Our house should have a stockade around it. As well as for the Jehovah’s Witnesses, free newspaper deliver boys, hawkers, Tory party canvassers, double glazing salesmen and marketing researchers it’s been declared off-limits for another unfortunate societal subgroup: the Green Party. This isn’t because I don’t like to see them, oh no. I find my little chats with these people quite entertaining, if not exactly edifying in any lasting way. Unfortunately they find them to be quite the opposite: educational but hardly entertaining.

Take, for example, my last exchange with the local Green Party representative. I’d just like to state at the outset that I’m not opposed at all to the idea of a clean, sustainable and diverse environment, quite the opposite. It’s just that, when I’m being asked to cast my precious vote, for which some of my ancestors fought and gave up their lives, I like to know exactly what it is that I am supporting and why. I like to acquaint myself with all the little details, the policy contraband, that other parties try to smuggle into their manifestos in the hope that we are too stupid or lazy to question their inclusion in the first place. Call me suspicious, but I’ve had too many people trying to pull a fast one on me in the past to accept anything at face value.

It was therefore with the ingenuous and trusting demeanour that we have come to associate with officers of Her Majesty’s Customs and Excise Division that the little man with glasses and sandals was greeted when he rang my doorbell. I asked him about his policies, and he told me, and it all seemed so reasonable and progressive until the contraband accidentally slipped out of the policy package: 'And we oppose animal experiments, of course'.

Of course. I mean, what else was I supposed to think? Now, I work in the pharmaceutical research sector where getting occasionally spat at, called a mindless barbarian and, for some, checking the underside of one’s car goes with the job. We are all, somehow, complicit in the murder and torture of hundreds of God’s creatures for greed and profit and therefore a justifiable target. I’d just come home from work having been detained as a result of a demonstration outside our gates. So, did I lay into him straight off, calling him an unthinking little Luddite? I’m very glad to say I didn’t. I listened very carefully to the view that all animals had rights too which should be respected. That they deserve equal treatment to human beings. That animal experiments simply don’t work. That you could do everything with cell cultures.

Then I laid into him, when I’d heard enough half-baked received opinions to fill my bin with thrice-recycled rubbish ten times over. I asked him exactly whether he would choose the life of a hundred thousand rats over the life of one human child, if that was the choice we faced? Whether it was acceptable to put down rat poison in tons and somehow not acceptable to test drugs on rodents? Whether pharmas would perform such expensive testing programs if they didn’t work? Whether he wanted to see armless children (or worse) walking around again? Whether he took drugs, and if he would be prepared not to take them if he knew how they were tested? How one could gauge the effectiveness of a beta-blocker (which I take) on the heart by testing it on a cell culture? I didn’t get any answers, at least none that were any way convincing.

My final question, however, was the most difficult for him to answer. What exactly did this policy detail have to do with protecting the environment? The issue of animal rights, whether you subscribe to it or not, is completely orthogonal to the issues of whether we grow up in a balanced environment, and often opposed to them. Would the Green Party sanction the cull of hedgehogs on a Scottish island if Mrs.Tiggywinkle’s kiddies had been wiping out rare birds? Perhaps, perhaps not, but going by what this spokesman said it’s difficult to tell.

Why this policy has been adopted is that the constituency of the green movement has changed, in that it now responds better to appeals to sentiment than to reason. Back in the days when I started university (over 20 years ago now) there was an Ecology movement, born out of a hard-headed and rigorous assessment of our hitherto environmental record. We were living beyond our means and if the balance slipped any further into the red then, as a race, we would end up environmentally bankrupt. The figures were plain to see and simple to comprehend. We were in a hole, and we hadn’t stopped digging. But the environmentalist movement then didn’t lose sight of its core objective, which was getting us back into the black. It was a simple but not simplistic approach, which maintained its focus on the problem by never losing sight of the real issues.

Of course, nothing changed. Well almost nothing: we still over fish, Americans still drive big cars and pay more for bottled water than for petrol, lions still face extinction, Amazonian rain forests still go up in smoke, water mains still lose 30% of their contents but now nobody takes a blind bit of notice of any jeremiad backed up by well-reasoned argument. Their pleas to reason falling on deaf ears, the Cassandras courted the cat-worshippers and tree-huggers instead of the scientists and pragmatists, who had long since returned to their labs and offices shaking their heads and bemoaning the myopic attitude of the human race.

So, to be 'green' is now to blindly accept New Age doctrines and crystal therapy, to oppose animal experimentation, to pull up GM crop trials designed to find out whether there are going to be any environmental effects at all. The outrage (rightly) felt by many of us used to be a starting point for developing the rather more productively pragmatic and consequence-based arguments of the first environmentalists. Now it has come to be seen as an end in itself and the justification for opposing rational actions taken by rational people. Take for example the Brent Spar debacle. The least environmentally harmful resolution to the problem of disposing of this oil platform was to dump it in the sea. But Greenpeace got involved, and of course, it ended up as the sort of argument where whoever shouted the loudest was bound to prevail. The platform eventually had to be dismembered and disposed of on land. This sort of emotional posturing helps no-one, and alienates those who are notionally sympathetic to the environmental movement, like me and even the former founder of Greenpeace, Dr. Patrick Moore.

From the perspective of the environmental demagogue, the roles of science, evidence and experience undermine the validity of the emotionally-based stance and are therefore to be destroyed if at all possible, to be discredited if not. The political has become redefined as the personal, pathologically so. It’s a confused, over-inclusive movement now, bereft of logic and dispassionate argument, dedicated to wallowing in a mishmash of half-baked beliefs, scare stories and pseudo-mystical garbage. Having abandoned its intellectual core, it appears now to people like me to serve as an umbrella for anyone who prefers opinion or superstition to reason. Well, it’s time to chuck out the tree-huggers and crystal therapists. It’s about time the movement became a lot less inclusive: when you mix together all the colours in the Rainbow, they don’t come out green but an icky brown.