Of all the blithering nonsense climate deniers throw at the environmental movement, there is perhaps one criticism that does real damage – that "green is the new religion".

We can handle the scientifically illiterate and ethically questionable attempts to undermine evidence of climatic change using cherry-picked data and discredited theories, just as we can counter the increasingly futile attempts to question the importance of the green economy and the efficacy of clean technologies. The scientific evidence linking greenhouse gas emissions and potentially dangerous levels of climate change is now so well proven, and the physical demonstration of effective clean technologies so prevalent, that the guileless smears attempted by self-styled "climate sceptics" lack their former sting.

They are fighting a losing battle with science and evidence, hence the increasingly vocal suggestion that green is the new religion. This line of attack is hugely effective and highly damaging for three main reasons.

Firstly, and most importantly, if you can convince people to see environmentalism as a religion, then you move green issues from the field of science and data into the field of theology and belief.

Religion can mean a "pursuit or interest followed with great devotion" – a definition which could just about allow environmentalism to be classified as a "religion". But it is more commonly defined as "the belief in and worship of a superhuman controlling power, especially a personal God or gods", or "a particular system of faith and worship". Equate "greens" with this type of religion, with faith and deities, adherence and heresy, and it becomes all but impossible to prove or disprove the central tenets of environmentalism.

"Climate change is a matter of faith," say the climate sceptics, "green actions are acts of religion – they have no place in the real world of politics and business." Frustratingly, you can argue against this accusation all you like, but any response is tainted in the eyes of your critics by the fact it is made with a "religious conviction" that will brook no argument.

Secondly, this trope is doubly clever because like all good smears it draws on the weaknesses of its target. Some environmentalists are occasionally guilty of the worst excesses of religion. There is a tendency to drown out legitimate criticism in the most forceful terms, an inclination towards proselytization that can alienate many people, and an occasional willingness to cling to sacred cows even when the scientific evidence suggests we should at least discuss their being slayed (I'm thinking nuclear power and GM as prime examples). The image of environmental campaigners filled with passionate, but not religious, conviction makes the suggestion that environmentalism has become a religion look convincing.

Thirdly, if you can convince people that green is a religion then you allow anyone who disagrees with environmental policies or business models to wrap themselves in the comforting blanket of heresy. You create a powerful narrative of brave resistance which appeals to iconoclasts, rationalists, and sceptics (in the true sense of the world) everywhere.

All of which brings me, somewhat circuitously to the Guardian and Simon Hoggart's second assertion in as many weeks that wind turbines are like church spires, in that "they achieve nothing but have a purely religious significance" – an argument that was expounded by drawing on James Lovelock's recent claims that environmentalism has become a religion.

"He's right," Hoggart wrote of Lovelock's latest comments. "[Environmentalists] accuse their opponents not just of being mistaken, but of heresy. They put too much importance on symbolic acts; just as your marrow at the harvest festival doesn't end world hunger, so you won't save the planet by cycling to work. Wind turbines, like spires, reach for the skies to no apparent effect. Facts that contradict dogma have to be concealed, as in the East Anglia data hush-up. Allies who change their minds can be denounced as apostates."

Now Simon Hoggart is one of the best and most respected journalists working in Britain today, but, like his stable-mate at the Guardian, Simon Jenkins, he has decided wind turbines are loathsome and that anything to do with climate change and environmentalism should face the same cynicism that serves his peerless political sketch-writing so well.

As such, Hoggart can argue greens have been captured by "religious fervour", wind turbines serve no purpose beyond the symbolic, the only take away from the University of East Anglia affair was the ludicrous assertion that data was "hushed-up", and one of the UK's most intelligent journalists is happy to declare that "I have no idea who is right about climate change".

Without wishing to accuse Hoggart or many of the other commentators who have made similar points in recent years of heresy, this is all utterly nonsensical.

Environmentalism is not a religion in any real sense of the word. Yes, some of its supporters display levels of conviction that can look religious, but the central tenets of environmentalism, not to mention green policies and campaigns, are based on evidence and the application of scientific reason.

We might sometimes disagree on the evidence and the conclusions, but no one is using faith as an argument to advance their case. Those who do are quickly discredited and are increasingly confined to the more "out there" extremes of the environmental movement.

I'm sure Hoggart is being truthful when he says he does not know who is right about climate change, but if he wanted to apply the same standards of knowledge to other areas he would have to admit he is not sure who is right about the link between smoking and cancer – the medical establishment, or the discredited hacks who spent years providing dodgy research to the tobacco companies. He can argue that wind turbines look ugly, but to argue that they have "no apparent effect" is to dismiss reams of independent evidence to the contrary, not least the energy meters attached to any wind turbine recording the power being fed into the grid.

People who suggest climate change might not be happening are not heretics, but they are guilty of a quite staggering lack of intellectual rigour and those who suggest green is a religion, including the estimable James Lovelock, are guilty of a remarkable category error.

You can call environmentalism an ideology, a political movement, even a lifestyle; but it sure as hell isn't a religion.

James Murray is the editor of BusinessGreen