Lines of latitude are parallel to the Equator that is 0˚ Latitude |
| Laurasia | Northern part of the ancient super-continent of Pangaea. It consisted of North America, Europe, and Asia |
| Limestone | Rock formed on the bed of a warm sea by accumulation of dead sea creatures |
| Lithosphere | Outer rigid shell of the earth which forms its surface. It extends down to depths of about 40 km and ‘floats’ on the denser asthenosphere below it |
| Loess | Wind-blown soil consisting of very fine particles of clay |
| Lyme Disease | An acute inflammatory disorder spread by ticks found in heavily wooded areas in summer |
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| Magma | Molten rock, including dissolved water and gases formed at a depth and remaining or moving within the crust. If it flows onto the surface it is called lava |
| Mangroves | Low trees noted for their dense, interlacing above ground roots; found in marshes and tidal shores |
| Mantle | The part of the earth between the lithosphere and the core, (from 40 km to 2900 km). The upper part of the mantle is the asthenosphere |
| MBP | Millions of years before the present |
| Mean | The average of a set of values |
| Meander | Bend or curve in the course of a river |
| Meltwater | Water created by the melting of snow and ice |
| Metamorphic rocks | Sedimentary and igneous rock changed by heat or pressure to form a new type of rock. For example, limestone under heat and pressure becomes marble |
| Meteorologist | A scientist who studies and reports on the changing conditions of the earth’s atmosphere |
| Micro-organism | An organism of microscopic or submicroscopic size, especially a bacterium or protozoan |
| Milankovitch Cycles | The collective effect of changes in the Earth’s movements upon its climate |
| Mitigation | The influencing effect of a factor or force on a given situation |
| Monsoon | A seasonal wind, usually bringing heavy rainfall to regions in southern and southeast Asia |
| Moraine | A distinct accumulation of unsorted rock debris deposited directly from a melting glacier |
| MY | Million years |
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| NAO | North Atlantic Oscillation. The opposing variations of atmospheric pressure near Iceland (low) and the Azores (high). It is the dominant mode of climate variability in the North Atlantic |
| Net Solar Radiation | A measure of the incoming radiation incident on the earth’s surface minus the outgoing energy radiated by the earth itself |
| Niagara Escarpment | Steep cliff (scarp) which runs north from Queenston to Tobermory in Ontario |
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| Obliquity | Angle of the Earth’s rotational axis from the plane of its orbit around the sun |
| Ocean basins | Depressions on the surface of the lithosphere occupied by an ocean |
| Orogenesis | Process of mountain formation, especially by volcanism or by folding and faulting of the earth’s crust |
| Orographic uplift | Movement upwards of air masses encountering mountain ranges |
| Orography | A recording of distance and elevation over land surface with the information used to create topographic maps |
| Outlier | Mass of newer rocks surrounded by older rocks |
| Outwash plain | An area built up by the sand and gravel brought down by streams flowing from a glacier or an ice sheet |
| Oxidation | Chemical reaction of oxygen with other elements |
| Ozone layer | Protective layer of ozone surrounding earth |
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| Paleoclimatology | Study of prehistoric climates |
| Paleogeology | Study of ancient rocks |
| Paleoproxy data | Information about ancient climate obtained through the examination of tree rings, corals, etc. |
| Pangea | Name given to vast land mass (a ‘supercontinent’) which, 200 millions of years ago, was the only land on the Earth |
| Peneplain | An extensive, nearly flat area of the earth’s surface, resulting from erosional processes over a long time |
| Perihelion | Phase in its orbit when the Earth is closest to the sun |
| Permafrost | Permanently frozen soil, subsoil or other ground deposit |
| Phenology | The recording and study of periodic biologic phenomena (e.g. plant flowering times) in relation to climate, particularly seasonal changes |
| Photodissociated | Molecules split apart by light (e.g. ozone is photodissociated by sunlight) |
| Photorespiration | The oxidation of carbohydrates in plants with the release of carbon dioxide, energy and water during photosynthesis |
| Photosynthesis | Process by which plants use the light energy, carbon dioxide, and water to make oxygen and glucose (a simple sugar) |
| Photovoltaic systems | The use of photovoltaic cells to convert sunlight directly into electricity |
| Planktic and benthic foraminifera | These are single-celled organisms that construct shells. The planktic foraminifera float freely while the benthic foraminifera live in or on sea floor sediments |
| Plate tectonics | The interpretation of the earth’s major structures and processes in terms of the movements of the underlying plates of lithosphere acting as rigid slabs ‘floating’ on the asthenoshphere (mantle) below |
| Pleistocene | Geological epoch that refers to the last two million years, the time of the last great ice ages |
| Plucking | Process of glacial erosion by which blocks of rock are loosened, detached, and borne away from bedrock as water freezes in fissures |
| Plunge pool | Pool at the base of a waterfall formed by the erosive action of the falling water and the rocks carried by that water |
| Polar climate | Climate at latitudes greater than 66o characterized by an annual average temperature of under 10oC |
| Polar Jet Stream | Upper air (about 12 km altitude) winds found between 40o and 60o latitude at speeds usually greater than 90km/hr (and up to 400 km/hr) |
| ppm | Parts per million |
| Precession | Earth’s slow wobble as it spins on axis |
