The Prince of Wales has warned global leaders that if we don’t tackle climate change in 18 months the human race will go extinct.

No, really. Here are his actual words, in a speech in London yesterday to foreign ministers from the Commonwealth.

I am firmly of the view that the next 18 months will decide our ability to keep climate change to survivable levels and to restore nature to the equilibrium we need for our survival.

OK. So assuming, for a moment, that the Prince of Wales isn’t just spouting gibberish, what kind of measures might we need to adopt in the next 18 months to “keep climate change to survivable levels”?

Happily, we have a good idea courtesy of Lord Deben, chairman of the government’s Climate Change Committee. Writing in the Prince of Wales’s favourite magazine Country Life, he says:

It simply demands that we live more sustainably – that we stop wasting water, become really energy efficient, cut food waste, eat 20 percent less meat, take all our energy from renewable sources and ensure our homes are properly insulated and ventilated.

That word “simply” is doing a lot of work there.

If you’re a carnivore like me, for example, you might not take too kindly to the notion that some dodgy peer who has made at least part of his fortune by promulgating green hysteria has the right to issue directives on how many bacon sarnies or burgers you can reasonably consume per week.

But I have an even bigger red flag waving over that glib suggestion that we should “take all our energy from renewable sources”.

All of it? Really??

The late Professor David Mackay, a Cambridge engineer and chief scientist at the UK government’s Department of Energy and Climate Change once looked at what decarbonising the economy by going 100 per cent renewable might look like for the British landscape. Needless to say, it wasn’t pretty.

It would involve:

Building 61,000 wind turbines. Covering 5 per cent of the UK landmass — the equivalent of Cambridgeshire, Gloucestershire, Lancashire, and Staffordshire combined — with solar arrays. (That would be 100 x more solar PV than his been installed in the whole world to date.) Damming most of the rivers in the West Highlands of Scotland to generate hydropower. Building huge barrages across rivers such as the Severn, destroying intertidal mud flats and devastating bird and fish species. Using the entirety of Britain’s agricultural land to grow biofuels.

David Mackay was by no means a climate change sceptic. But he was honest enough a scientist to be able to tell his government employers what they didn’t want to hear: that the idea that the UK could power itself by 100 per cent renewable energy was an “appalling delusion”.

Though it’s claimed that 14 per cent of the world’s energy is renewable, this is misleading. The majority of this — three quarters — comes from burning what is euphemistically called ‘biomass” — most of it what you and I call wood.

In other words the environmental movement is claiming as a triumph something that actually is a disaster: millions of people in the Third World are still reliant on the same inefficient, environmentally destructive, health-damaging energy technology that was used by cavemen.

As for wind turbines — ugly and seemingly ubiquitous a nuisance though they are — these currently provide less than one per cent of global energy.

Global energy demand, meanwhile, has been growing at about two per cent per year for the last 40 years. So, just to provide sufficient wind power to cover that increase in demand, how many wind turbines would need to be built?

Matt Ridley answers that question here:

If wind turbines were to supply all of that growth but no more, how many would need to be built each year? The answer is nearly 350,000, since a two-megawatt turbine can produce about 0.005 terawatt-hours per annum. That’s one-and-a-half times as many as have been built in the world since governments started pouring consumer funds into this so-called industry in the early 2000s. At a density of, very roughly, 50 acres per megawatt, typical for wind farms, that many turbines would require a land area [half the size of] the British Isles, including Ireland. Every year. If we kept this up for 50 years, we would have covered every square mile of a land area [half] the size of Russia with wind farms. Remember, this would be just to fulfil the new demand for energy, not to displace the vast existing supply of energy from fossil fuels, which currently supply 80 per cent of global energy needs.

Apart from the obvious visual blight, the environmental cost of building so many wind turbines would be enormous.

As Andrew Montford notes in a report for the Global Warming Policy Foundation called Green Killing Machines, nothing damages the environment quite like a wind farm.

The impact on bats is thought to be particularly serious, with turbines causing pressure waves that make their lungs implode. One recent study raised the possibility that whole populations of some bat species might be threatened. Birds, and particularly raptors, may collide with turbines: direct collision might cause 20 avian fatalities per turbine per year although considerably higher numbers have been mooted.

By coincidence, yesterday I found myself driving past the Prince of Wales’s country house near Tetbury in the Cotswolds, a strong competitor for the most beautiful area of England.

I drove through valley after valley of idyllic, unspoiled countryside, interrupted only by the occasional chocolate box village of honey-coloured stone with ducks and moorhens being photographed by Chinese tourists who clearly couldn’t believe somewhere quite so perfect-looking could actually exist.

This is the kind of place where you choose to live if, like the Prince of Wales, you are very, very rich. His net worth has been estimated at around $400 million — not unusual for a climate change alarmist.

From multimillionaire Leo Di Caprio to multimillionaire Al Gore, multimillionaire Sir David Attenborough to multimillionaire Tom Steyer, from multimillionaire Sir Richard Branson to multimillionaire Emma Thompson, environmentalism is a hugely attractive religion which enables you to achieve two perfectly wonderful things simultaneously.

First, it enables you to parade your moral virtue by showing that even though you are disgustingly rich you are still in fact an incredibly caring person.

Second, it means you can lecture the revolting lower orders on how they should live their lives and you can campaign to make everything more expensive and miserable for them, as Sir David Attenborough did earlier this week when he urged that air tickets should be hiked up. Obviously, people like Attenborough will go on flying regardless because they’ll still be able to afford it whatever environmental levies are imposed. But stopping other people from doing it will mean that airports and holiday destinations will be less crowded, just as Mother Gaia intended.

Anyway, as I drove through Prince of Wales country, marvelling at the deliciousness of the views, I wondered how many of the people living on the gorgeous private estates in which the Cotswolds abounds share Prince Charles’s views on the environment. Quite a few I suspect. I know of one super-rich hedge fund manager who has donated to Extinction Rebellion, for example, which strikes me as a classic example of the cognitive dissonance to which the super-rich seem prey. On the one hand they are clever enough and, presumably, capable of sufficient due diligence to have been able to have made vast fortunes; on the other, all their powers of discernment, intelligence and research appear to have left them when it comes to the issue of climate change.

How are we going to get it into their thick, overprivileged heads that the Net Zero carbon dioxide by 2050 targets for which they are so passionately advocating will destroy everything they hold dear?

They’ll only learn, I think, when they finally get what it is they’ve been asking for:

Piles of shredded raptors landing with a thud on the estates around Balmoral, sliced and diced by wind turbines. Solar farms and wind farms obliterating every last stretch of the Cotswolds. Wading birds driven forever out of the Severn Estuary by a tidal barrier. Their cleaning ladies, gardeners, and grooms turning up to work in tears because their parents have just frozen to death in fuel poverty.

They won’t like it. But by then it will be far too late.