Climate Dictionary

Stratospheric Ozone

PSCs

Tropospheric Ozone

Images

CLIMATE CHANGE DEFINITIONS

Dictionaries

Here is a link to a page of meteorological dictionaries. If you want just one source, the Weather Channel's dictionary is here (Thanks to them for providing the dictionary and most of the definitions below).

The European Environment Agency has an online dictionary which explains most terms used in climate and environmental change.

Climate Change Buzz Words

Acid rain: rain containing acids that form in the atmosphere when industrial gas emissions (especially sulfur dioxide and nitrogen oxide) combine with water.

Aerosol: a cloud of solid or liquid particles in a gas; a dispenser that forces a liquid out as a fine spray when a button is pressed.

Anthropogenic: Anthropogenic climate change is change caused by human activity.

Carbon dioxide: Gas naturally produced by animals during respiration and through decay of biomass, and used by plants during photosynthesis. Although it only constitutes 0.04 percent of the atmosphere, it is one of the most important greenhouse gases. The combustion of fossil fuels is increasing carbon dioxide concentrations in the atmosphere, which is believed to be contributing to global warming.

Carbon sequestration: The uptake and storage of carbon. Trees and plants, for example, absorb carbon dioxide, release the oxygen and store the carbon.

Climate: The historical record and description of average daily and seasonal weather events that help describe a region. Statistics are generally drawn over several decades.

Climate change: Climate change refers to any change in climate over time, whether due to natural variability or as a result of human activity. This usage differs from that in the United Nations Framework Convention on Climate Change (UNFCCC), which defines 'climate change' 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 comparable time periods.'

Global warming: Changes in the surface-air temperature, referred to as the global temperature, brought about by the greenhouse effect which is induced by emission of greenhouse gases into the air.

Greenhouse effect: The overall warming of the earth's lower atmosphere primarily due to carbon dioxide and water vapor. These gases permit the sun's rays to heat the earth, but then restrict some heat-energy from escaping back into space.

Intergovernmental Panel for Climate Change (IPCC): Widely regarded as the most authoritative international voice on the science and impacts of climate change. Established by governments under the auspices of the World Meteorological Organisation and UN Environment Programme (UNEP) in 1988, the IPCC produces five-yearly reports assessing the state of knowledge on climate change which represent the international consensus among the more than 2 000 experts involved. It has also published reports on specific issues, such as sinks.

Kyoto Protocol: The Kyoto Protocol was adopted at the Third Session of the Conference of the Parties (COP) to the UN Framework Convention on Climate Change (UNFCCC) in 1997 in Kyoto, Japan. It contains legally binding commitments to reduce anthropogenic emissions of greenhouse gases (CO2, CH4, N2O, HFCs, PFCs, and SF6) by at least 5 percent below 1990 levels in the commitment period 2008 to 2012.

Methane: Colorless gas given off by rotting materials. The main constituent of natural gas.

Oxidant: a substance that oxidizes another substance.

Oxidize: add oxygen to, or combine with oxygen; enter into a combination with oxygen or become converted into an oxide.

Ozone: Ozone (O₃) is a very "active" form of oxygen which reacts rapidly and strongly with living tissues, plant-derived fabrics, dyes, rubber and many other man-made materials. A colorless gas, it has no odor except near high energy sources such as strong electrical arcs, sparks or close to a lightning strike. Ozone is the major photochemical oxidant and represents about 90 percent of all oxidants found in the air. Ozone is a highly reactive gas that affects the respiratory system by severely irritating the mucous membranes of the nose and throat. Since 90 percent of the ozone breathed into the lungs is never exhaled, ozone molecules react with sensitive lung tissue to cause several health consequences. (Thanks to DNR, WI).

Ozone layer (stratospheric ozone layer): The fragile shield of ozone is being damaged by chemicals released on earth. The main chemicals that are depleting stratospheric ozone are chlorofluorocarbons which are used in refrigerators, aerosols, and as cleaners in many industries, and halons, which are used in fire extinguishers. The damage is caused when these chemicals release highly reactive forms of chlorine and bromine. Over the past 30 years ozone levels over parts of Antarctica have dropped by almost 40 % during some months and a 'hole' in ozone concentrations is clearly visible in satellite observations.

Ozonesonde: Lightweight ozone detector designed to be flown on a small weather balloon; instrument carried aloft by balloon to measure the vertical variations of ozone concentration in the atmosphere.

Photochemical Reaction: A term referring to chemical reactions brought about by the light energy of the sun. The reaction of nitrogen oxides with hydrocarbons in the presence of sunlight to form ozone is an example of a photochemical reaction.

Polar stratospheric clouds (PSCs), also called pearl clouds: These are high altitude clouds (at about 18 kilometers or 60,000 feet) that exist only at the poles. They play a unique role in atmospheric ozone loss. The visually beautiful, opalescent clouds (which look like mother of pearl) form only at the cold temperatures found at the poles. These clouds help trigger the conversion of chlorine from relatively non-reactive forms to a form (chlorine monoxide, or ClO) that, in combination with sunlight, destroys ozone.

Polar Vortex: This is a phenomenon that occurs during the polar winter in which stratospheric air moves in a circular motion, with an area of relatively still air in its centre. The temperature in the vortex is approximately -130 degrees F (-80 degrees C), which assists in the formation of polar stratospheric clouds. Though usually more prolonged and colder over Antarctica, the Arctic polar vortex does form to a degree, and when the temperatures there are coldest and the vortex persists, Arctic stratospheric ozone destruction on Arctic polar stratospheric clouds has also been observed.

Radiosonde: An instrument attached to a weather balloon used to measure pressure, temperature, humidity, and winds aloft. Observations are made when the radiosonde is aloft and emits radio signals as it ascends. May be referred to as a RAOB, an acronym for RAdiosonde OBservation.

Sink (as in 'carbon sink'): Forests and other ecosystems that absorb carbon, thereby removing it from the atmosphere and offsetting CO2 emissions. The Kyoto Protocol allows certain human-induced sinks activities undertaken since 1990 to be counted towards emission targets.

Smog: Air pollution by a mixture of smoke and fog; A mixture of air pollutants, principally ground-level ozone, produced by chemical reactions involving smog-forming chemicals; A concentration of air pollutants occurring under particular meteorological conditions, generally of photo-chemical origin. Smog occurs when high concentrations of moisture is combined with smoke (often containing oxides of sulfur and nitrogen) in the presence of high temperatures or thermal inversions and the absence of wind. These conditions cause polluted air to stagnate over industrial areas and can create a respiratory health hazard.

Stratosphere: The layer of the atmosphere located between the troposphere and the mesosphere, characterized by a slight temperature increase and absence of clouds. It extends between 11 and 31 miles (17 to 50 kilometers) above the earth's surface. It is the location of the earth's ozone layer.

Sulfur Dioxide: Heavy, pungent, colourless gas formed primarily by the combustion of fossil fuels. It is harmful to human beings and vegetation, and contributes to the acidity in precipitation.

Troposphere: The lowest layer of the atmosphere located between the earth's surface to approximately 11 miles (17 kilometers) into the atmosphere. Characterized by clouds and weather, temperature generally decreases with increasing altitude.

Volatile Organic Compound (VOC):  Hydrocarbons (volatile organic compounds, or VOC's) and nitrogen oxides (NO_x), the ozone precursors, chemically react in sunlight to form ozone. Sources of VOC's include: automobile exhaust; gasoline and oil storage and transfer; industrial use of paint solvents, degreasing agents, cleaning fluids, and ink solvents; incompletely burned coal or wood. Plants, to a lesser degree, give off similar substances, such as terpenes from pine trees.