Co-founder of Extinction Rebellion - Roger Hallam

Back in 2015, the nations of the world made a formal commitment to keep global warming below 2 degrees centigrade. So much for fine words; global greenhouse gas emissions are still rising. The data suggest the planet is warming at an alarming rate. What to do about it? Stephen Sackur interviews Roger Hallam, the co-founder of Extinction Rebellion, a movement dedicated to mass resistance and civil disobedience; how far are these climate rebels prepared to go? Image: Roger Hallam (Credit: Ollie Millington/Getty Images)