Planet Earth - Winter 2006
Challenging the sceptics
Alan Thorpe, Chief Executive
The Prime Minister described the Stern Review of the Economics of Climate Change as "the most important report on the future published by the government in our time in office." For NERC-funded scientists the review carries many key messages. A central one is that recent advances in the science of climate change are critically important in determining the economics of climate change. This may seem obvious – how could the science be other than important? But if all we need for the economic evaluation is the average global warming then we could use Arrhenius's calculation in 1896, which showed the relationship between global average temperature and carbon dioxide in the atmosphere!
The Stern review points out that it is the most recent advances in climate science that have allowed economists to make this evaluation. A key element is the development of probabilistic predictions of climate change – where you state the likelihood of a particular change happening. Economists can use this information from scientists to properly factor into economic valuations the effects of low risk but high impact climate changes for the first time. Probabilistic climate predictions are not without scientific controversy. It's the job of science to reduce uncertainty but we must remember that we have to estimate our error bars, that is, we must quantify uncertainty. We do this by producing a set of nearly identical models that differ in small ways so we can explore the range in uncertainty in our understanding of climate processes. The various predictions are then collected together into an ensemble that can be used to estimate the risk or uncertainty in those predictions. We also have to factor in future greenhouse gas emissions. Ensemble climate prediction is still a young science but one that is having an immediate impact, as witness the Stern review.
Another critical factor is that if we want to assess the economic impact then we have to aggregate the sum of individual impacts of climate change on people and society. These include changes to: air and water quality, biodiversity, flooding, energy and food availability. To figure out those impacts we need a local to regional picture of the range of climate change in the next decades. This is again an area at the forefront of the science and we have to admit that at present there is great uncertainty in how, for example, rainfall will change as the climate warms. New scientific research is urgently needed. International Polar Year (IPY), which starts in 2007, is a good example of a research programme to increase knowledge on the regional effects of climate change. The Arctic has already warmed much more rapidly than the global average and involves, as yet uncertain, complex positive feedbacks. Science relating to IPY figures large in this issue of Planet Earth.
The Stern review has placed firmly centre stage a truly multidisciplinary approach to the research involving physical and biological science but also engineering, economics, social science and many other disciplines. NERC-funded scientists rightly pride themselves on working across the disciplines (See QUEST article - "The big picture") but these new drivers require the degree of multidisciplinarity to go to another level. This was appreciated before, but I think for many, Stern has shown the power of a complete or end-to-end risk-based analysis of the problem. The Research Councils submission to the upcoming comprehensive spending review majors on such a new multidisciplinary programme on living with environmental change, which NERC leads. The time is right for this and it addresses the biggest challenge for the planet.
There are still some that dismiss the science of climate change. In light of the Stern review, it is hard to understand how people can make statements like: climate change is all down to variations in the sun's radiation, or, we used to worry about an impending ice age. I am willing, on behalf of NERC, to accept the challenge of a public debate with any sceptics to try to correct misinformation with actual scientific knowledge.
Climate change sceptics – debate the issues with Alan Thorpe on our discussion forum, "the NERC Climate Change Challenge".
About Planet Earth
External links
Related links