Contributor(s): Dr Sam Fankhauser | Economic motives rather than ethical concerns will be ultimately what prevents runaway climate change, argues Dr Sam Fankhauser, an economist based at LSE's Grantham Research Institute on Climate Change and the Environment. In a new short video produced as part of the Big Ideas series for The Independent website Dr Fankhauser explains that he doesn't believe that we can prevent the worst effects of climate change on a voluntary basis.