As evidence of climate change and mass extinctions becomes ever harder to ignore, a new tide of eco-activism is making waves. Schoolchildren across the world have been coming out on strike, with Swedish student climate activist Greta Thunberg meeting Pope Francis this week. Meanwhile, a movement calling itself Extinction Rebellion continues to occupy key locations in central London and elsewhere, stopping traffic, gluing themselves to things, even smashing the occasional oil company window. Their message is clear – they want action on climate change and they want it now. But the answers are not simple, and the approach can be divisive. So what are the best tactics and strategies for such an epic fight? Is the latest wave just a western phenomenon, or are the developing countries most at risk from climate change also on board? How important are arguments about social justice, and human rights? Are governments actually paying attention? And what lessons have been learnt from the eco-warriors of the past? Ritula Shah is joined by a panel of activists and experts to discuss the new green activism. Photo: An environmental campaigner is carried by police officers at Oxford Circus during the protests by Extinction Rebellion in April 2019 in London. Credit: Leon Neal/Getty Images)