Climate change glossary

Afforestation:  Establishing and growing forests to remove greenhouse gases from the atmosphere on land which has not been forested in recent history.

Atmosphere: The envelope of gases surrounding the Earth and other planets. Many of these gases are involved in chemical cycles such as the nitrogen and carbon cycles that sustain life on Earth and shape the planet's habitability. Nitrogen, oxygen, and water vapour make up more than 99% of the atmosphere, while so-called trace gases including carbon dioxide, methane and other "greenhouse" gases constitute the remainder.

Atmospheric pressure: The pressure of atmospheric gases on the surface of the planet. High atmospheric pressure generally leads to stable weather conditions, whereas low atmospheric pressure leads to storms such as cyclones.

Business-as-usual: The scenario for future world patterns or energy consumption and greenhouse gas emissions which assumes that there will be no major changes in attitudes and priorities.

Cap and trade:  The Cap and Trade system involves trading of emission allowances, where the total allowance is strictly limited or 'capped'. A regulatory authority established the cap which is usually considerably lower than the historic level of emissions.

Carbon dioxide (CO2): One of the major greenhouse gases. Human-generated carbon dioxide is caused mainly by the burning of fossil fuels.

Carbon sink: Repository for carbon dioxide (CO2) removed from the atmosphere. Oceans appear to be major sinks for storage of atmospheric

Carbon tax: A policy that would tax fossil fuels according to the amount of carbon they contained. This would reduce the demand for fossil fuels in general and cause realignment away from coal to less polluting natural gas, or renewable sources of energy.

CFC’s (Chlorofluorocarbons): A group of chemicals containing chlorine (Cl), fluorine (F) and carbon (C). These synthetic compounds were used extensively for refrigeration and aerosol sprays until it was realised that they destroy ozone (they are also very powerful greenhouse gases) and have a very long lifetime once in the atmosphere (more than 100 years). The Montreal Protocol agreement of 1987 has resulted in the scaling down of CFC production and use in industrialised countries.

Clean Development Mechanism: A mechanism of the Kyoto Protocol for reducing emissions through implementing projects in developing countries. The CDM aims to meet two main objectives, 1) to address the sustainable development needs of developing countries and 2), to increase the opportunities available to reduce emissions.

Climate change:  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 over comparable time periods.

Commitment period:  The first commitment period of the Kyoto Protocol, which runs from 2008 to 2012.  It is planned to be followed by subsequent commitment periods.

Conference of Parties (COP):  The COP is the overall managing body of the United Nations Framework Convention on Climate Change.  The COP consists of more than 170 nations that ratified or acceded to the Framework Convention on Climate Change.  It is responsible for promoting and reviewing the implementation of the Convention.

Deforestation: Cutting down forests; one of the causes of the enhanced greenhouse effect, not only when the wood is burned or decomposes, releasing carbon dioxide, but also because trees previously took carbon dioxide from the atmosphere in the process of photosynthesis.

Emissions Trading: A market mechanism that allows emitters (countries, companies or facilities) to buy emissions from or sell emissions to other emitters.

Environmentally-sound: The maintenance of a healthy environment and the protection of life-sustaining ecological processes. It is based on thorough knowledge and requires or will result in products, manufacturing processes, developments, etc. which are in harmony with essential ecological processes and human health.

Eutrophication: The occurrence of high nutrient levels in freshwater and marine ecosystems, usually resulting in excessive plant growth and the death of animal and some plant life due to oxygen deprivation.

Flooding: The inundation of normally dry land by water. Flooding causes millions of dollars'-worth of property damage and takes hundreds of lives each year. Climate change through the increased melting of glaciers and ice sheets, and the subsequent rise in sea level, has the potential to increase the frequency and extent of coastal flooding.

Fossil fuels: Fuels such as coal, oil and gas made by decomposition of ancient animal and plant remains which give of carbon dioxide when burned.

Global warming: The idea that increased greenhouse gases cause the Earth’s temperature to rise globally.  (See climate change).

