KT Tunstall and Razorlight have joined thousands of people in London's Trafalgar Square to call for urgent action on climate change. Simon Amstell was there too.
Tunstall took to the stage and told the crowd: "I'm here today because of the situation with the environment. We are screwing it up, we are making a real mess. Today is about raising awareness that we need to change our behaviour. I'm not trying to tell people what to do. I'm not perfect. I boil the kettle twice sometimes, but it's about knowing that's a bad thing to do and wanting and needing to change that behaviour."
And here's what the ever popular Johnny Borrell, out of Razorlight, said about the event: "I'm here with everybody else to register my voice essentially and to be heard for our concerns about the environment. The whole thing about climate change is an issue I hardly knew anything about. It didn't register until I saw Al Gore's film recently. I walked out of the cinema saying we've got to do something about it. I phoned up Friends of the Earth and they asked me to do this today."
The event was organised by the Stop Climate Chaos Coalition and was timed to coincide with global climate talks in Nairobi.