For all the mixed messages and misinformed rockstars on display at Live Earth at least its number 1 job was to focus attention on the environment. Radiohead are embarking on a tour that I imagine will add to their bank balance or either directly through ticket/tshirt sales or through promotion of the album.
They have enough money, why don't they make a statement that they can't tour anymore due to environmental reasons.
(I'm just thinking out loud folks, i'm not 100% sure what my position is).
Because they are a band and this is what bands do. A solution to climate change is not for us all to become seaweed farmers but to make sensible decisions about how we affect the environment.