Four authors of the Stern Review on the Economics of Climate Change, and Dennis Anderson who provided advice and background papers for the Review, make a final rejoinder on the debate about the Review that has occupied recent issues of this journal. They respond to comments in the present issue by Carter et al., by Henderson, and by Tol and Yohe. Carter et al. continue to argue against a growing body of scientific evidence and a growing consensus on that same evidence. The source of their critique is, first, a distinctly partisan, and increasingly untenable, position on the broad range of available scientific evidence and, second, a mistrust of the international consensus-building exercise centred on the Intergovernmental Panel on Climate Change. Henderson is also largely preoccupied with the latter, procedural issues. Tol and Yohe focus on economic arguments. Their critique is rather narrower in focus and concerns the way in which abatement costs were calculated in the supporting work carried out by Dennis Anderson. It rests on basic confusions and misconceptions, many of which were explained in previous contributions. However, readers of World Economics might be more interested in a broader reflection: how would the Stern team, following the debate of the last eight months, assess the approach, policies and arguments set out in the Review? Their view is that their analyses and policy proposals, and the arguments in support, are sound and have stood up well to scrutiny. In other words, they were right and for the right reasons. Central to many critiques of the Review is a fundamental misunderstanding of the role of formal, highly aggregated economic modelling. Nevertheless, the Stern team have argued strongly and in their view convincingly that, even within the confines of formal economic modelling, the concerns raised by a small group of commentators do not overturn their basic conclusion that the cost of action is much less than the cost of inaction. The critics here fall short by failing to simultaneously afford the necessary importance to issues of risk and ethics.

Those who deny the importance of strong and urgent action on climate change essentially offer one of, or a combination of, the following arguments. First, there are those who deny the scientific link between human activities and global warming; most people, and the vast majority of scientists, would find that untenable given the weight of evidence. Second, there are those who, while accepting the science of anthropogenic climate change, argue that the human species is very adaptable and can make itself comfortable whatever the climatic consequences; given the scale of the outcomes that we now have to regard as possible or likely under business-as-usual (BAU), this must be regarded as reckless. Finally, there are those who accept the science of climate change and the likelihood that it will inflict heavy costs, but simply do not care much for what happens in the future beyond the next few decades; most would regard this as unethical. This paper deals primarily with the latter two arguments. An appendix addresses confusions and misconceptions about The Stern Review and responds to points made by critics in previous issues of this journal and elsewhere.