The Constant Economy, By Zac Goldsmith

Truism though it may be, the significance of what is said can sometimes very much depend on who is saying it. The larger the figure, the weightier the pronouncement. Zac Goldsmith's new book is a case in point. A competent depiction of an alternative way of doing things, of a more benign and natural ordering of the global economy, is not in the normal course of events going to make a lot of noise; such volumes are produced and remaindered every year.

But if the author is the multi-millionaire son of Britain's most notorious buccaneering playboy, with the nation fascinated to see if he will turn out like his father, and if he happens to be blessed with angelic charm and the looks of a young Greek god, why then interviewers will beat a path to his door and the women among them will swoon in print.

How to separate Zac the thinker from Zac the man? Perhaps it cannot be done. The hold that his outlandish father Sir James Goldsmith had over the British imagination was too compelling, with his vast wealth, his years-long war with Private Eye and his aphorisms most of us would never be in a position to coin, such as "When you marry your mistress, you create a vacancy."

Now our obsession with celebrity means we are almost as fascinated by the son, both for the similarities – high-stakes poker player, first divorce looming at 34 – and also the differences. For Zac Goldsmith is a serious green, full-time environmentalist, former editor of The Ecologist, former deputy head of the Conservative party's green policy review, and we wouldn't be human if we didn't think, is it all for show? When will the paternal genes kick in?

Yet the surprising thing for anyone who meets Goldsmith and talks to him at length is the depth of his knowledge of environmental problems and his fluency in discussing them. You can fake passion, at a pinch; you can't fake the sort of detailed policy expertise Goldsmith junior possesses, and is on display in this new book.

The Constant Economy is an attempt to sketch out how a different sort of society, in tune with the limits of the earth, really can be built through practical measures within the current political system. Not a Utopia; not some deep green vision of living on lentils in a tepee.

Goldsmith is saying, we can truly make a difference with some legislation here, some new emphasis there, perhaps some tax shifting somewhere else. He sets out his ideas in extensive detail in ten sections ranging from how we can measure human well-being differently and how we can extend democracy, to how we can transform the way we produce food, create energy and organise transport. It's well done, and some of the illustrative fact is fascinating, but it isn't mould-breaking like Schumacher's Small Is Beautiful, say.

Perhaps the most striking aspect of the book is its timing, fortuitous on several levels. The run-up to the great Copenhagen climate conference in December has just begun: the whole world will be focusing on the environment in the coming months. The recession seems to be ending; what better time to offer an alternative economic model to the one which so spectacularly crashed? Most of all, this Parliament is drawing to a close, and by next May we will see a general election which will probably sweep the Tories to power.

And there's the rub. For Goldsmith is also the Conservative prospective parliamentary candidate for Richmond Park, a seat he has a good chance of winning, and here he is displaying an encyclopaedic knowledge of the environment, its problems and their potential solutions that no Conservative shadow minister could match.

In anyone else this would seem like a job application to David Cameron, pure and simple. But it isn't simple with Zac Goldsmith. Some of the book's radical standpoints – no nuclear power, for instance – mark him out as a potential rebel in government, and a danger to employ. Perhaps the book is most truly seen as the personal manifesto of a man moving out of the giant shadow of his father, even if we watch fascinated to see if he will eventually embrace it.