This week the UN Climate Change Conference has been happening in Bonn. This meeting is the next step for governments to implement the Paris Climate Change Agreement, which entered into force last November and sets out strategies to try to limit the rise in global temperatures to below 1.5 degrees C. With these targets in minds researchers the world over have been exploring various ways to reverse global warming. One suggestion is to spray about 5 million tonnes of reflective sulphur particles into the high atmosphere to temporarily reduce the intensity of sunlight and cool things down. Scientists at the University of Exeter have plugged the proposals into a complex climate simulator to find out what the consequences might be. Chris Smith spoke to Jim Haywood...