Climate change is high on the agenda at the G8 summit in L'Aquila. Leaders of the major industrial countries are discussing targets for reducing global warming with counterparts from developing countries. Here are the promises that countries and supra-national bodies have already made.

The G8 leaders said on Wednesday that rich nations should cut emissions by 80% by 2050, while the world overall should reduce them 50% by 2050.

They said they had agreed to try to limit global warming to just 2C (3.6F) above pre-industrial levels.

The EU has promised a 20% cut in emissions of greenhouse gases by 2020, compared with 1990 levels. It has said that the target will be increased to 30% if there is a satisfactory international agreement.

It also says 20% of the total energy mix should come from renewables by 2020, and there should be a 20% cut in energy consumption by the same year.

President Barack Obama is backing a law which would set a target to cut emissions by 17% by 2020 and 83% by 2050 compared to 1990 levels. But the US Senate might block the proposals or reduce the targets.

Japan has set a target for cutting emissions by 15% by 2020 but the baseline for this reduction is 2005, not 1990. This makes a significant difference because emissions were 6% higher in 2005 than they were in 1990.

The Australian government says it will cut emissions by 5 - 25% by 2020 compared to 2000 levels depending on what other countries agree, and by 60% by 2050. It is also planning to introduce an emissions trading scheme but it faces opposition in the Australian Senate.

China has set domestic targets for energy efficiency and use of renewable energy but nothing specifically on emissions. It may introduce an "emission intensity" target, i.e. the level of emissions for each unit of economic output. But that has not happened yet.

India has not set targets to cut emissions.

Brazil has not set targets to cut emissions. It is probable that any new deal negotiated at the United Nations climate change conference in December will place obligations on China, India and Brazil. These will probably take the form of limits on the future growth of emissions and, in the longer term, cuts in emissions.