China’s 12th five-year plan represents a radical change in strategy. China now sees its future growth within this strategy and accordingly as driven by: a rising share of consumption; moving to a low-carbon economy; and innovation. Two indicators are examined – capital efficiency and the relationship between greenhouse gas emissions and output. These help us to understand the scale of the challenges and possibilities in China over the coming decades. The power of China’s example will be immense in influencing the world’s transition to a low-carbon economy and thus how successful the world will be in managing the huge risks of climate change. The 12th plan is very likely to establish China as a leader in the new energy-industrial revolution and demonstrate to the world the potential of this revolution. The implications for the rich countries from such radical change are profound and they should be discussing now how they will handle and respond to such massive change.

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.

This paper highlights the basic economic principles behind the policy recommendations in the Stern Review and takes forward the analysis and proposals of the Review. It is written in the light of developments since the Review was published, reflecting on interaction with policy makers and analysts around the world and other commentators on the Review. Its authors argue that across the world, progress of understanding and developing the necessary policy response to climate change has been especially rapid in the last few months. Building on these developments and the Review team’s initial analysis, they outline a policy programme going forward for international collective action to tackle climate change.

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.