A legally-binding target is set on the UK to achieve 100% (net zero) reduction target in carbon emissions by 2050 based on 1990 levels. The Act also established the Committee on Climate Change, allows devolved administrations to set up emissions trading schemes and sets a number of reporting requirements on progress towards the target and climate change adaptation.

Binding Emissions Reduction Target

Part I (as amended by the Climate Change Act 2008 (2050 Target Amendment) Order 2019) sets the Government a target to reduce net carbon emissions by 100% of the 1990 baseline by 2050.

This includes carbon dioxide and other greenhouse gases (currently methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, sulphur hexafluoride and nitrogen trifluouride but this could be expanded to include any other designated greenhouse gas). This will be achieved by setting a carbon budget which the UK cannot exceed for each five year budgetary period.

The targets may be amended in light of scientific developments, or in the event of new greenhouse gases being discovered.

The Secretary of State must submit a report setting out proposals and policies for meeting the carbon budgets for the current and future budgetary periods. Emissions of greenhouse gases from international aviation or international shipping do not count as emissions from sources in the United Kingdom.

Committee on Climate Change 

Part II established the Committee on Climate Change. The committee advises the Secretary of State on various matters relating to climate change including: progress towards targets, and how to achieve the set targets; matters relating to emissions from international shipping and aviation; emissions trading schemes and the impact of and progress in adapting to climate change.

UK Emissions Trading Schemes

Part III allows the authority to set up emission trading schemes to encourage reductions in carbon emissions. Trading schemes may limit activities that lead, directly or indirectly, to emissions of greenhouse gases (for example, by capping emissions from a particular set of activities and allowing trading of emissions within the cap), or they may encourage activities that directly or indirectly lead to a reduction in greenhouse gas emissions or the removal of greenhouse gases from the atmosphere.

Risk and Adaptation
 
Part IV requires the Secretary of State to periodically report on the risk of current and predicted impact of climate change to the UK and to take advice from the Committee on Climate Change (a parallel requirement exists for Northern Ireland). The report should include proposals with timeframes on how to adapt. The Secretary of State and Welsh ministers can give guidance to local authorities and other public bodies on assessing the risks of climate change, preparing reports on this and assessing the progress made towards implementing those proposals and policies.

Amendments to other Legislation

The Act made further changes to support emissions reductions:

• amendments to the Energy Act 2004 to improve the operation of the renewable transport fuel obligations (RTFO);
• a power to introduce charges for single use carrier bags;
• an amendment to the Environmental Protection Act 1990 to allow local authorities to pilot incentive schemes to encourage household waste minimisation and recycling;
• amendments relating to the Certified Emissions Reductions Scheme;
• powers and duties relating to the reporting of emissions by companies and other persons; and
• a duty to make annual reports on the efficiency and contribution to sustainability of buildings on the civil estate.

This Act requires the introduction of mandatory reporting of emissions by companies. The Companies Act 2006 (Strategic Report and Directors's Report) Regulations 2013 require that quoted companies report greenhouse gas emissions in their directors' reports.