How should the scale and the nature of the immense risks appear to face from unmanaged climate change influence the way frame both the economics and the approaches to the values or ethics which bring to the policy analysis? If fail to understand the issues of policy towards climate change in terms of the management of these great risks our policy suggestions are likely to be profoundly misleading. The policy analysis will have to embrace both ethics and economics, which place the magnitude and nature of the risks at centre-stage and are capable of tackling issues of scale of impacts which lie outside more familiar methods or perspectives which may be appropriate for smaller perturbations or effects. This is a paper about the economics of growth and distribution in the context of the immense
risks and long time horizons associated with climate change, but its focus and central subject matter is the ethical and equity issues which are raised.