Two reports bearing on climate change have been published in the last few days. The first is from the Inter-Governmental Panel on Climate Change (IPCC), and is full of forebodings about the future of the planet. This one is a Special Report on the implications of global warming above 1.5 degrees C. There are more of these special reports to come. The basic point or take-home message seems to be that limiting warming to 1.5 C is better for everyone than allowing warming to grow to 2.0C. No matter that both the 1.5C and 2.0C ‘boundaries’ seem to have been pulled from the air, being based on model projections if on anything at all. There are many confident assertions in the report, and some of them, such as we are already seeing human-induced extreme weather as a result of global warming, do not seem well supported, if at all. However, it is standard IPCC stuff.
It got a blast of TV and advertising support. The ABC trumpeted it as first-news story on one night, but never referred to it again, at least on my radio. Most British newspapers didn’t refer to it at all, apparently. It is hard not to feel that the air has gone out of the global warming balloon. There have been too many dire warnings, too many predictions that were way out of sense, too many people have said we had only so many days to save the planet and so on. People have stopped listening. There is a life to live. Temperatures seem to go up and down. If the long-term trend is a little on the warming side, why is that not a good thing? Well, the IPCC have the answers, they think, but no one is buying them. For those who need more persuasion, the UN survey of what people think are real issues that trouble them puts climate change, however described, pretty low in the list (16th), at about an average six per cent across the globe.
Our Government gave a characteristically muddled response, and said nothing more. My general response is that there is virtually no likelihood at all that anything will be done to ensure that warming doesn’t pass 1.5C in any conceivable time, so we had better get used to the notion that we in Australia adapt to floods, fires and droughts a bit better than we have done in the past.
In the meantime Dr John McLean has published an ebook that shreds the basic temperature data on which the IPCC relies. This is a dataset known as HadCRUT4. Dr McLean made the investigation of this dataset the central theme of his PhD thesis at James Cook University, which went through examination, and was passed. So it has academic status. I first met the author some ten years ago, when I had given my ‘Cool Look at Global Warming’ speech and produced the later article.
The first doubt I had about the global warming thesis was the reliance on what seemed to me the most rubbery temperature data. “It’s much worse than you think,’ he said to me, and gave examples. In the past decade we have met again a couple of times and corresponded. I admire his persistence and capacity for hard work, and I think there is no doubt that he is right — and who am I to contradict his examiners? His work makes the new SR paper of the IPCC highly suspect, and in fact the whole litany of IPCC anxieties. If we cannot be sure about the basic data, how sure can we be that the prophecies have any value?
I have purchased my own copy of the book, which costs $US8. Those interested should go to John McLean, An Audit of the Creation and Content of the HadCRUT4 temperature Dataset, and buy the book through the publisher, Robert Boyle. In my view the book provides a sharp sword that should be taken to all the predictions and projections of the various IPCC reports. Dr McLean was an expert reviewer for the Third Assessment Report, and pointed out a lot of problems with the dataset then. He was astonished to find that no audit of any kind had been undertaken of the basic data, and that led to his own thorough-going investigation.
What follows is from the Executive Summary. I think the final sentence says it all.
…As far as can be ascertained, this is the first audit of the HadCRUT4 dataset, the main temperature dataset used in climate assessment reports from the Intergovernmental Panel on Climate Change (IPCC). Governments and the United Nations Framework Convention on Climate Change (UNFCCC) rely heavily on the IPCC reports so ultimately the temperature data needs to be accurate and reliable.
This audit shows that it is neither of those things. More than 70 issues are identified, covering the entire process from the measurement of temperatures to the dataset’s creation, to data derived from it (such as averages) and to its eventual publication. The findings (shown in consolidated form Appendix 6) even include simple issues of obviously erroneous data, glossed-over sparsity of data, significant but questionable assumptions and temperature data that has been incorrectly adjusted in a way that exaggerates warming.
It finds, for example, an observation station reporting average monthly temperatures above 80°C, two instances of a station in the Caribbean reporting December average temperatures of 0°C and a Romanian station reporting a September average temperature of -45°C when the typical average in that month is 10°C. On top of that, some ships that measured sea temperatures reported their locations as more than 80km inland.
It appears that the suppliers of the land and sea temperature data failed to check for basic errors and the people who create the HadCRUT dataset didn’t find them and raise questions either.
The processing that creates the dataset does remove some errors but it uses a threshold set from two values calculated from part of the data but errors weren’t removed from that part before the two values were calculated.
Data sparsity is a real problem. The dataset starts in 1850 but for just over two years at the start of the record the only land-based data for the entire Southern Hemisphere came from a single observation station in Indonesia. At the end of five years just three stations reported data in that hemisphere. Global averages are calculated from the averages for each of the two hemispheres, so these few stations have a large influence on what’s supposedly “global”.
Related to the amount of data is the percentage of the world (or hemisphere) that the data covers. According to the method of calculating coverage for the dataset, 50% global coverage wasn’t reached until 1906 and 50% of the Southern Hemisphere wasn’t reached until about 1950.
In May 1861 global coverage was a mere 12% – that’s less than one-eighth. In much of the 1860s and 1870s most of the supposedly global coverage was from Europe and its trade sea routes and ports, covering only about 13% of the Earth’s surface. To calculate averages from this data and refer to them as “global averages” is stretching credulity.
Another important finding of this audit is that many temperatures have been incorrectly adjusted.…
The overall conclusion … is that the data is not fit for global studies. Data prior to 1950 suffers from poor coverage and very likely multiple incorrect adjustments of station data. Data since that year has better coverage but still has the problem of data adjustments and a host of other issues mentioned in the audit.
Calculating the correct temperatures would require a huge amount of detailed data, time and effort, which is beyond the scope of this audit and perhaps even impossible. The primary conclusion of the audit is however that the dataset shows exaggerated warming and that global averages are far less certain than have been claimed.
One implication of the audit is that climate models have been tuned to match incorrect data, which would render incorrect their predictions of future temperatures and estimates of the human influence of temperatures.
Another implication is that the proposal that the Paris Climate Agreement adopt 1850-1899 averages as ‘indicative’ of pre-industrial temperatures is fatally flawed. During that period global coverage is low – it averages 30% across that time – and many land-based temperatures are very likely to be excessively adjusted and therefore incorrect. …
Ultimately it is the opinion of this author that the HadCRUT4 data, and any reports or claims based on it, do not form a credible basis for government policy on climate ….
Strangely, Dr McLean’s book was not mentioned by the ABC or the mainstream media. But it will have a growing effect on policymakers, I think.
For the link for purchasing copies of the McLean book, go to: