There are two kinds of people in the world, as an old joke has it: those who think there are two kinds of people in the world, and those who realise there aren't. The philosopher Roger Scruton belongs to the first set. Over the past 30 years he has created a role for himself as a champion of traditional English conservatism, placing himself in one corner along with other admirers of fox-hunting, village greens and parish churches. In the other he sees hordes of chavs and Guardian-reading prigs  health-and-safety fundamentalists, postmodern relativists, entitlement freaks, utilitarians, multiculturalists, socialists, aging soixante-huitards, nihilist revolutionaries and political correctionists gone mad.

But if you think Scruton can be dismissed as a churlish little-Englander you're in for a big surprise. Read his books without prejudice and you will find him lucid and informative, companionable, learned and urbane. He is probably better-read than you, in more languages than you know, and he can take on experts in legal history, economic theory, music, art, architecture, wine and world literature without missing a beat. There seems to be only one thing he cannot do, and that is ambiguity. His constant refrain is: "Which side are you on? Will you stand by the gnarled oak of Englishness or will you bring on the bulldozers of soulless modernity? Can you appreciate beauty or are you an enraged devotee of contemporary art? Do you want wholesome food or tasteless, shrink-wrapped crap? Do you care about western civilisation or would you be happy to see it demolished? Are you one of us or one of them?"

Those who dwell in the valleys of uncertainty are liable to feel bullied by Scruton's methods. If we value the kind of authors who are hard to pin down  Rousseau, say, or Marx, Mill or Derrida  we will wish he was not so eager to deride them. No one can be right all the time, after all, and none of us is immune to life's ironies. Even if we agree with Scruton that many of the horrors of the past century are due to leftist authoritarianism, we might want to jog his memory about the NHS and other achievements of social democracy, and remind him that totalitarianism has right-wing forms as well. But as I said, he is one of the best philosophers of our time.

In his new book Scruton turns his attention to ecological issues: erosion of habitats, depletion of resources, accumulation of waste and, of course, climate change. He's not a catastrophist, but he's not a sceptic either, and he recognises that the future of our natural environment poses theoretical problems as well as practical ones. The familiar backstops of political discussion  notions such as individual freedom, social equality, national sovereignty, representative democracy or human rights  are not going to help us face the fact that if we carry on as we are, the entire planet may soon become uninhabitable. You could in fact see old-style politics as the root of the problem: a vast filibuster that keeps the interests of unborn generations off the agenda, not to mention the fate of other species and the biosphere as a whole.

If the standard routines of political thought prevent us from confronting the dangers that threaten our planet, we might conclude that it is time to abandon the old stand-off between rightists who want to cling to the past and leftists planning a brave new world. But Scruton will not see it that way. If environmental disaster is the question, he thinks, then leftism is still "the worst thing that can happen", and conservatism the only answer. He knows that conservatism has got itself a bad name by flirting with unbridled capitalism and promoting the idea that there's no motive like the profit motive. But that's never been Scruton's version, and for the past few years he has been conducting a grand exercise in rebranding. He still divides the world into shrewd conservatives and leftist buffoons, but in the new terminology his sort of people are now "oikophiles" (from the Greek "oiko" for house, which is the derivation of "eco"), while the rest of us are benighted "oikophobes".

The English have a word for it too: home-lovers, as opposed to home-haters. I'm not sure why Scruton resorts to Greek, but up to a point I can see what he means. I got through Green Philosophy sitting by an open fire in the old stone cottage where I have lived most of my life, and I can understand why oikophiles such as me might be well-attuned to environmental issues. We like to think of ourselves not as lords and masters of our private patch, but trustees of a heritage that we hope to pass on to successors who will cherish it as we do. On the other hand I cannot get my mind round the idea of oikophobia. The great wanderers of myth and history, from Oedipus to Wotan, from Borrow and Stevenson to Davies and Kerouac, may not have been amiable oikophiles, but they did not have a sinister plan to replace homely hearths with parallelograms of paupers. And if you are homeless, or hate the place where you live, the chances are that you are not suffering from oikophobia, but drifting into oikophilic melancholia, dreaming of the cherishable home you have not got.

The distinction between oikophiles and oikophobes may not hold water, but it gives Scruton a launch-pad for some effective polemics. He is acute about the so-called "precautionary principle", pointing to the dangers of disaggregating the innumerable risks that face us and trying to pick them off one by one. He also reminds us that NGOs are not angels, and that some of them have the wealth and power of governments, without any of the accountability. But then he does not like governments either, and enjoys setting off alarms about faceless bureaucrats and the nanny state  though if he really thinks that schools no longer organise adventure-trips, or that fruit and vegetables cannot be sold unwrapped, he needs to stop reading the red-tops and get out a bit more.

The damage we do to our environment arises mainly from what economists call externalities: side-effects that can be disowned by the people who cause them. Scruton believes that many ecological externalities  river pollution, for example  can be sorted by a combination of free markets and common law. Beyond that, he appeals to the idea  borrowed without acknowledgement from the socialist historian EP Thompson  of a "moral economy", meaning standards of acceptable behaviour that are espoused by ordinary people. Thompson used the notion to rescue 18th-century rioters from the condescension of the right, but in Scruton's lexicon it describes the values promoted by the Women's Institute, National Trust and Campaign for the Protection of Rural England in their struggles with polluters and property developers. On any normal definition, these institutions belong in the same category as the NGOs that Scruton abhors, but he circumvents the difficulty by calling them "civil associations", on the not-un-question-begging ground that they have a different "moral character".

When it comes to environmental dangers that are too big to be dealt with by NGOs or civil associations, Scruton displays a boyish confidence in the prospect of a technical fix. His aversion to international organisations limits his options, and his hatred of state power cramps him further, but he ends up calling for government-funded research into carbon capture and solar energy, and argues that Washington ought to get into the business of geo-engineering  solar radiation management perhaps, or ocean fertilisation  without waiting for the consent of other countries. If you are wondering how these proposals can be squared with Scruton's lofty objections to state intervention as such, do not worry: with a wave of his rhetorical wand he transforms the faceless nannies of legend into kindly patriots shouldering their inherited responsibility for the homeland that they love.

Perhaps the idea of externalities could be extended from economics to philosophy, to describe by-products of the argumentative process for which other people are expected to pick up the tab. By the end of his book, Scruton is clearly involved in the same sorts of intellectual make-do-and-mend as the rest of us, but he tries to dump all the inconsistencies on the trusty old fall-guy that is the loony left. He might be even wiser if he were less interested in ideological purity  as he acknowledges, with characteristic grace, by giving his dateline as "Scrutopia".

Jonathan Rée co-edited The Concise Encyclopaedia of Western Philosophy and Philosophers (Routledge).