• Greenhouse Gases - Greenhouse gases (GHGs) are gaseous components of the atmosphere that contribute to the "greenhouse effect".
• Climate Change Glossary - Glossary of climate change terms.
  
  

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Glossary of Climate Change

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* Anthropogenic: literally, man-made

* Anthropogenic climate change: climate change with the presumption of human influence, usually warming

* Attribution: the study of what has caused climate change

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* Black carbon - an aerosol

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* Carbon sequestration - Proposals for removing CO2 from the atmosphere, or for preventing CO2 from fossil fuel use ever being released.

* Climate commitment studies - How much future warming is "committed", even if greenhouse gas levels do not rise.

* Climate change - changes of climate in general, usually with no presumption of human influence. Note, however, that there is one important exception to this: the UNFCCC defines "climate change" as anthropogenic.

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* Earth's atmosphere -a layer of gases surrounding the planet Earth and retained by the Earth's gravity. It contains roughly 78% nitrogen and 21% oxygen, trace amounts of other gases, and water vapor. This mixture of gases is commonly known as air. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation and reducing temperature extremes between day and night.

* El Niño/ENSO -El Niño-Southern Oscillation (ENSO) is a global coupled ocean-atmosphere phenomenon. The Pacific ocean signatures, El Niño and La Niña (also written in English as El Nino and La Nina) are major temperature fluctuations in surface waters of the tropical Eastern Pacific Ocean. The names, from the Spanish for "the little boy" and "the little girl", refer to the Christ child, because the phenomenon is usually noticed around Christmas time in the Pacific Ocean off the west coast of South America. Their effect on climate in the southern hemisphere is profound. While ENSO is a global and natural part of the Earth's climate, whether its intensity or frequency may change as a result of global warming is an important concern.

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* Fossil fuel - Fossil fuels are hydrocarbons formed from the remains of dead plants and animals. The theory that hydrocarbons were formed from these remains was first introduced by Mikhail Lomonosov in 1757. In common dialogue, the term fossil fuel also includes hydrocarbon-containing natural resources that are not derived from animal or plant sources. These are sometimes known instead as mineral fuels. The utilization of fossil fuels has enabled large-scale industrial development and largely supplanted water-driven mills, as well as the combustion of wood or peat for heat.

* Freon - The haloalkane (also known as halogenoalkanes) are a group of chemical compounds, consisting of alkanes, such as methane or ethane, with one or more halogens linked, such as chlorine or fluorine, making them a type of organic halide. They are known under many chemical and commercial names. As fire extinguishants, propellants and solvents they have or had wide use. Some haloalkanes have negative effects on the environment such as ozone depletion. The most widely known family within this group are the chlorofluorocarbons (CFCs).

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* Global cooling - Global cooling in general can refer to a cooling of the earth; more specifically, it is a theory positing an overall cooling of the Earth and perhaps the commencement of glaciation. This theory gained temporary popular attention due to press reporting following a better understanding of ice age cycles and a temporary downward trend of temperatures in the 1970s. The theory never had strong scientific support. At present, the Earth is not cooling, but rather to be in a period of global warming mostly attributed to human activity.

* Global climate model, also General Circulation Model or GCM - a computer model of the world's climate system, including the atmosphere and oceans.

* Global warming — usually: the warming trend over the past century or so; also: any period in which the temperature of the earth's atmosphere increases; also the theory of such changes.

* Global warming controversy — socio-political issues surrounding the theory of global warming.

* Global warming period - any period in which the temperature of the earth's atmosphere increases

* Global warming potential - Global warming potential (GWP) is a measure of how much a given mass of greenhouse gas is estimated to contribute to global warming. It is a relative scale which compares the gas in question to that of the same mass of carbon dioxide (whose GWP is by definition 1). A GWP is calculated over a specific time interval and the value of this must be stated whenever a GWP is quoted or else the value is meaningless.

* Greenhouse effect - The greenhouse effect, first discovered by Joseph Fourier in 1824, and first investigated quantitatively by Svante Arrhenius in 1896, is the process in which the absorption of infrared radiation by an atmosphere warms a planet. Without these greenhouse gases, the Earth's surface would be up to 30 °C cooler. The name comes from an incorrect analogy with the way in which greenhouses are heated by the sun in order to facilitate plant growth. In addition to the Earth, Mars, Venus and other celestial bodies with atmospheres (such as Titan) have greenhouse effects. In common parlance, the term "greenhouse effect" may be used to refer either to the natural greenhouse effect, due to naturally occuring greenhouse gases, or to the enhanced (anthropogenic) greenhouse effect, which results from gases emitted as a result of human activities (see also global warming, scientific opinion on climate change and attribution of recent climate change).

