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Britain’s Met Office Welcomes Audit By Australian Researcher About HadCRUT Errors

Graham Lloyd, The Australian

Britain’s Met Office has welcomed an audit from Australian researcher John McLean that claims to have identified serious errors in its HadCRUT global temperature record.

The audit said the HadCRUT temperature record, the main global temperature set used by climate models, showed exaggerated warming and was not fit for global studies.

“The HadCRUT dataset is being constantly updated and improved to provide ever greater certainty on changes in global climate”, a Met office spokesman told The Australian. “Any actual errors identified will be dealt with in the next major update.’’

Dr McLean’s audit found data prior to 1950 suffered from poor coverage and very likely multiple incorrect adjustments of station data.

Data since that year had better coverage but still had the problem of data adjustments, Dr McLean said.

Anomalies identified in the McLean paper include at St Kitts in the Caribbean, the average temperature for December 1981 was zero degrees, normally it’s 26C.

For three months in 1978 one place in Colombia reported an 82 degrees Celsius average — hotter than the hottest day on Earth.

In Romania one September the average temperature was reported as minus 46°C.

Sometimes ships would report ocean temperatures from places up to 100km inland.

The Met Office said automated quality checks were performed on the ocean data and monthly updates to the land data were subjected to a computer assisted manual quality control process.

“The HadCRUT dataset includes comprehensive uncertainty estimates in its estimates of global temperature,” the Met Office spokesman said.

“We previously acknowledged receipt of Dr John McLean’s 2016 report to us which dealt with the format of some ocean data files.

“We corrected the errors he then identified to us,” the Met Office spokesman said. Dr McLean is an IT specialist who has been extracting and analysing climate data since 2004.

He was an Expert Reviewer of the IPCC’s 2013 Climate Assessment Report and is the author of four peer-reviewed papers on climate matters.

He was awarded his PhD by James Cook University, in December 2017 after his PhD on problems with climate data recorded data had been externally examined.

The Met Office said many of the problems identified are well known to anyone who has worked with climate data and are dealt with extensively in the literature including in the papers describing the construction of the data sets.

“The HadCRUT data set stretches back to 1850 and it contains over 7 million points of data from in excess of 7500 observation stations on land around the globe together with millions of measurements of sea-surface temperature”, the Met Office spokesman said.

He said the small number of specific errors highlighted represent a tiny fraction of the data and as such were likely to have a negligible impact on the overall results.

“The long-term increase in global temperature is unequivocal,” the spokesman said.

“This is backed up by other globally recognised datasets, all of which are run independently, and find very similar warming,” he said.

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