Tamper, tamper! How They failed to hide the gulf between predicted and observed warming
By Christopher Monckton of Brenchley
The indefatigable Roy Spencer at the University of Alabama at Huntsville is the first to declare the global temperature anomaly for December 2017. As Fig. 1 shows, in the 39 years 1 month from December 1978 to December 2017, the planet has warmed by half a Celsius degree. But that is equivalent to 1.28 C°/century, or little more than one-third of the 3.3 C°/century predicted with “substantial confidence” by IPCC in 1990 and also by the fifth-generation general-circulation models of the Climate Model Intercomparison Project in 2013.
Fig. 1 The least-squares linear-regression trend on the entire UAH satellite shows monthly global mean surface temperature anomaly dataset shows warming at a rate equivalent to just 1.28 C°/century from December 1978 to December 2017.
Is the rate of global warming rising inexorably? The answer is No, as Fig. 2 shows:
Fig. 2 The least-squares trend on the UAH dataset shows warming at a rate equivalent to 0.85 C°/century from February 1997 to December 2017.
The warming rate in the 251 months of data that account for just over half the entire UAH dataset is not higher than the rate for the entire 469-month record. It is down by a third, from 1.28 0.85 C°/century. I chose the start date for Fig. 2 because it was also the start date for the longest period of the Great Pause, which – in the RSS satellite dataset – ran for a spectacular 18 years 9 months from February 1997 to October 2015, as Fig. 3 shows:
Fig. 3 The least-squares trend on the RSS satellite dataset shows no global warming for 18 years 9 months February 1997 to October 2015, the longest period of the Pause, though one-third of all anthropogenic forcings occurred during that period.
A little history. In preparation for a debate in the Senate at the end of 2015, Senator Ted Cruz approached the Heartland Institute to request its advice on the single graph that would most clearly encapsulate the climate-skeptical case. Fig. 3 was chosen, and Senator Cruz displayed it on the floor of the Senate, to the visible discomfiture of the Democrats. The late Bob Carter, shortly before his untimely death, wrote to me to say how pleased he was that we had added the line pointing out that one-third of Man’s entire influence on climate since 1750 had arisen during the Pause, but without causing any global warming at all.
In my report of the Pause in November 2017 at WattsUpWithThat, I predicted that the RSS dataset would swiftly be tampered with to try to eradicate the Pause. Just weeks later, Dr Carl Mears, the keeper of that dataset, who is prone to describe skeptics as “deniers”, announced that there would indeed be a revision, which, when it arrived, airbrushed the Pause away.
What is interesting is that the airbrushing – i.e., the alteration of data ex post facto to suit the Party Line – has continued. The dataset as it stood a few months back swept away the embarrassing zero trend over the 18 years 9 months of the Pause and replaced it with a trend equivalent to 0.77 C°/century (Fig. 4).
However, that tamperature change was not enough. The RSS dataset as it stands today shows a warming rate equivalent to 0.83 C°/century over exactly the same period (Fig. 5).
Fig. 4 The least-squares trend on the RSS dataset for the 18 years 9 months of the Pause, based on the data as they stood in mid-2017.
Fig. 5 The least-squares trend on the RSS dataset for the 18 years 9 months of the Pause, this time using the data as they stand today.
Contrast Figs. 4-5 with Fig. 6, the current UAH data for the 18 years 9 months of the Pause, which show the world warming at a statistically-insignificant 0.05 C°/century equivalent over the period of the Pause.
At the time of the Pause, the UAH data showed a higher rate of warming than RSS. Since then, the UAH data have been revised with the effect of reducing the formerly-evident small warming rate over the period of the Pause, while RSS has been – and continues to be – revised so as to increase the apparent warming rate over the same period.
On all of these data, it is evident that the rate of global warming is very considerably below what had originally been predicted. In a future article, I shall show just how large is the discrepancy between excitable prediction and unexciting observation, and just how false were the various artful claims in certain reviewed papers that IPCC’s original predictions were about right, and just how wrong those predictions – properly understood – truly were.
Finally, in due course I shall show exactly what error in the models has led to the extravagant over-predictions, and just how small the properly-predicted warming rate will be once that fatal error is corrected.
Fig. 6 The least-squares trend on the current UAH dataset agrees with the original RSS dataset in showing global warming at a rate statistically indistinguishable from zero in the 18 years 9 months February 1997 to October 2015.
via Watts Up With That? http://ift.tt/SkPwKf