In this week's programme, Alison Benjamin is joined in the studio by John Vidal, the Guardian's environment editor, and ethical living editor Leo Hickman.
They discuss whether Ken Livingstone's bid to make the London mayoral race a green election will pay off and what his Tory rival, Boris Johnson, has to offer on the the environment.
John Vidal asks the London mayor about why he is behind in the polls if voters are as eco-conscious as he says they are. Is Ken's green ticket just too radical for most Londoners?
Also in the show, we hear from Brazilian eco-town planner, Jaimer Lerner, who as three-time mayor of Curitiba turned a grimy, congested city into an example of green living.
And finally, Philip Igoe tells us about his campaign to get a car club in every neighbourhood in Britain.
