Professor Bjorn Lomborg is director of the Denmark-based Copenhagen Consensus Centre. "'Trying to make fossil fuels so expensive that nobody wants them is just never going to succeed,' Professor Lomborg said. 'It's politically impossible and it's economically a bad idea. That's why, instead of making fossil fuels so expensive nobody wants them, we need to make green energy so cheap everyone wants it.' He said the cost curves of all green energy options had been coming down over the past 30 years, creating a huge opportunity."