Fossil abstinence isn't working - climate expert

Just "saying no" to fossil fuels isn't working, says climate expert Prof Myles Allen. Speaking on Sunday with Laura Kuenssberg, Prof Allen used a lump of coal to explain how burning fossil carbon will result in one degree of global warming. It was the first time a prop has been used on the programme. He also encouraged politicians to speak to energy supply companies and get them to deal with the carbon dioxide they generate.