Written by Christopher Booker
Scarcely a day goes by without a supposed expert advising us of the latest step we must take to save the world from a global warming apocalypse. But this week's proposal from Lord Stern of Brentford out-trumps them all.
A former civil service economist plucked from semi-obscurity by Tony Blair to become a guru on 'climate change', he now tells us the best way to stave off global warming is to give up eating meat.This, he explains, is because one of the most damaging contributions to the greenhouse effect is the methane given off by all those cows and sheep when they pass wind.
Even by the Green lobby's standards of self-deceiving absurdity, this must be a front-runner for the most fatuous proposal so far. Yet Lord Stern, alas, is not the first anti-global warming zealot to issue such an absurd missive.
Last year, Dr Rajendra Pachauri, the railway engineer who is head of the UN's Intergovernmental Panel on Climate Change, made a similar suggestion to a conference organised by Compassion in World Farming.
As a Hindu vegetarian, it might be understandable that Dr Pachauri should want the rest of us to give up eating meat - though he conveniently didn't mention the 400 million sacred cows in his native India, which pass wind just as often as the cattle in the fields of carnivorous Britain.
Earlier this year, even the NHS came up with the idea that hospitals should stop serving meat to patients, because 'unless we take effective action now, millions of people round the world will suffer hunger, water shortages and coastal flooding as the climate changes'.
Yet the simple fact is that the claims of all these veg-obsessives don't stand up to scientific scrutiny. They aren't even based on real statistics.
Take Lord Stern's assertions that meat-eating is responsible In fact, according to official figures, all the world's agriculture put together is responsible for only 14 per cent of global greenhouse gas emissions - and a large part of that comes from rice-growing in countries such as China and India.
Indeed, even if we slaughtered every cow and sheep in the world and then ate nothing but fruit and veg, the resulting cut in greenhouse gas emissions would be infinitely smaller than the imaginary figure claimed by Lord Stern.
Even if it were higher, it would soon be outweighed by fast-rising emissions from other sources, such as the heavily polluting coal-fired power stations being built by China at a rate of nearly two a week.
There is also the problem of what such a proposal would cost us.
Those who rely on the dairy or livestock industries for employment would be ruined. There would be no wool or leather and, without natural fertiliser provided by sheep and cattle, the land would suffer, too.
Livestock farming is not some unnecessary consumer indulgence. When properly managed, it is a vital part of the natural cycle of the land.
But this is not the first time Lord Stern has been fingered for using questionable figures.
When, in 2006, he published his enormous report on what the world should do about climate change, he claimed that some of his projections were based on the work of a genuinely eminent economist, Dr Richard Tol, author of the UN's official handbook on how to measure the impact of global warming.
Dr Tol, however, was so angered by the way Stern's report had misused his methods to exaggerate the dangers of global warming that he put out a statement describing the more lurid predictions as 'preposterous'.
In truth, Stern's vegetarian proposal is simply the latest in a list of measures we are told will protect us from the warming menace; a list that grows longer and more moronic by the day.
We have been told we must cover Britain with giant windmills, all drive electric cars and look forward to paying a £3,500 tax every time we buy a new vehicle.
When each of these Quixotic proposals is examined, however, it turns out to be dottier than the one before.
The 2,300 wind turbines we have already built in Britain generate so little electricity that the average output of all of them put together is less than that of a single, medium-sized, conventional power station.
Similarly, what the politicians never explain about electric cars, which can travel only 50 miles or so before their batteries need recharging, is that the electricity to power them comes from the national grid - largely fed by carbon-emitting fossil fuels.
And the soaring 'green taxes' we must all pay for travelling by car or plane - like our rising energy bills - may help make us ever poorer, but will make not the slightest difference to the heating of the planet.
Why do they persist with such illogical and flawed suggestions to 'save the planet'?
Well, the real reason why Lord Stern and so many other luminaries are coming up with ever wilder comments on global warming is that they are all getting desperately worried about the outcome of the world conference on climate change, to be staged in Copenhagen in less than six weeks.
This was why Gordon Brown was warning last week that we have 'less than 50 days' to save the planet.
However, he knows, as they all do, that the prospects of any meaningful treaty coming out of Copenhagen are virtually zero - not least because such fast-developing major players as India and China refuse to cut their carbon emissions unless they are paid hundreds of billions of dollars by the West
So how on earth did we end up in this ridiculous muddle?
This week, I publish a book that tells the bizarre story of how all this has come about - beginning 25 years ago, when a small number of scientists first observed that levels of CO2 and temperatures were rising.
The book shows how, with the aid of carefully programmed computer models, this observation was manipulated into one of the greatest scare stories of all time.
With remarkable speed, it won the support of many of the world's politicians, led by Al Gore and the EU.
For the first two decades, it seemed that the scientists were right - CO2 levels and temperatures continued to rise together, just as the computer models had predicted they would. But in the past few years, three things have happened that threaten to change the plot dramatically.
The first is that, while CO2 levels have continued to rise, temperatures have failed to follow suit, showing that the models are hopelessly wrong.
Second, more and more scientists, some eminent, have been arguing that the official theory behind those models is fundamentally flawed.
They claim that the real causes of climate change are not man-made, but natural.
And third, we are beginning to see the mind-boggling cost of all those planet- saving measures that the politicians want to impose on us.
Indeed, we are fast approaching the crunch point, when a large part of the world must decide whether it is prepared to commit what would amount to economic suicide to tackle a crisis many scientists argue has never really existed.
So rather than debating whether we should be turning vegetarian, shouldn't we all be asking the bigger question: how have we let the Green lobby's obsession with climate change become the most costly scientific blunder in history?
And then go out and celebrate the Copenhagen summit with a nice juicy steak.