The first ever audit of the world’s most important temperature data set has found it to be so riddled with errors that it is effectively useless.

HadCRUT4 is the primary dataset used by the Intergovernmental Panel on Climate Change (IPCC) to make its dramatic claims about “man-made global warming”, to justify its demands for trillions of dollars to be spent on “combating climate change” and as the basis for the Paris Climate Accord.

But according to a groundbreaking analysis by Australian researcher John McLean it’s far too sloppy to be taken seriously even by climate scientists, let alone a body as influential as the IPCC or by the governments of the world.

“It’s very careless and amateur,” he says. “About the standard of a first-year university student.”

Among the many errors found by McLean were:

Large gaps where there is no data and where instead averages were calculated from next to no information. For two years, the temperatures over land in the Southern Hemisphere were estimated from just one site in Indonesia.

Almost no quality control, with misspelled country names (‘Venezuala” “Hawaai” “Republic of K” (aka South Korea) and sloppy, obviously inaccurate entries.

Adjustments – “I wouldn’t be surprised to find that more than 50 percent of adjustments were incorrect,” says McLean – which artificially cool earlier temperatures and warm later ones, giving an exaggerated impression of the rate of global warming.

Methodology so inconsistent that measurements didn’t even have a reliable policy on variables like Daylight Saving Time.

Sea measurements, supposedly from ships, but mistakenly logged up to 50 miles inland.

A Caribbean island – St Kitts – where the temperature was recorded at 0 degrees C for a whole month, on two occasions (somewhat implausibly for the tropics)

A town in Romania which in September 1953, allegedly experienced a month where the average temperature dropped to minus 46 degrees C (when the typical average for that month is 10 degrees C).

Yet this is the temperature record from which the IPCC has formed its judgement that the “global warming” since the mid-19th century is sufficiently alarming for governments around the world to have to take urgent action, which is currently costing taxpayers around $2 trillion per annum.

The HadCRUT4 dataset is a joint production of the UK Met Office’s Hadley Centre and the Climatic Research Unit (of Climategate notoriety) at the University of East Anglia.

According to McLean:

“It seems like neither organization properly checked the land or sea temperature data before using it in the HadCRUT4 dataset. If it had been checked then the CRU might have queried the more obvious errors in data supplied by different countries. The Hadley Centre might also have found some of the inconsistencies in the sea surface temperature data, along with errors that it created itself when it copied data from the hand-written logs of some Royal Navy ships.”

McLean’s report could scarcely have come at a more embarrassing time for the IPCC. On Monday, it will release its 2018 Summary for Policy Makers claiming that the global warming crisis is more urgent than ever. But what McLean’s audit strongly suggests is that these claims are based on data that simply cannot be trusted.

Though the IPCC uses three main surface temperature datasets – the others are compiled in the U.S. by NASA and NOAA – the UK-based HadCRUT is its preferred one for historical reasons: the founder of the Hadley Centre (where HadCRUT is partly produced) was Sir John Houghton, who also happened to be co-chairman of the Working Group 1 of IPCC and was editor of its first report.

So the fact that the IPCC’s primary dataset has been shown up as shoddy, unreliable and amateurish is not helpful to the IPCC’s credibility.

As McLean says:

“Governments have had 25 years to check the data on which they’ve been spending billions of dollars. And they haven’t done so once.”

McLean is the Australian IT analyst who broke another scandal about the global warming scare: that it was effectively the creation of just 53 people.

He reached this figure by analysing the IPCC’s 2007 Assessment Report, which, according to the IPCC, represented a “consensus” of the views of “2500 climate scientists”.

But in fact the number of scientists involved in the key Chapter 9 – the one which reached the headline conclusion that human-induced warming was detectable in every continent except Antarctica, and that this was leading to all manner of disasters from melting glaciers and sea ice to changing rainfall patterns and more intense cyclone activity – was just 53.

Furthermore – as Christopher Booker reported in his The Real Global Warming Disaster – these 53 authors mostly belonged to a close professional network, intimately bound with Michael Mann’s “hockey stick”. Not so much a “consensus” then. More – as the subsequent Climategate scandal confirmed – a cabal of vested interests.

McLean’s audit on the failings of HadCRUT is available here from the website Robert Boyle Publishing. It costs US $8 which may provide some recompense for his unpaid work, conducted as an extension of his PhD thesis, supervised at James Cook University by Peter Ridd.

Ridd is the professor who was hounded out of his job after telling the truth about the Great Barrier Reef: that it wasn’t being destroyed by “global warming.” Since this didn’t accord with the narrative being promoted by his alarmist institution he was fired on the pretext that he had “engaged in a pattern of conduct that misrepresents the nature and conduct of the disciplinary process through publi­cations online and in the media”.

Such are the inaccuracies in the data record, McLean believes, that it is impossible to know how much global temperatures have really risen.

But he estimates that of the 0.6 degrees C that the planet has warmed since 1950, perhaps one third has been exaggerated.

So the real figure, he estimates, is a warming of 0.4 degrees C in the last seven decades.

“Most people can’t even notice a change in temperature of 1 degree C for one moment to the next. So the idea that governments are spending so much money on the basis of a rise in temperature a fraction of that spread over almost 70 years is just idiotic beyond belief.”

The Hadley Centre and Met Office will find it difficult to dismiss McLean as a crank. In March 2016, he advised them of certain errors which they promptly corrected. So he’s an authority they take seriously.