According to a research briefing by the House of Commons library the UK Government would still be bound by the climate targets under the Climate Change Act 2008, but that a UK exit from the European Union following the referendum on June 23rd could increase the UK's focus on domestic power generation.
The briefing paper says that this could especially be the case if exit resulted in poorer security of supply through decreased interconnectivity to Europe, reduced harmonisation of EU energy markets, or less investment into the UK by multinational companies.
The paper highlights the general direction of travel across Europe - on energy and climate change - towards a more transparent and competitive energy market that extends across national borders and suggests that the UK would be unlikely to want to reverse that.
An exit would, though, affect the UK’s international climate targets under the United Nations Conference on Climate Change (UNFCCC). Currently the UK negotiates as a part of the EU block and has internally set targets that, together with those of other Member States, aims to meet the EU’s overall target.
Withdrawal from the EU would have to address that lack of a UK specific target under UNFCCC. It was also widely recognised in the competency review that the negotiating as part of an EU block was beneficial as it had more influence at an international level than if individual Member States acted alone.