The Pause is driving down the long-term warming trend

Guest essay by Christopher Monckton of Brenchley

The long and model-unpredicted Great Pause of 18 years 8 months in global mean lower-troposphere temperature as recorded in the RSS satellite monthly dataset is inexorably driving down the longer-run warming rate, when the IPCC’s predictions would have led us to expect an acceleration.

The graph shows the entire RSS lower-troposphere satellite dataset for the 440 months January 1979 to August 2015, with the bright blue trend on the entire series equivalent to just over 1.2 C°/century. Overlaid graph in green is the zero trend in the 224 months since January 1997 – more than half the entire 440-month record.

As one would expect, the point (2007-8) where the long-run trend-line intersects the Pause trend-line is the moment from which the Pause begins to reduce the long-run trend. As the table shows, the trend had been below 1 K/century till the Great El Niño of 1998 lifted it suddenly above 1.5 K/century. It remained there till 2008, since when it has been dropping gently. From January 1979 to August 2015, the trend was just 1.21 K/century.

In 1990, the IPCC had predicted near-straight-line warming of 1 K to 2025, equivalent to almost 2.8 K/century. Of this warming, more than 0.7 K should have happened by now, but only 0.26 K has actually occurred. The IPCC’s central estimate in 1990, though made on the basis of “substantial confidence” that the models on which it relied had captured all the essential features of the climate system, has proven – thus far, at any rate – to be a near-threefold exaggeration.

In the run-up to the Paris world government conference, the climate Communists are making determined efforts to pretend that the Pause does not exist, or that the rate of warming since 1990 is exactly as the IPCC had predicted. Both pretenses are false. The UAH and RSS satellite data both show the Pause, though the terrestrial tamperature datasets have all been altered in the past year with the effect of concealing it.

Furthermore, the warming rate is now embarrassingly far below prediction. It is worth demonstrating this fact with the IPCC’s own graphs:

The above graph is interesting, because in pale blue it shows the IPCC’s current generation of models – 42 of them – making predictions on the assumption that drastic reductions in CO2 emissions are made. Yet observed temperatures, shown in black, are already visibly at odds with – and falling below – even the least the prediction, and a long way below the central prediction.

As a result of the IPCC’s admission that 111 of its 114 models had over-predicted the warming rate in recent decades, it produced the above graph in its 2013 Fifth Assessment Report, showing a considerable reduction in its near-term predictions.

Whenever the IPCC produces graphs to a tiny scale, it is worth enlarging them to see what is being hidden. The above graph is a considerable enlargement of a tiny corner of an IPCC graph from the Fifth Assessment Report, illustrating clearly (at this scale) the extent to which observed temperatures have failed to keep pace with the models’ exaggerated predictions. CMIP3 was the ensemble of models for the 2007 Fourth Assessment Report: CMIP5 is the current ensemble. Both over-predict, but the latest models (in red) over-predict less drastically than the earlier models (in blue), when compared with observed temperatures (in black).

The above graph shows how drastically the IPCC was compelled to reduce its near-term warming projections between the spaghetti-graph shown and the sharply downward-revised prediction zone between the two green arrows. The red arrows show where the medium-term predictions were in 1990. The observed trend, in black, is trailing along at the very bottom of the prediction zone.

The before-and-after graphs above show the change in the IPCC’s predictions between its pre-final and final drafts of the Fifth Assessment Report.

A point worth making to those who continue to deny that there has been a Pause or that the discrepancy between prediction and reality continues to widen with each passing year is that all of the graphs in this posting, except the first, are IPCC graphs. If even the IPCC is now admitting that the models had exaggerated, it is time for the climate Communists to adjust the Party Line to bring it closer to the real world.

What, then, would be a logical and rational policy for nations to adopt at the forthcoming Paris summit to establish a global government (for the time being this will be called the “governing body”):

1. A secession clause is a freedom clause. Given the failure of prediction that is self-evident in the IPCC’s “consensus” documents, nations no longer willing to spend trillions on the basis of further alarming but probably exaggerated predictions should reserve the right to give a short period of notice and then leave the entire treaty process, and all obligations thereunder, without penalty. The Kyoto Protocol had a secession clause at Art. 27. The Treaty of Paris should have a secession clause also. However, the draft secession clause which – after much work by me and others – was in the Bonn draft earlier this year may well be dropped on grounds of shortening the current draft, so pressure should be brought to bear on your governments to ensure that the secession clause is not dropped.

2. A sunset clause is also advisable, to take account of a possible widening of the discrepancy between exaggerated prediction and unexciting, harmless observed reality. The entire treaty process would be brought to an end, all nations’ obligations thereunder would cease, and the UNFCCC and the IPCC would be abolished, if for any period of at least 20 years during the 21^st century the global warming rate, expressed as the least-squares linear-regression trend on any one of the five longest-standing monthly global surface or lower-troposphere temperature anomaly datasets, were to fall below 1 Celsius degree per century equivalent. In business, predictive failures are punished. In global government, let predictive failures be punished also, for the cost of the measures intended to address the non-problem of global warming is in any event disproportionate to the value any conceivable benefit.