The UK’s greenhouse gas emissions reduction targets are legally bound by the Climate Change Act 2008. They are:

• A reduction of at least 34% by 2020
• A reduction of at least 80% by 2050

The UK believes it important to set out the trajectory by which these reductions can be achieved by 2050. So on 22 April 2009, the Government announced the first three "carbon budgets". These are five-year caps on emissions, with three budgets set at any one time. The first three carbon budgets will run from 2008-12, 2013-17 and 2018-22, and are set to reduce carbon emissions by at least 34% by the end of 2022.

In July 2009 the Government will present to Parliament a White Paper setting out how it intends to meet the carbon budgets and achieve the other policies set out in the Climate Change Act. The submission of this White Paper is itself one obligation under the Climate Change Act, to ensure that the UK follows a long-term strategy towards reducing emissions and moving towards a low-carbon economy.

Since the UK has agreed that the EU target should rise from 20% to 30% in the event of an international agreement at Copenhagen, it is probable that the UK’s unilateral 2020 target will also increase. The Committee on Climate Change has recommended that the target should be raised to 42%. The Government is considering this recommendation and will respond formally once the international deal has been reached.