The UK's Climate Change Act is the world's first long-term legally binding framework to tackle the dangers of climate change.
Source: Department of Energy and Climate Change, UK

The UK has passed legislation that introduces the world's first long-term legally binding framework to tackle the dangers of climate change. The Climate Change Bill became law in 2008. The Climate Change Act creates a new approach to managing and responding to climate change in the UK, by: setting ambitious, legally binding targets; taking powers to help meet those targets; strengthening the institutional framework; enhancing the UK's ability to adapt to the impact of climate change; and by establishing clear and regular accountability to the UK Parliament and to the devolved legislatures.