* Greenhouse gases - are gaseous components of the atmosphere that contribute to the "greenhouse effect". Although uncertainty exists about exactly how earth's climate responds to these gases, global temperatures are rising. Some greenhouse gases occur naturally in the atmosphere, while others result from human activities. Naturally occuring greenhouse gases include water vapour, carbon dioxide, methane, nitrous oxide, and ozone. Certain human activities, however, add to the levels of most of these naturally occurring gases.

* Gulf Stream - The Gulf Stream, together with its northern extension, the North Atlantic Drift, is a powerful, warm, and swift Atlantic ocean current that originates in the Gulf of Mexico, exits through the Strait of Florida, and follows the eastern coastlines of the United States and Newfoundland before crossing the Atlantic Ocean. At about 30°W, 40°N, it splits in two, with the northern stream crossing to northern Europe and the southern stream recirculating off West Africa. The Gulf Stream influences the climate of the east coast of North America from Florida to Newfoundland, and the west coast of Europe.

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* Holocene - The Holocene epoch is a geological period that extends from the present day to back about 10,000 radiocarbon years, approximately 11,430 ± 130 calendar years BP (between 9560 and 9300 BC). Human civilization dates entirely to the Holocene.

* Holocene Climatic Optimum - The Holocene Climate Optimum was a warm period during roughly the interval 9,000 to 5,000 years B.P.. This event has also been known by many other names, including: Hypisthermal, Altithermal, Climatic Optimum, Holocene Optimum, Holocene Thermal Maximum, and Holocene Megathermal. This warm period was followed by a gradual decline until about 2,000 years ago.

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* Ice age - An ice age is a period of long-term downturn in the temperature of Earth's climate, resulting in an expansion of the continental ice sheets, polar ice sheets and mountain glaciers ("glaciation"). Glaciologically, ice age is often used to mean a period of ice sheets in the northern and southern hemispheres.

* Ice core - An ice core is a core sample from the accumulation of snow and ice over many years that have recrystallized and have trapped air bubbles from previous time periods. The composition of these ice cores, especially the presence of hydrogen and oxygen isotopes, provides a picture of the climate at the time.

* Insolation - amount of solar radiation reaching the surface of the Earth.

* Instrumental temperature record - quasi-global since 1850

* Interdecadal Pacific Oscillation (IPO) - a cycle of 15-30 years between warm or cool waters in the north and south Pacific

* Intergovernmental Panel on Climate Change - The Intergovernmental Panel on Climate Change (IPCC) was established in 1988 by two United Nations organizations, the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) to assess the "risk of human-induced climate change". The Panel is open to all members of the WMO and UNEP.

* Intertropical convergence zone - belt of low pressure caused by the convergence of warm, moist air from the latitudes above and below the equator.

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* Kyoto Protocol - an amendment to the international treaty on climate change, assigning mandatory targets for the reduction of greenhouse gas emissions to signatory nations.

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* Little Ice Age - The Little Ice Age (LIA) was a period of cooling occuring after a warmer era known as the Medieval climate optimum. Climatologists and historians find it difficult to agree on either the start or end dates of this period. Some confine the Little Ice Age to 1550-1850, lasting approximately from the 14th to the mid-19th centuries while others prefer a span from the 13th to 17th centuries. It is generally agreed that there were three minima, beginning about 1650, about 1770, and 1850, each separated by slight warming intervals

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* Mauna Loa: home to the longest instrumental CO2 record

* Medieval climate optimum: warm period from about the 10th century to about the 14th century

* Meteorology: some of the basic science underlying climate

* Methane: a greenhouse gas

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* US National Assessment on Climate Change - The National Assessment on Climate Change (NACC) was a massive multidisciplinary effort to study and portray in regional detail the potential effects of human-induced global warming on the United States. The project was articulated into some 20 regional studies - each involving dozens of scientific and academic experts as well as representatives of industry and environmental groups.

* North Atlantic Deep Water: one of the water masses of the ocean. It has been shown that the North Atlantic Deep Water has shut down in the past (such as during the Younger Dryas), and that this decreases the strength of the Gulf Stream and the North Atlantic drift, in turn cooling the climate of northwestern Europe. There is concern that global warming might cause this to happen again.

* North Atlantic oscillation: an atmospheric climate mode

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* Ozone depletion: not strongly connected to climate change. The term ozone depletion is used to describe two distinct but related observations: a slow, steady decline, of about 3% per decade, in the total amount of ozone in the earth's stratosphere during the past twenty years and a much larger, but seasonal, decrease in stratospheric ozone over the earth's polar regions during the same period.

