IPCC
The UN's Intergovernmental Panel on Climate Change, which surveys and summarises the work of climate scientists from around the world in authoritative reports.
Carbon dioxide / CO2
The most significant greenhouse gas, emitted primarily by the burning of fossil fuels in power stations, cars and elsewhere.
Methane
A greenhouse gas 20-24 times more powerful than CO2, emitted primarily by agriculture and decomposing waste.
Volatile organic compounds (VOCs)
VOCs are organic chemical compounds that have high enough pressures to significantly enter the atmosphere. The most common VOC is methane and common artificial VOCs include paint thinners, dry cleaning solvents, and some constituents of petroleum fuels. VOCs can damage soil and groundwater and on escaping into the air contribute to air pollution.
Feedback loop
A climate effect that is self-reinforcing. For example, melting ice reveals dark-coloured sea, which absorbs more heat than the ice would have done.
Greenhouse gas
Any gas which contributes to the greenhouse effect.
Ozone / Ozone hole
Ozone is a gas (a variant of oxygen) that acts as a greenhouse gas at certain altitudes. However, the 'ozone hole' above Antarctica is essentially unrelated to global climate change.
Kyoto Protocol
A treaty, ratified by most of the developed world (though not the US or Australia), to reduce emissions of greenhouse gases by 2012, relatively to 1990 levels.
Carbon footprint
The total greenhouse emissions, usually measured in tonnes of CO2, that a company, individual or household is responsible for.
Climate neutral / carbon neutral
A product, person or company that has had its total emissions balanced out by a contribution to a carbon offset scheme.
Land-use changes
Deforestation and other changes to the natural world. Such changes, primarily deforestation, account for around a fifth of human-caused CO2 emissions.
Contraction & convergence
A model for reducing global emissions which sees the total permissible emissions reduce over time (contraction) and shared equally between the global population (convergence).
Gigatonne A billion tonnes.
The world currently emits roughly 26 gigatonnes of CO2 each year.
Sequestration / Carbon Capture & Storage
The process of burying CO2 (usually in aquifers or old oil wells) to avoid it being released into the atmosphere from a source such as a power station.
Greenhouse effect
A natural phenomenon whereby the atmosphere is kept warm by the presence of gases which absorb heat that otherwise would be lost to space.
Food miles
The distance travelled by food from farm to plate. Food transport is a growing source of carbon emissions (though arguable less significant that its press coverage would suggest).
Anthropogenic emissions
Greenhouse emissions caused by humans rather than natural sources.
Gulf Stream
One part of a ocean-driven cycle that brings hot air to northern Europe from the American tropics. Climate change could reduce this impact thereby making the UK colder.
Hurricanes / Cyclones / Typhoons
Various names for a type of severe tropical coastal storm. Climate change is expected to increase the average intensity of such storms.