The marvellous Prof Tim Flannery was once described by the Financial Times as akin to a cross between Charles Darwin and Indiana Jones for his pioneering mammalogy and paleontology field work. But he gave up this adventurous life to focus on climate change writing and campaigning. Tim drops into the studio and we discuss why, and talk about his new book (his second follow up to the highly influential The Weather Makers): Sunlight and Seaweed: An Argument For How To Feed, Power, and Clean Up The World.