Climate Talks Jargon buster

With many thanks to The Guardian's Damian Carrington

Copenhagen: The venue in December for the final UN negotiations to deliver a successor to the Kyoto treaty. There are preparatory meetings in Bangkok and Barcelona before then.

Carbon intensity: How much fossil fuel you have to burn to make something or deliver a service. Reducing carbon intensity does not mean cutting overall emissions, but it does mean that a country can expand its economy without driving up emissions at the same rate.

Implicit targets: A diplomatic phrase deployed by India to describe targets India has chosen for itself and for which it will not be held to account by anyone else. Appearing to cave in to foreign demands for specific cuts would be political poison in Dehli.

Mitigation: This simply means actions to reduce global warming, most importantly cuts in greenhouse gas emissions.

Afforestation: The replanting of trees. About 20% of all global carbon dioxide emissions come from the destruction of forests. Preventing that is the main focus of the UN talks but China is also keen on creating new forests.

Cap and trade: One way of setting a limit on greenhouse gas emissions for a region or industry. Polluters are given carbon permits that add up to the cap. They can then sell permits if the have cut their emissions to those who have not. In theory, it allows a market to deliver cuts efficiently.

Carbon tax: A direct tax on activities that result in carbon emissions. Much less bureaucratic than cap-and-trade but cannot deliver an exact cut in overall emissions.

Offsetting: Paying for reductions in emissions elsewhere to compensate for polluting activities. Popular on a voluntary basis for flights, but criticised on a national level for allowing rich nations to butt their way out of making cuts at home.

Peak emissions: The time at which global greenhouse gas emissions stop growing and begin to fall. Scientists say that year must be 2015 if dangerous climate change is to be averted but current trends will not achieve this.

Intergovernmental Panel on Climate Change (IPCC): The international scientific body, involving thousands of scientists, used by the UN since 1988 to provide a neutral source of information on climate change. Its reports are approved by national governments. It was awarded the Nobel peace prize along with Al Gore.