The chapter begins with the historic announcement by then UK Prime Minister Theresa May of a net-zero emissions target. It looks at the theory of regulation as applied to companies, and EU and UK energy and climate law in particular. With a focus on the Climate Change Act 2008, this chapter highlights some of the unique characteristics of the independent and expert-based nature of the Committee on Climate Change, and its relationship to climate science. It also looks at the increasing overlap between the reporting requirements on directors under the Companies Act 2006 and the Climate Change Act 2008. It focuses on the desire for a ‘Green Brexit’ as the motivation behind the UK Environmental Bill 2020, the Clean Growth Strategy and plans for a UK emissions trading system. The chapter includes a section on energy companies’ evolving approach to climate and energy regulation, with a focus on market-based mechanisms like the EU emissions trading system and Article 6 of the Paris Agreement.