Speaker: Sir Nicholas Stern, IG Patel Professor Economics at the London School of Economics. Head of the Stern Review on the Economics of Climate Change published in October 2006. Climate change poses severe risks to the economies and societies of the planet. This risk can be radically reduced with strong and timely action. If the appropriate economic and other policies are designed well and put in place now, then the costs will be much smaller than the damages averted. The policies do not imply the curtailment of economic growth and development. On the contrary, business-as-usual would eventually be the anti-growth strategy. Strong and timely measures must be on a global scale. The challenge requires international collective action: the problem is global in its origins and global in its impacts. This global action should be both equitable and efficient. A global deal should be constructed in the next two years. It is urgent both because world emissions should peak within 20 years if risks are to be kept to tolerable levels and because carbon markets will be damaged if there is no agreement well ahead of 2012, the Kyoto expiry date. The key elements of a global deal will be examined. The discussion will also examine the economics and ethics behind both the deal as a whole and the individual elements.