The writer is England’s the Viscount (Christopher) Monckton of Brenchley.

WHILE the Gillard government’s climate-change parliamentary committee plots to wreck Australia’s economy with a rigged market to make motoring and electricity unaffordable as soon as the new Greens-infected Senate starts work in July, thoughtful pollies are at last – privately, quietly – beginning to ask the Gershwin question.

What if it ain’t necessarily so? Suppose there’s no climate crisis?

There has been a gain in Antarctic sea ice since 1979 that almost matches the loss in Arctic sea ice. Source: AFP

The Romans used to farm out tax collection to “tax farmers” such as St Matthew. The cap-and-tax boondoggle is a tax-farming scam to impoverish the working man and enrich the new tax farmers: bankers, traders, ministers, officials and media moguls. None of them saints.

Cap-and-tax in Europe has been a wickedly costly fiasco. The rigged market has collapsed twice. Member states cheated by allowing themselves more rights to emit than their actual emissions, so the price of emission rights plummeted. Then the tax farmers simply invented 90 per cent of their carbon trades.

Result: electricity prices have doubled. In the name of preventing global warming, many Britons are dying because they cannot afford to heat their homes.

Cap and tax is as pointless as it is cruel. Australia accounts for 1.5 per cent of global carbon emissions. So if it cut its emissions, the warming forestalled would be infinitesimal.

It’s worth explaining exactly why. Suppose the Australian committee’s aim is to cut emissions by 20 per cent by 2050. Anything more ambitious would shut Australia down, especially while the Greens insist on not letting the country use its own zero-carbon-emitting uranium as fuel.

A 20 per cent cut by 2050 is an average 10 per cent cut from now until then. Carbon dioxide concentration by 2050 probably won’t exceed 506 parts per million by volume, from which we deduct today’s concentration of 390 ppmv. So humankind might add 116 ppmv from now until then.

The CO2 concentration increase forestalled by 40 years of cap-and-tax in Australia would be 10 per cent of 1.5 per cent of that 116 ppmv, or just 0.174 ppmv. So in 2050 CO2 concentration would be – tell it not in Gath and Ashkelon – 505.826 ppmv, not 506.

Thus what we maths wonks call the proportionate change in CO2 concentration if the committee got its way would be 505.826 divided by 506, or 0.9997. The UN says warming or cooling, in Celsius degrees, is 3.7 to 5.7 times the logarithm of the proportionate change.

It expects only 57 per cent of manmade warming to occur by 2100: the rest would happen slowly and harmlessly across 1000-3000 years.

To be charitable to the committee, let us take the UN’s high-end estimate. The warming forestalled by cutting Australia’s emissions would be very unlikely to exceed 57 per cent of 5.7 times the logarithm of 0.9997: that is – wait for it – a dizzying one-thousandth of a degree by 2050.

I have set out this calculation to show how certainly it is known that all attempts to cut CO2 emissions will expensively fail. Focused adaptation to any adverse consequences of such warming as may occur would be orders of magnitude more cost-effective. But do we need to cut CO2 at all? Some cold facts:

Satellite datasets show last year was not the warmest on record. It was not the least snow-covered year but the most snow-covered: a largely unreported gain in Antarctic sea ice since 1979 almost matches the widely reported loss of Arctic sea ice.

It was not the worst year for hurricanes, but the best year: the accumulated-cyclone-energy index shows less tropical-cyclone activity worldwide than for 30 years.

The forest fires in Russia and southern Australia, and the floods in Pakistan and eastern Australia, were far from the worst ever. Nor can they be attributed to human influence: the UN’s climate panel has warned us against that.

They were caused by naturally occurring weather patterns called blocking highs. And global warming can scarcely be blamed after a decade without any.

Nor did 2010 see the second-highest level of natural catastrophes. Yes, 90 per cent of them were weather-related, but in most years that is true, and was true long before we could have influenced climate.

Nor is sea level rising fast. It has risen at the rate of just 0.3m a century since satellites measured it reliably in 1993, under a quarter of the average rate during the past 11,400 years. The Greens don’t believe their own whining about sea level: their Hobart office is just metres from the “dangerously” rising ocean.

Nor do most scientists believe man-made global warming will be catastrophic. Most are not climate scientists and take no view, and only a few climatologists have published on the central question how much warming there will be.

Of these, the researchers using measurement and observation rather than modelling have shown that much of the radiation the models say should be warming the surface is escaping to space as before.

The upper air in the tropics that the models predict should warm at thrice the surface rate is warming only at the same rate; model-predicted surface evaporation in response to warming is a third of the observed rate.

The missing heat energy imagined by the models but not present as warming in the past decade is not lurking in the oceans; and the entire warming of the late 20th century can easily be explained without blaming man.

Just one of these fatal discrepancies between prediction and reality – and each points to very little future warming – would normally be enough to dismiss climate catastrophism.

As the Gershwins rightly concluded, “It ain’t nessa, ain’t nessa, ain’t nessa, ain’t nessa, ain’t necessarily so.”

Republished in The Australian newspaper, 22 Jan 2011