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* Pacific decadal oscillation (PDO) - a 23-year pattern of warm or cool water in the north Pacific

* Phenology - the study of the times of recurring natural phenomena. The word is derived from the Greek Phainomai - to appear, come into view, and indicates that phenology has been principally concerned with the dates of first occurrence of natural events in their annual cycle. Examples include the date of emergence of leaves and flowers, the first flight of butterflies and the first appearance of migratory birds, the date of leaf colouring and fall in deciduous trees, the dates of egg-laying of birds and amphibia, the timing of the developmental cycles of honeybee colonies. Because many such phenomena are very sensitive to small variations in climate, especially to temperature, phenological records can be a useful proxy for temperature in the study of climate change.

* Proxy - a variable that can be related to one of interest (e.g. tree rings can be proxies for temperature variations)

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* radiative forcing - As a general concept, the term radiative forcing in climate science means any change in the radiation (heat) entering or leaving the climate system. It can be due to changes in sunlight arriving, or to differing amounts of radiatively active gases.

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* Satellite temperature measurements - Satellites have been sensing the temperature of the troposphere since 1979; the usable balloon (radiosonde) record begins in 1958.

* Scientific opinion on climate change - Various prominent bodies have commented on global warming, most notably the Intergovernmental Panel on Climate Change (IPCC). National and international scientific groups have issued statements both detailing and summarizing the current state of scientific knowledge on the earth's climate.

* Sea level rise - Sea level rise is an increase in sea level. Multiple complex factors may influence such changes. The sea level has risen more than 120 metres since the peak of the last ice age about 18,000 years ago. The bulk of that occurred before 6,000 years ago. From 3,000 years ago to the start of the 19th century sea level was almost constant, rising at 0.1 to 0.2 mm/yr; since 1900 the level has risen at 1 to 3 mm/yr; since 1992 satellite altimetry from TOPEX/Poseidon indicates a rate of about 3 mm/yr . This change may be the first sign of the effect of global warming on sea level.Warming is predicted to cause significant rises in sea level over the course of the twenty-first century.

* Solar variation - fluctuations in the amount of energy emitted by the Sun. Small variations have been measured from satellites during recent decades. Of interest to climate scientists is whether these variations have a significant effect on the temperature of Earth's atmosphere. A 2006 study and review of existing literature, published in Nature, determined that there has been no net increase in brightness since the mid 1970s, and that changes in solar output within the past 400 years are unlikely to have played a major part in global warming.

* Sunspot - A sunspot is a region on the Sun's surface (photosphere) that is marked by a lower temperature than its surroundings and intense magnetic activity, which inhibits convection, forming areas of low surface temperature. Although they are blindingly bright, at temperatures of roughly 4000-4500 K, the contrast with the surrounding material at some 5700 K leaves them clearly visible as dark spots.

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* Urban heat island - An urban heat island (UHI) is a metropolitan area which is significantly warmer than its surroundings. As population centers grow in size from village to town to city, they tend to have a corresponding increase in average temperature, which is more often welcome in winter months than in summertime. The EPA says: "On hot summer days, urban air can be 2-10°F [2-6°C] hotter than the surrounding countryside. Not to be confused with global warming, scientists call this phenomenon the 'urban heat island effect'"

* United Kingdom Climate Change Programme - The United Kingdom's Climate Change Programme was launched in November 2000 by the British government in response to its commitment agreed at the 1992 United Nations Conference on Environment and Development (UNCED). The aims of the programme is not only to cut all greenhouse gas emissions by the agreed 12.5% from 1990 levels in the period 2008 to 2012 (the international commitment), but to go beyond this by cutting carbon dioxide emissions by 20% from 1990 levels by 2010.

* United Nations Framework Convention on Climate Change - The United Nations Framework Convention on Climate Change (UNFCCC or FCCC) is an international environmental treaty produced at the United Nations Conference on Environment and Development (UNCED), informally known as the Earth Summit, held in Rio de Janeiro in 1992. The treaty aimed at reducing emissions of greenhouse gas in order to

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* World climate research programme - The World climate resarch programme (WCRP) was established in 1980, under the joint sponsorship of International Council for Science and the World Meteorological Organization and also been sponsored by the Intergovernmental Oceanographic Commission of UNESCO since 1993. The objectives of the programme are to develop the fundamental scientific understanding of the physical climate system and climate processes needed to determine to what extent climate can be predicted and the extent of human influence on climate. The programme encompasses studies of the global atmosphere, oceans, sea ice and land ice, and the land surface which together constitute the Earth's physical climate system.