We, like many other organisations, recently declared a climate emergency and biodiversity crisis. In doing so we recognise that these crises are inextricably linked and cannot be addressed in isolation , and nor can they be fully understood without reference to social issues. We acknowledged that nature-based solutions, which our membership are well placed to instigate, must play a key role in mitigating against, and adapting to, climate change, and reversing ongoing declines in biodiversity. This briefing sets out what nature-based solutions are and why we should use them.