Professor Sir Brian Hoskins, director of the Grantham Institute for Climate Change at Imperial College London, said a greater sense of urgency about tackling climate change was needed.

BBC: Scientists call for action to tackle CO2 levels

Bob Ward, policy and communications director for the Grantham Research Institute for Climate Change and the Environment in London, said the warming of the Earth's surface was unequivocal.

BBC: Global warming 'confirmed' by independent study

Stern is the chair of the Grantham Research Institute on Climate Change and the Environment at the London School of Economics and also chair of the Centre for Climate Change Economics and Policy (CCCEP) at Leeds University.

FORBES: Why Most Forbes Readers Know More About Global Warming than Most Climate Scientists