The UK has successfully halved its territorial emissions since 1990, it has had consistent climate policies for over 18 years and continues to be seen as a climate leader internationally while other nations are considering reducing their climate commitments. In this perspective, I argue that the legislated Climate Change Act and the independent Climate Change Committee (CCC) has had a lot to do with the success by building trust, guiding progress and giving businesses confidence to invest. Around 75 countries now have similar climate framework laws with many similar to the UK model. However, we are moving to a world where future progress is becoming politically contested and geopolitical pressures are mounting. This perspective reflects on 18 years of UK progress under the Act and presents thoughts on the future and the benefits of international cooperation.