In a perverse way, says Clive Hamilton, we are nearly all climate-change denialists. We tacitly deny the seriousness and severity of the upcoming climate shocks in the way that we continue to live our everyday lives, organise our investment decisions and pensions, cast our political votes and pursue our jobs and businesses. Unlike other writers who are keen to leave us some room for hope, Hamilton offers us a requiem. There can be no business as usual. We messed up and it's already too late - especially after the underachievements of the 2009 Copenhagen Climate Change Conference - to undo the mess. To believe anything else is to deny the climate truth and engage in wishful thinking.

Hamilton makes this argument in stages. First, he reviews the evidence to impress on us how bad the situation is already and how much worse it will get. Then he examines the roots of our denial, both in terms of our resistance to the evidence and in relation to the actors and agencies motivated to deny the truth. Last, he looks at some likely futures and reflects on what we can do about it all.

The rapid review of the evidence is very well done. Hamilton takes a few key articles and uses them to show how little chance there is of limiting the build-up of greenhouse gases and consequent temperature rises: "even if we act promptly and resolutely, the world is on path to reach (a level of CO2-like gases of) 650ppm (parts per million in the atmosphere) ... associated with warming of about 4C by the end of the century". And such a temperature rise, he argues, will likely cross key tipping points, including the irreversible melting of land-based ice or even the release of methane from frozen soils, so that further temperature rises and large-scale environmental changes will follow. He stresses that the official reports of the Intergovernmental Panel on Climate Change (IPCC) tend to err on the side of stating only what can be said with a high level of certainty. Such reports play down likely threats, while many knowledgeable scientists believe that things will probably turn out far worse. Hamilton picks good examples and makes his argument forcefully while keeping the use of statistics and equations to a minimum.

Distinctively, he does not bother to address in detail the arguments of so-called climate sceptics. His focus is on our responses to the troubling implications of the mainstream position; sceptics are beside the point. If, as appears to be the case, the majority of the world's politicians and publics believe in the IPCC's work - after all, nearly all the world leaders turned up in Copenhagen for the summit - then we are already committed to a view in which disastrous warming is very likely, very soon. Why are we - and they - not doing more?

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The question brings us to the heart of the book: the everyday, routine denial of the seriousness of climate change. This is the most original and interesting - but also the most frustrating - part of Requiem for a Species, because Hamilton puts forward so many kinds of explanation for this central problem.

In large part he attributes the lack of serious responses to deliberate obfuscation by the fossil-fuel lobby: it has adapted the denial strategies of the tobacco industry to undermine the science, diminish concerns and encourage complacency. But systemic aspects of the economy are also to blame because high employment and economic well-being have been allied to growth, and growth means more emissions. This is a treadmill we don't know how to escape. There is an ideological element, too, particularly in the US, where environmental limits and proposed treaty obligations may be viewed as assaults on individualism and threats to national sovereignty. Game-theory-type considerations also come into play because nation states are typically reluctant to make major concessions until they are sure others will follow suit; moreover, China's hugely ambitious growth plans seem to render nugatory the actions of even middle-sized industrial powers.

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But Hamilton draws on other explanations as well. The problem is in part one of the human psyche and our psychological adaptations. As philosophers have long pointed out, we all know we are going to die but few of us respond with the urgency and moral seriousness that such knowledge surely implies, at least until death is close. Hamilton invokes evolutionary psychologists' accounts of the nature of the human mind to explain why people may be "hard-wired" to respond to threats with selfish and acquisitive behaviour. Consumer culture also comes in for vicious criticism from Hamilton, who points out that the recent close connection between one's sense of worth and identity and the discerning consumption of products leads to ever-greater demands for goods. Even our conceptual frameworks are implicated because modern, rational science has led to epistemological alienation from nature over the past 300 years.

Many of these arguments are hard to fault, but Hamilton does too little in trying to sort out their relative importance and to clarify their interconnections. If we are "everyday denialists" because the human brain is not very good at handling enormous but still-remote future threats, then perhaps the problem would be every bit as bad even if consumer culture were less rampant.

The struggle to decipher the relative significance of the different kinds of obstacle is made even harder by some of the writer's techniques. Hamilton keeps the text accessible and lively by using lots of examples and vignettes. Britain's own Jeremy Clarkson gets three pages as a representative of a certain style of denialism, but it is unclear whether this means that Hamilton regards the Top Gear effect as particularly influential in contributing to the UK's problems in addressing climate change.

If the problem is so spectacularly Hydra-headed, are there feasible technological routes to prolonging the status quo? Hamilton offers a brisk, well-informed and pessimistic review of the scope for such initiatives as expanding nuclear power, introducing carbon capture and storage and undertaking human interventions designed to offset warming. The last of these - now commonly termed geoengineering - could include the release of sulphate particles in the high atmosphere to block some solar radiation. Hamilton is pessimistic, both because he believes that such strategies would not be effective soon enough and also because he argues that this impulse to manage the environment is itself part of the problem.

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As the reader quickly anticipates, there is to be no happy conclusion to this book. Hamilton is looking for a different kind of "closure", arguing first of all for acceptance that things really will alter for the worse. We should despair and banish false hopes, acknowledge that the world will change irrevocably and commit to what actions we can to reduce emissions.

This is a provocative and sobering book, in which Hamilton shows very clearly that the climate problem is now primarily a question of social science: of psychology and political economy. For my money, he could have done more to systematise his social scientific analyses and to specify the relative importance of the numerous factors he highlights. But this is nonetheless a vivid book and an urgent invitation to do much more detailed social science.

THE AUTHOR

Clive Hamilton is professor of public ethics at the Centre for Applied Philosophy and Public Ethics (CAPPE), a joint centre of the Australian National University, Charles Sturt University and the University of Melbourne.

He undertook his undergraduate degree at the Australian National University before going on to study for a postgraduate degree at the University of Sydney. He then came to the UK to study for a doctorate at the Institute of Development Studies at the University of Sussex.

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Before joining CAPPE, he was executive director of The Australia Institute, a progressive think tank he founded.

In an interview in The Age, he cited his biggest regret as: "Not studying philosophy at university. I now see that we do not really understand the things we believe until we examine the often-hidden philosophical assumptions that underpin them."

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