Greenhouse effect: The cause of global warming. Incoming solar radiation is transmitted by the atmosphere to the Earth’s surface, which it warms. The energy is retransmitted as thermal radiation, but some of it is absorbed by molecules of greenhouse gases instead of being retransmitted out to space, causing the temperature of the atmosphere to rise.  The ‘natural’ greenhouse effect is due to the greenhouse gases present for natural reasons. The ‘enhanced’ greenhouse effect is the added effect caused by the greenhouse gases present in the atmosphere due to human activities, such as burning of fossil fuels and deforestation.

Greenhouse gas emissions: The release of greenhouse gases into the atmosphere, causing climate change.

Greenhouse gases: Molecules in the Earth’s atmosphere such a carbon dioxide (CO2), methane (CH4) and CFCs which warm the atmosphere because they absorb some of the thermal radiation emitted from the earth's surface.

IPCC: Intergovernmental Panel on Climate Change formed by the World Meteorological Organisation (WMO) and the United Nations Environment Programme (UNEP) in 1988. The IPCC represents the work of over 2,000 scientists. The IPCC doesn’t conduct original research but its reports play an important role in the creation of climate change policies worldwide. The IPCC played a role in establishing the UNFCCC or the Convention. 

Joint Implementation:  A mechanism developed under the Kyoto Protocol designed to assist developed countries in meeting their emission reduction targets through joint projects with other developed countries.

Kyoto Protocol: An international and legally binding agreement to reduce greenhouse gas emissions worldwide, entered into force in 2005. 

Methane: A simple hydrocarbon gas (CH4) produced during the decomposition of organic material under anaerobic conditions. It is the main constituent of natural gas and therefore and important fuel.

Monsoon: Particular seasonal weather patterns in sub-tropical regions which are connected with particular periods of heavy rainfall.

Ozone: An unstable and chemically-reactive gas containing three oxygen atoms, formed at high altitudes by the action of sunlight on molecular oxygen. Present at low concentration in the stratosphere, ozone absorbs ultraviolet radiation from the sun and reduces the amount of this damaging radiation that reaches the Earth's surface. Ozone is also formed at ground level - by the interaction of sunlight with exhaust gases from automobiles and industry, and by the action of sunlight on nitrogen oxides and hydrocarbons-where it is a primary component of smog that aggravates breathing problems and damages plants.

Ozone hole: A popular name given to a phenomenon discovered in 1987, when scientists measured unexpectedly low ozone concentrations in the stratosphere above the South Pole during the Antarctic spring. It is now generally accepted that the loss of stratospheric ozone is caused by chemical reactions initiated by chlorofluorocarbons.

Petrochemicals: Chemicals derived from oil and natural gas.  Petrochemicals play a very important role in modern society, but they also create pollution problems. Plastics are a major component of solid waste, for example, fertilisers contribute to eutrophication of lakes and rivers and pesticide residues in food and water present health problems.

Petroleum: A mixture of naturally occurring hydrocarbons that may exist in a solid (e.g. bitumen), liquid (e.g. crude oil) or gaseous state (e.g. natural gas). It is the end-product of the partial decay of living organisms which once inhabited the world’s oceans.

Renewable energy: Energy sources which are not depleted by use, for example, hydro-power; PV solar cells, wind power and coppicing.

Solar thermal energy: Energy produced by using the sun's rays to heat a gas or liquid that then performs useful work, such as powering an electrical generator. Electricity from solar thermal power plants is now nearly competitive in cost with electricity from conventional fossil-fuel power plants.

Stratosphere: Highly stratified and stable region of the atmosphere above the troposphere extending from about 10km to 50km.

Sustainable development:  Refers to economic development that meets the needs of all without leaving future generations with fewer natural resources than those we enjoy today. It is widely accepted that achieving sustainable development requires balance between the economic, ecological and social.

Technology Transfer:  The process by which energy-efficient or low emission intensive technologies developed by industrialised nations are made available to less industrialised nations. Technology transfer may occur through the sale of technology by private entities, through government programs, non-profit arrangements or other means. 

United Nations Framework Convention on Climate Change (UNFCC):  An international environmental treaty produced at the United Nations Conference on Environment and Development (UNCED), informally known as the Earth Summit, held in 1992. The treaty aimed at reducing emissions of greenhouse gases but was not legally binding.  Superseded by the Kyoto Proto.