| Precipitation | Products of condensation in the atmosphere, including rain, sleet, snow, hail, dew, and hoar frost |
| Progradation | The building of strata from sediment in a seaward direction due to rising sea levels |
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| Quadruped | A four footed animal. i,e, quadrupedal |
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| Radiation | The emission of energy in the form of waves or rays |
| Radiative forcing | A change in the radiation balance due to changes in solar radiation or in the environment. A positive forcing tends to warm the atmosphere. It may be expressed in C˚/wm2 |
| Rapids | Small waterfalls and turbulent water along a stretch of river |
| Refreezing | The melting and subsequent refreezing that takes place between two blocks of ice as pressure is applied then released |
| Relief (Orographic) Precipitation | Precipitation caused when warm, moist air follows the higher contours of a landform. Air cools as it rises and water vapour condenses and drops |
| Riparian | A term used in describing the natural banks of a water course |
| Rodinia | Name given to the first super continent in the Late Proterozoic era. It broke into four major areas Gondwana, Laurentia, Siberia (just south of the equator) and Baltica |
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| Salinization | The accumulation of natural salts in a soil, often the result of irrigation in the water table |
| Scenario | A hypothetical or predicted sequence of events |
| Sea-ice dynamics | Forces affecting the motion of pack ice, mainly wind and water motion |
| Sedimentary rock | Rock made of layers of eroded sediment put under tremendous pressure at the bottom of seas and oceans |
| Semi-permeable membranes (selectively permeable membrane) | A membrane which will allow only certain molecules or ions to pass through it |
| Silviculture | The care and cultivation of forests |
| Solar radiation | Energy from the sun traveling in light rays |
| SST | Sea surface temperature |
| Stade | Short period of time (less than 10,000 years) characterized by climatic conditions associated with maximum glacial extent |
| Stratified drift | Sediments deposited by glacial meltwater that are sorted and layered. A major subdivision of glacial drift that includes rivers, lakes, and marine deposits |
| Stratosphere | The zone of the atmosphere which lies above the troposphere (from 10-15 km to about 50 km up) |
| Stream capacity | The maximum amount of sediment a stream can carry with a given discharge |
| Striation | The process in which scratches and grooves are made by glacial ice scraping over rocks. It is the rock particles carried by the ice that cause the scratches. The direction of the scratches (striae) indicated the direction of the glacier’s advance |
| Subduction | The process of one lithospheric plate descending under an adjacent plate |
| Sublimation | The direct change of a material from a solid state to a gas state without turning to liquid in between |
| Sustainable | A practice capable of being continued indefinitely |
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| Tectonic displacements | The vertical or horizontal shifting of land masses due to forces beneath the Earth’s crust |
| Temperate climate | Climate typical of the mid-latitudes, with neither exceptionally high (tropical) nor low (polar) temperatures and precipitation. May be either wet (maritime) or dry (continental) |
| Terrestrial radiation | The emission of heat energy from the Earth’s surface and atmosphere into space |
| Thermohaline | The term used in relating to the density of sea water which is determined by temperature and salt content |
| Thermohaline circulation | The movement of ocean water due to differences in density |
| Tidewater glacier | Glacier which terminates in ocean water. The changing sea levels due to tides may accelerate the calving of glaciers |
| Till (or glacial till) | Rock, sand, and fine-grained clay deposited by glaciers |
| Tillage | The cultivation of land for crops |
| Tillite | Sedimentary rock composed of till. Generally considered evidence of pre-Pleistocene glaciations, but identification (compared to landslide debris, for example) is difficult |
| Tornado | Violent, localized storm with powerful funnel clouds that create much damage |
| Tropical | Low latitude (less than 20o latitude) areas characterized by high temperatures and high precipitation. At high elevations, however, tropical mountains may be both cold and relatively dry |
| Tropopause | The boundary between the troposphere and stratosphere varying in altitude from approximately 8 km at the poles to 18 km at the poles |
| Troposphere | Lowest part of the atmosphere, from the ground or ocean surface to about 10-15 km |
| Trough (or “U-shaped valley”) | Steep-walled, (though rarely vertical), and broad-floored. Its presence indicates former mountain glaciation |
| Typhoon | A tropical storm occurring in the western Pacific or Indian Ocean. It is the same as a hurricane |
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| Ultraviolet | Short wavelength beyond the visible spectrum at the violet end of the spectrum |
| UV radiation (A, B, and C) | Radiation with wavelengths between those of visible light and those with x-rays. UVA (380-315 nm) are long wave; UVB (315-280 nm) are medium wave; and UVC (280-10 nm) are short wave |
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| Variables | A measurable factor, characteristic, or attribute of a system |
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| Weather | Meteorological conditions experienced over a short period of time |
| Weathering | Disintegration of rocks caused by physical and chemical forces and processes |
| Westerlies | Prevailing planetary winds in temperate latitudes |
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| YBP | Years before present |