It comprises eight chapters, each consisting of a longish academic paper plus 14 two, occasionally one, "perspective papers" which are in effect both open peer reviews and alternative views. There are a total of 15 main article authors, plus 16 perspective paper authors.
At the end of the work five expert economists, the "Copenhagen Consensus Expert Panel", review and rank the work of the chapter authors, answering, individually and as a group, the question that Lomborg had posed them:
"If the global community wants to spend up to, say, $250 billion per year over the next 10 years to diminish the adverse effects of climate changes, and to do most good for the world, which solutions would yield the greatest net benefits?"
While Lomborg managed the whole process, including securing funding for the project from the Danish Government, his direct written input to the book is a four and a half page introduction and a one and a half page conclusion.
While the main authors include a number of scientists and engineers, most are economists, albeit ones whose CVs suggest that they have specialised in the climate and environmental area, and this is primarily a work of economics rather than climate science. This work assumes that climate change is happening, broadly as suggested in the main reports of the IPCC, and asks what should best be done about it.
The chapters deal with eight approaches to solving climate change, including climate engineering, carbon dioxide mitigation, forestry mitigation, market and policy driven adaption and technology led climate policy. Each of these assesses several possible techniques under its heading, costs them, and assesses the cost and benefits of adopting each one. Each chapter is pretty dense - I've had the book for a few days and while I've scanned the lot I have only really digested two of the chapters. If you're not familiar with economics papers and climate science, then this is certainly not bedtime reading! Collectively, and in contrast to the Stern Report of 2007, the authors do not suggest that the strategies that they analysed would be affordable within 1% of GDP, still less that they will be easy to achieve: the technology led chapter authors concluded, for example, that "to substantially reduce global GHG emissions will require a technological revolution" and that "the magnitude of the technology challenge is huge".
The Expert Panel Ranking, delivered in just 12 pages at the end of the book, suggested that the projects with the highest cost benefit were likely to be two climate engineering techniques: marine cloud whitening and stratospheric aerosol insertion, and two technology-led solutions: energy R&D (i.e. research into a wide variety of alternative energy sources) and carbon storage. CO2 mitigation strategies in the form of carbon taxes were rated, by contrast, poor and very poor.
If I have a quibble with this book it is the graphs. Most have quite clearly been created in Excel spreadsheets in which they would have been in colour, and printed in greyscale some are impossible (Figure 7.1 for example!), and several more are very difficult, to interpret satisfactorily.
Much of the initial press reaction in the UK, in the Guardian and on the BBC, for example, has suggested that Lomborg has, in some way, changed his view on manmade global warming, that he has recanted his "denier" views and become a member of "the consensus". I found no basis for this interpretation: Lomborg has always favoured a cost-benefit approach, and has always stated that he believed that the evidence suggests that human activity is contributing to warming the planet. As he said in The Skeptical Environmentalist (p266) "the important question is not whether man-made CO2 increases global temperature, but how much". He said much the same in Cool It, and the authors seem to share the view that AGW is a very major challenge that has to be countered. When I reviewed Cool It I raised the question of whether Lomborg really thought that man was having a significant impact on the planet's temperature, and while I think that this is a question that may still legitimately be asked of him, my reading of this book suggests that while he does not think that a 5 degree global average temperature rise by 2100 is likely, that he thinks that a 2 degree-plus rise is a significant possibility. His primary objective in this work, as it was in Cool It, is to point the world away from responses - like Kyoto and the UN's Copenhagen conference in 2009 - that are likely to be expensive but ineffective and to those that, while still being expensive, may be effective, and which may bring ancilliary benefits, like reducing dependency on oil.
This may not be a book that is going to have a large popular readership, but I am finding it to be worth the effort of study and it's certainly one that ought to be read by politicians and ministers, UN bureaucrats - and climate scientists of all hues.
I have read Lomborg's previous books and was interested in his latest views particularly since the Guardian and others had proclaimed some sort of Damascene Conversion; a Heretic returning to The Faith. This is a heavy book for serious people who are concerned about the best way forward on managing environmental issues within the context of all the other serious challenges facing the world. It is useful for being objective and quantitative in comparing a number of different options for mitigating climate change. The main content comprises a series of papers by leading academics, with alternative conclusions presented by peers with differing perspectives. One may not agree with all the comments (I am a Chartered Engineer thus technically literate and numerate) still it is encouraging to read papers which eschew the emotionally-charged style of "true believers" and to see the data presented upon which the conclusions are based, such that you can judge for yourself. Unfortunately the diagrams are monochrome which impairs their readability. Lomborg contributes the introduction and the summing-up. I found his style and recommmendations to be compatible and consistent with his previous work.