Should CERN be spending $17 billion on a new atom smasher whilst we face, climate change, the most pressing crisis of our time? Materials-turned environmental scientist Mark Miodownik and CERN physicist Kate Shaw debate the issue. One of the issues Mark argues more people should be tackling are the climate change driven forest fires which recently ravaged Chile and killed more than 100 people. Chilean climate scientist Raul Cordero discusses the factors which led to the devastating fires. And Nasa physicist and oceanographer Susanne Craig explains their freshly launched satellite PACE, which hopes to get a better picture of our changing oceans and use this information to tackle climate change. A quest Nasa manages to achieve whilst also trying to answer the big questions about our universe. Presenter: Roland Pease Producer: Ella Hubber Production co-ordinator: Jana Bennett-Holesworth (Photo: Firefighters work at the Botanical Garden after a forest fire in Viña del Mar, Chile, 4 February, 2024. Credit: Javier Torres/AFP)