Environmental protesters are hoping to 'shut down' London and force the Government's hand on climate change on 15th April. David Humphreys, Professor of Environmental Policy at The Open University gave a speech outside the Houses of Parliament and was interviewed on the show. 

You can listen to David's interview at https://www.bbc.co.uk/sounds/play/p074mdkt [starts 1:49:11, ends 1:57:08]