When will 'The Pause' in global temperature return?

By Christopher Monckton of Brenchley

Another year, another failure of global warming to occur at even half the rate originally predicted by IPCC in 1990.

CO₂ emissions have increased at a rate somewhat above the high-end prediction made in IPCC’s First Assessment Report. In 2013 our sins of emission totaled 10.8 billion tonnes of carbon; in 2014 the official estimate, in the annual paper published by le Quéré et al., was 10.9 billion tonnes:

It is debatable whether the true rate of emissions growth is anything like as small as 0.1 billion tonnes of carbon per year, given that China and now India are bringing coal-fired power stations onstream at a record rate. But the official storyline is that emissions growth has all but stopped. Nevertheless, emissions remain a very long way above any of IPCC’s CO₂-stabilization scenarios.

On the business-as-usual Scenario A, IPCC (1990) predicted that global temperature would rise by 1.0 [0.7, 1.5] Cº to 2025, equivalent to 2.8 [1.9, 4.2] Cº per century. The executive summary asked, “How much confidence do we have in our predictions?” IPCC pointed out some uncertainties (clouds, oceans, etc.), but concluded:

“Nevertheless, … we have substantial confidence that models can predict at least the broad-scale features of climate change. … There are similarities between results from the coupled models using simple representations of the ocean and those using more sophisticated descriptions, and our understanding of such differences as do occur gives us some confidence in the results.”

Yet the rate of global warming since 1990 – the most important of the “broad-scale features of climate change” that the models were supposed to predict – is now below half what the IPCC had then predicted.

In 1990, IPCC said:

“Based on current models we predict:

“under the IPCC Business-as-Usual (Scenario A) emissions of greenhouse gases, a rate of increase of global mean temperature during the next century of about 0.3 Cº per decade (with an uncertainty range of 0.2 Cº to 0.5 Cº per decade), this is greater than that seen over the past 10,000 years. This will result in a likely increase in global mean temperature of about 1 Cº above the present value by 2025 and 3 Cº before the end of the next century. The rise will not be steady because of the influence of other factors” (p. xii).

Later, IPCC said:

“The numbers given below are based on high-resolution models, scaled to be consistent with our best estimate of global mean warming of 1.8 Cº by 2030 [compared with pre-industrial temperatures]. For values consistent with other estimates of global temperature rise, the numbers below should be reduced by 30% for the low estimate or increased by 50% for the high estimate” (p. xxiv).

In 1995 IPCC offered a prediction of the warming rates to be expected in response to various rates of increase in CO₂ concentration. The prediction based on the actual rate is highlighted:

The actual increase in CO₂ concentration in the two decades since 1995 has been 0.5% per year. So IPCC’s effective central prediction in 1995 was that there should have been 0.36 C° warming since then, equivalent to 1.8 C° century^–1.

In the 2001 Third Assessment Report, IPCC, at page 8 of the Summary for Policymakers, says: “For the periods 1990-2025 and 1990 to 2050, the projected increases are 0.4-1.1 C° and 0.8-2.6 C° respectively.” The mid-range estimate was for 0.7 C° warming in the 36 years 1990-2025, equivalent to 1.9 C° century^–1.

Table 1 summarizes these medium-term predicted global warming rates from the first three Assessment Reports:

It became rapidly evident that the business-as-usual global-warming predictions made by IPCC in the report that got the climate scare going were childishly wild exaggerations. The reasons for the exaggerations are many. Here are just a few. IPCC somewhat exaggerated the CO₂ concentration growth to be expected in response to a given rate of emissions growth; it extravagantly exaggerated the growth of methane concentration; it greatly exaggerated the CO₂ forcing; and it very greatly exaggerated the impact of strongly net-positive temperature feedbacks on climate sensitivity.

What, then, has happened to global temperatures in the real world since 1990? The answer, taken as the least-squares linear-regression trend on the mean of the RSS and UAH satellite datasets, is that the rate of global warming is less than half the mid-range rate originally predicted by IPCC in 1990, and well below even the low-end prediction:

The prediction zone in IPCC (1990) is shown in orange, with trend-lines in red. The real-world outturn is in dark blue and the trend on the real-world data is the bright blue line.

As far as I know, no mainstream news medium has reported this continuing and substantial discrepancy between the excitable predictions on the basis of which governments have squandered trillions for decades and the unexciting reality of a warming rate indistinguishable from natural internal variability.

It is worth looking at the entire satellite temperature record since 1979. First, RSS, whose inconvenient data showing far less warming than had been predicted are about to be revised sharply upward to bring the apparent rate of warming into accordance with the Party Line:

Next, UAH, whose dataset used to show a higher warming rate than all other datasets. However, adjustments were made last year when it was discovered that onboard instrumentation was heating the platinum-resistance thermometers, and UAH now shows a lower warming rate than all other datasets:

Taking the mean of the RSS and UAH datasets shows that the long-term rate of warming across the entire 39-year period since 1979 was just 1.3 C° century^–1 equivalent, or less than half of IPCC’s mid-range prediction in 1990:

It is essential to the high-climate-sensitivity theory profitably advanced by IPCC that the rate of global warming should not decline as the greenhouse gases in the atmosphere continue to accumulate, particularly where they continue to accumulate at a rate above IPCC’s original business-as-usual prediction.

A simple method of testing whether the rate of global warming has increased since 1979 is to determine the least-squares linear-regression trend on the data from a more recent starting date. I have chosen 1997, because that was just before the 1998 El Niño took hold. The mean of the two satellite datasets shows warming since 1997 at less than two-thirds of a degree per century, or just under half of the warming rate for the entire period since 1979.

Contrary to the high-sensitivity notion that continues to hold the international governing class in thrall (with the commendable exception of the incoming U.S administration), the rate of global warming is not accelerating. It is declining.

Some caution is necessary. At the turn of the millennium the Pacific Decadal Oscillation, an approximately 60-year cycle in ocean behavior which typically manifests itself as about 30 years’ warming followed by 30 years’ cooling, ended an unusually sharp positive (warming) phase and entered its negative (cooling) phase. It is possible, therefore, that some contribution from anthropogenic emissions is overlain upon this natural cycle, giving a false appearance of very rapid manmade warming from 1976-2000 and of little or no warming since.

What is now undeniable, however, is that the contribution of anthropogenic influences to global temperature is considerably less than had originally been predicted. How do I know this? Because IPCC itself has realized it cannot retain what little credibility it has left if it continues to make absurdly exaggerated medium-term predictions. It has all but halved them:

As every opinion poll shows that (as with Brexit and Trump) the people are no longer buying the Party Line, the only way They can now keep the dying climate scare alive is to leave Their long-term predictions unaltered, and to count on their poodles in the mainstream media to fail to report either the growing discrepancy between IPCC’s original medium-term predictions and observed reality or IPCC’s own near-halving of those predictions.

Mark Boslough, one of the few remaining climate extremists who has not yet slunk away into the long night, has provided an intriguing indication of the Party’s increasing desperation by offering $25,000 to anyone who will bet that GISS’ global temperature for 2017 will exceed that for 2016. There may be a la Niña this year, so that would be a bet worth taking – if, that is, one could trust GISS to maintain an honest global-temperature dataset.

It is not for me to cast nasturtiums at Dr Schmidt, so I shall say no more than that I’d happily take that bet if it were based on either the HadCRUT4 dataset now that the extremist Jones has gone or the mean of the RSS and UAH datasets even after Dr sMears has tampered with the RSS dataset to bring it into line with the tampering of the terrestrial datasets. But I shall take no decision based on any climate information from NASA until Mr Trump has reformed those racketeers.