Climate change: Expert says just saying no to fossil fuel doesn't work

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.