Everyone is green now, at least in theory. A warming planet has panicked the world into looking for alternatives to fossil fuels even as billions of people begin to achieve the sort of luxurious Western lifestyle that will, without reform, cook the Earth. If the science of climate change is fast-moving, the politics are even faster, with a huge array of treaties, promises, pledges and targets giving the appearance of lots of action—but with little actually being achieved. Three books take very different approaches to sizing up the problem.

Alamy

Anthony Giddens, a professor at the London School of Economics, is a sociologist most famous for developing the “Third Way”, the centre-leftish political philosophy espoused by Tony Blair and Bill Clinton. His book argues that the scale of the climate-change problem and the difficulty of reconciling greenery with development demands a new political approach.

The result is a wide-ranging book that covers everything from renewable energy to carbon trading and the practicalities of adapting to a world with deeper seas and fiercer weather. Lord Giddens (he was ennobled in 2004) gives much good advice. He chastises eco-warriors for their relentlessly downbeat message, arguing that people are more likely to change their habits if offered a happy future to look forward to rather than a bleak one to avoid. He rejects the hair-shirt ideals of many greens as unlikely ever to appeal to most voters. And he argues against the idea that climate change is too big a problem for a democratic system to deal with.

But the price of breadth is a lack of depth that may leave curious readers frustrated. Part of the problem is a tendency to affectation. The rather pedestrian observation that distant, abstract crises tend not to change people’s behaviour even if the consequences are extremely unpleasant is christened “Giddens’ paradox”, and the opening chapter mentions every fashionable meme from the internet and social networks to Barack Obama’s “yes we can” campaign slogan. Overall, there is little in the book that is truly original. But it is conveniently packaged and Lord Giddens’s reputation among policy wonks (as well as an endorsement from Mr Clinton) will propel it onto shelves in high places.

Those who crave something less woolly will prefer Sir Nicholas Stern’s book. Sir Nicholas is a former chief economist at the World Bank and author of an influential study of climate-change economics for the British government. His book addresses the argument in cost-benefit terms, and concludes that spending 1-2% of global output to avoid a significant temperature rise is a bargain worth taking—a similar conclusion to that in his original 2006 study. But the book is written for a wider audience than the official report, and incorporates some more recent (and worrying) findings from climate science.

Least woolly of all is David MacKay’s book (which can be bought or downloaded free from www.withouthotair.com). Irritated by the waffle that often surrounds discussions of energy and climate change, Mr MacKay, a physicist at Cambridge University, has chosen to illustrate the challenge of breaking our fossil-fuel addiction armed only with the laws of physics, reams of publicly available information and the back of an envelope.

Mr MacKay favours no particular technology. He is concerned only that proposals to decarbonise the economy should add up. But his refreshingly hard-headed approach (confined to Britain, but easily adapted to other countries) comes to some sobering conclusions. Meeting Britain’s energy needs from onshore wind power would require covering literally the entire country in turbines, even assuming that the wind was guaranteed to blow. If only 10% of Britain were covered then wind could provide roughly a tenth of total demand. Switching every piece of agricultural land to biofuel production would provide just 12% of the requisite juice.

It is a similar story for offshore wind, tidal and wave energy, all of which make the claims of green advocates that Britain has a “huge” renewable resource look somewhat hollow, especially since the book ignores questions of costs and focuses purely on physical limits. To make a dent in fossil-fuel consumption without using nuclear power, renewable-energy facilities will have to be “country-sized”, with offshore wind farms bigger than Wales and huge solar-power arrays in sunny deserts piping power to cloudier nations.

Although Mr MacKay’s conclusions are fascinating, much of his book’s appeal lies in its methods. Ballpark calculations are a powerful way of getting to grips with a problem. The book is a tour de force, showing, for example, how the potential contribution of biofuels can be approximated from just three numbers: the intensity of sunlight, the efficiency with which plants turn that sunlight into stored energy and the available land area in Britain. As a work of popular science it is exemplary: the focus may be the numbers, but most of the mathematical legwork is confined to the appendices and the accompanying commentary is amusing and witty, as well as informed.

With global climate-change and energy policy consisting mostly of feel-good rhetoric rather than action, Mr MacKay’s reminder that the natural world does not care for political expediency—summed up in Richard Feynman’s famous observation that “nature cannot be fooled”—should be engraved on environment-ministry doors the world over. For anyone seeking a deeper understanding of the real problems involved, “Sustainable Energy—Without the Hot Air” is the place to start.

Sustainable Energy: Without the Hot Air.
By David MacKay.
UIT Cambridge; 384 pages; $49.95 and £45

The Global Deal: Climate Change and the Creation of a New Era of Progress and Prosperity.
By Nicholas Stern.
Public Affairs; 256 pages; $26.95. Published in Britain as "Blueprint for a Safer Planet"; The Bodley Head; £16.99

The Politics of Climate Change.
By Anthony Giddens.
Polity Press; 264 pages; £50. To be published in America by Polity next month

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