Temperature analysis of 5 datasets shows the 'Great Pause' has endured for 13 years, 4 months

Time to sweep away the flawed, failed IPCC

By Christopher Monckton of Brenchley

HadCRUT4, always the tardiest of the five global-temperature datasets, has at last coughed up its monthly global mean surface temperature anomaly value for June. So here is a six-monthly update on changes in global temperature since 1950, the year when the IPCC says we might first have begun to affect the climate by increases in atmospheric CO2 concentration.

The three established terrestrial temperature dataset that publish global monthly anomalies are GISS, HadCRUT4, and NCDC. Graphs for each are below.

GISS, as usual, shows more global warming than the others – but not by much. At worst, then, global warming since 1950 has occurred at a rate equivalent to 1.25 [1.1, 1.4] Cº/century. The interval occurs because the combined measurement, coverage and bias uncertainties in the data are around 0.15 Cº.

The IPCC says it is near certain that we caused at least half of that warming – say, 0.65 [0.5, 0.8] Cº/century equivalent. If the IPCC and the much-tampered temperature records are right, and if there has been no significant downward pressure on global temperatures from natural forcings, we have been causing global warming at an unremarkable central rate of less than two-thirds of a Celsius degree per century.

Roughly speaking, the business-as-usual warming from all greenhouse gases in a century is the same as the warming to be expected from a doubling of CO2 concentration. Yet at present the entire interval of warming rates that might have been caused by us falls well below the least value in the predicted climate-sensitivity interval [1.5, 4.5] Cº.

The literature, however, does not provide much in the way of explicit backing for the IPCC’s near-certainty that we caused at least half of the global warming since 1950. Legates et al. (2013) showed that only 0.5% of 11,944 abstracts of papers on climate science and related matters published in the 21 years 1991-2011 had explicitly stated that global warming in recent decades was mostly manmade. Not 97%: just 0.5%.

As I found when I conducted a straw poll of 650 of the most skeptical skeptics on Earth, at the recent Heartland climate conference in Las Vegas, the consensus that Man may have caused some global warming since 1950 is in the region of 100%.

The publication of that result provoked an extraordinary outbreak of fury among climate extremists (as well as one or two grouchy skeptics). For years the true-believers had gotten away with pretending that “climate deniers” – their hate-speech term for anyone who applies the scientific method to the climate question – do not accept the basic science behind the greenhouse theory.

Now that that pretense is shown to have been false, they are gradually being compelled to accept that, as Alec Rawls has demonstrated in his distinguished series of articles on Keating’s fatuous $30,000 challenge to skeptics to “disprove” the official hypothesis, the true divide between skeptics and extremists is not, repeat not, on the question whether human emissions may cause some warming. It is on the question how much warming we may cause.

On that question, there is little consensus in the reviewed literature. But opinion among the tiny handful of authors who research the “how-much-warming” question is moving rapidly in the direction of little more than 1 Cº warming per CO2 doubling. From the point of view of the profiteers of doom (profiteers indeed: half a dozen enviro-freako lobby groups collected $150 million from the EU alone in eight years), the problem is that 1 Cº is no problem.

Just 1 Cº per doubling of CO2 concentration is simply not enough to require any “climate policy” or “climate action” at all. It requires neither mitigation nor even adaptation: for the eventual global temperature change in response to a quadrupling of CO2 concentration compared with today, after which fossil fuels would run out, would be little more than 2 Cº –well within the natural variability of the climate.

It is also worth comparing the three terrestrial and two satellite datasets from January 1979 to June 2014, the longest period for which all five provide data.

We can now rank the results since 1950 (left) and since 1979 (right):

Next, let us look at the Great Pause – the astonishing absence of any global warming at all for the past decade or two notwithstanding ever-more-rapid rises in atmospheric CO2 concentration. Taken as the mean of all five datasets, the Great Pause has endured for 160 months – i.e., 13 years 4 months:

The knockout blow to the models is delivered by a comparison between the rates of near-term global warming predicted by the IPCC and those that have been observed since.

The IPCC’s most recent Assessment Report, published in 2013, backcast its near-term predictions to 2005 so that they continued from the predictions of the previous Assessment Report published in 2007. One-sixth of a Celsius degree of warming should have happened since 2005, but, on the mean of all five datasets, none has actually occurred:

The divergence between fanciful prediction and measured reality is still more startling if one goes back to the predictions made by the IPCC in its First Assessment Report of 1990:

In 1990 the IPCC said with “substantial confidence” that its medium-term prediction (the orange region on the graph) was correct. It was wrong.

The rate of global warming since 1990, taken as the mean of the three terrestrial datasets, is half what the IPCC had then projected. The trend line of real-world temperature, in bright blue, falls well below the entire orange region representing the interval of near-term global warming predicted by the IPCC in 1990.

The IPCC’s “substantial confidence” had no justification. Events have confirmed that it was misplaced.

These errors in prediction are by no means trivial. The central purpose for which the IPCC was founded was to tell the world how much global warming we might expect. The predictions have repeatedly turned out to have been grievous exaggerations.

It is baffling that each successive IPCC report states with ever-greater “statistical” certainty that most of the global warming since 1950 was attributable to us when only 0.5% of papers in the reviewed literature explicitly attribute most of that warming to us, and when all IPCC temperature predictions have overshot reality by so wide – and so widening – a margin.

Not one of the models relied upon by the IPCC predicted as its central estimate in 1990 that by today there would be half the warming the IPCC had then predicted. Not one predicted as its central estimate a “pause” in global warming that has now endured for approaching a decade and a half on the average of all five major datasets.

There are now at least two dozen mutually incompatible explanations for these grave and growing discrepancies between prediction and observation. The most likely explanation, however, is very seldom put forward in the reviewed literature, and never in the mainstream news media, most of whom have been very careful never to tell their audiences how poorly the models have been performing.

By Occam’s razor, the simplest of all the explanations is the most likely to be true: namely, that the models are programmed to run far hotter than they should. They have been trained to yield a result profitable to those who operate them.

There is a simple cure for that. Pay the modelers only by results. If global temperature failed to fall anywhere within the projected 5%-95% uncertainty interval, the model in question would cease to be funded.

Likewise, the bastardization of science by the IPCC process, where open frauds are encouraged so long as they further the cause of more funding, and where governments anxious to raise more tax decide the final form of reports that advocate measures to do just that, must be brought at once to an end.

The IPCC never had a useful or legitimate scientific purpose. It was founded for purely political and not scientific reasons. It was flawed. It has failed. Time to sweep it away. It does not even deserve a place in the history books, except as a warning against the globalization of groupthink, and of government.