Glossary of common climate change terms

Adaptation: ways of coping with the impacts of global warming on species, ecosystems and human society.

Anthropogenic: caused by human activities.

Biodiversity: life in all its forms, essential to maintaining functioning ecosystems that provide services essential for human survival and quality of life.

Carbon capture and storage (CCS): the process of capturing greenhouse gas pollution from coal or gas power plants and storing it underground instead of releasing it into the atmosphere. CCS could reduce emissions from a power plant by up to 80%.

Carbon credit: used in emissions trading schemes (see emissions trading), where one credit gives the owner the right to emit one tonne of CO2.

Carbon cycle: the exchange and movement of carbon – a chemical element – through the atmosphere, oceans and water, living things, soils and geological deposits.

Carbon dioxide (CO2): the most common greenhouse gas (other major greenhouse gases include methane and nitrous oxide). Carbon dioxide is released by burning fossil fuels, landclearing/deforestation and cropping.

Carbon neutral: where an individual or company’s carbon emissions are effectively reduced to zero through a combination of reducing energy consumption, using renewable energy and offsetting the remainder by (for example) planting trees to absorb carbon dioxide from the atmosphere.

Carbon offsetting: where an investment is made in a project that will lead to the prevention or removal of carbon dioxide from the atmosphere (for example, planting trees or building renewable energy power stations to avoid the construction of coal ones).

Carbon price: puts a price on greenhouse gas emissions to create a disincentive for their release (and incentive to capture or avoid them). A carbon price can be imposed through a carbon tax, an emissions trading scheme (which fixes the emission level and allows price to vary) or a variety of other mechanisms.

Carbon sequestration: the uptake and storage of carbon (eg by trees, or burying underground).

Carbon sink: entities like forests and oceans that store more carbon than they release.

Clean coal: technologies designed to reduce the amount of CO2 emitted by coal-fired power stations.

Clean development mechanism (CDM): one of three market mechanisms established by the Kyoto Protocol, designed to promote emission reduction projects in developing countries.

Climate change: significant changes from one climatic condition to another, commonly referring to the increase in Earth’s surface temperature caused by human activities. Also often called global warming, anthropogenic climate change, anthropogenic global warming and the enhanced greenhouse effect.

Dangerous climate change: a level of climate change that will have severe impacts on societies, economies and the natural world. WWF defines dangerous climate change as a rise in average global surface temperatures of 2°C or more (above pre-Industrial Revolution average surface temperatures).

Emissions trading: a scheme that allows companies to either reduce emissions or pay for the right to pollute (with the money paid being used to reduce emissions elsewhere, often in developing countries).

Energy efficiency: the amount of energy needed to provide the same amount of heating, cooling or other energy service from different sources, appliances or systems.

Fossil fuel: fuel of biological (plant and animal) origin that has become fossilised over millions of years. Largely comprised of carbon and hydrogen, coal, natural gas and oil are all fossil fuels.

Global warming: see climate change.

Greenhouse gases: gases such as carbon dioxide, water vapour, methane, nitrous oxide, ozone, and various fluorocarbons that absorb and re-emit heat from  the solar radiation that hits the Earth into the atmosphere.

Greenhouse effect: the effect created by the band of greenhouse gases that blanket the Earth. The greenhouse effect keeps the Earth’s surface within a temperature range that makes life on Earth (as we know it) possible.

Greenhouse pollution: pollution by humans of the Earth’s atmosphere by the release of excessive greenhouse gases. This increases the volume of gases in the atmosphere, traps more solar radiation and leads to global warming.

Greenhouse gas intensity: the volume of greenhouse gases emitted per unit of energy or economic output. It is a relative measure in that, if the economy is growing, greenhouse intensity per unit of economic output may be falling but greenhouse gas emissions may be increasing in absolute terms. Greenhouse gas intensity is to be contrasted with greenhouse gas emission reductions, where the volume of gases emitted falls in absolute terms.

Intergovernmental Panel on Climate Change (IPCC): the United Nations scientific body that investigates the causes and impacts of climate change, and publishes special scientific reports.

Kyoto Protocol: an international agreement made in 1997 that sets emissions reduction targets for developed countries and establishes mechanisms to reduce the emissions of developing countries. The Kyoto Protocol is an addendum to the United Nations Framework Convention on Climate Change.

Mitigation of global warming: actions to reduce or avoid greenhouse gas emissions, in order to avoid global warming.

MRET (Mandatory Renewable Energy Target): a scheme to increase the amount of electricity generated from renewable energy sources.

Ppm or ppb: parts per million or parts per billion, a measure of the amount of greenhouse gas emissions in the atmosphere.

Renewable energy: energy derived from the wind, sun, tides and other sources that, for all practical purposes, cannot be depleted.

Sea level rise: one of the impacts of global warming.

Sequestration: the removal of greenhouse gases from the atmosphere into trees, oceans or deep underground.

UNFCCC (United Nations Framework Convention on Climate Change): an international treaty that requires world governments to avoid dangerous levels of climate change.