Welcome to Quadrant Online | Login/ Register Cart (0) $0 View Cart
August 23rd 2013 print

John McLean

The ’95% certainty’ is that the IPCC can’t be trusted

The upcoming IPCC report is the end result of a convoluted process that mangles science and then smothers whatever of value remains with nakedly politically re-writes and tinkering

A leaked draft from the IPCC report, due for release in September, demonstrates yet again that the organisation makes a travesty of science and should be disbanded. The report claims that scientists are "95% sure"  humans are to blame for climate change, and it blames the past 15 years’ absence of warming on three factors: volcanic ash, less heat from the sun, and more heat being absorbed by oceans.

The statement is such a conglomeration of fraud, denial and lack of logic that the quest for a grain of truth is daunting exercise made more so by the way in which the reports are written, edited, re-written and then, at the very end, apt to be recast all over again in the interests of politics and political expedience.

Consider that claim of "95% certainty", which is no more than an opinion expressed by a few IPCC authors and approved by a few others.  It has no basis in mathematics or statistics and might just as well have been have been plucked from thin air, which may indeed have been the case.  It is, however, in general accordance with IPCC guidance documents describing how opinions and uncertainties are to be expressed as percentages.  The IPCC maintains it is acceptable to use "expert opinion" in determining these uncertainties, but the track record of IPCC projections and the tissue-thin support for its principal argument that humans are overheating the planet cast doubt on the presence of any genuine experts within the organization.

Consumer authorities would come down hard on any company selling a product billed as "likely safe" (i.e. between 66% and 75%), but apparently it’s OK to spend billions of dollars on such vague statements about scientific matters relating to climate.

The IPCC’s claim that the recent absence of warming is at least partly due to volcanic ash is ludicrous.  Fifty percent of the Earth’s surface falls between latitudes 30N and 30S, but there have been very few large eruptions in that region over the last 15 years.  We have to go back to the Philippines’ Mount Pinatubo in 1991 and Mexico’s El Chichon in 1982 to find volcanoes that caused even a few tenths of a degree of cooling, and even in those cases the effects lasted just a few years.  As the IPCC’s previous reports projected continual warming, the last decade and a half would have needed to see not merely sustained vulcanism but eruptions increasing in strength if the shortfall in predicted temperatures is to be explained. This hasn’t occurred, leading to the conclusion that the IPCC’s claim is fabrication at its worst.

Nor is consistency one of the IPCC’s strengths. The 2007 report claimed the small increases in heat from the sun were insufficient to cause warming.  Now it has back-flipped and suggests a decrease in heat from the sun can cause cooling! The IPCC can’t have it both ways. Either the sun’s output influences average global temperature or it doesn’t.

More heat being absorbed by the oceans is a straw to which the IPCC, and more than one climate scientist, has been clinging for some time.  The deep ocean is said to have warmed by a very small increment, but the data on which this conclusion is based has become available only in the last decade and the temperature variation is within the range of instrument error. On top of that, questions have been asked about why certain data was excluded from the analysis.

One might also ask how the heat managed to avoid land areas and disappear into the deep ocean without warming the ocean surface or being detected in transit.  Can anyone explain why this deep ocean warming should happen now when there has been no suggestion of it having happened in the 1980s and 1990s, when average global temperatures were rising?  I suspect the answer is no.

With the report due in less than a month, this is a good time to recall the high-level endorsement of previous IPCC efforts.  Prime Minister Kevin Rudd, for example, has attempted to boost the IPCC’s credibility by asserting that around 4000 scientists endorse the reports’ statements. The fact of the matter is that any one section is likely to be the work of no more than 10 authors. The IPCC generates its reports via a process that generally sees one or two contributing authors write the original section texts, which are then massaged by a similarly small number of Lead Authors. Alternatively, those Lead Authors might use the contributions as guides and references while doing the writing themselves.  Sitting above the Lead Authors are the Coordinating Lead Authors, typically two or three, who oversee the entire chapter for which they are responsible.

What all this means is that only a handful of people write section texts, and/or accept what is passed up to them.  This text, of course, includes levels of certainty/uncertainty expressed as percentages in accordance with IPCC protocols, as mentioned above.

At this point it is the turn of politics to shape what will be the final document.  Governments’ representatives haggle over words and phrases in the Summary for Policymakers.  Any semblance of science that has survived the earlier stages of the process now disappears, a casualty of the political operatives who decide what the SPM will say.

Mendacity, distortion, logical inconsistency and cherry-picking are the hallmarks of the IPCC, the key components of whose supposedly scientific reports are decided by political operatives carrying out their governments’ wishes.

From start to finish the IPCC method is a recipe for disaster. The latest inane and dishonest utterances about that "95% certainty" come as further confirmation that the IPCC and its dubious methods should have been scuttled years ago.

John McLean has been a critic of the IPCC since its 2007 report, his work being widely cited in a number of books as well as in the US Senate. His review of  the second draft of the  forthcoming IPCC report resulted in more than 500 comments, most noting the absence of supporting evidence