The pause continues – Still no global warming for 17 years 9 months

According to the RSS satellite data, whose value for May 2014 has just been published, the global warming trend in the 17 years 9 years since September 1996 is zero (Fig. 1). The 213 months without global warming represent more than half the 425-month satellite data record since January 1979. No one now in high school has lived through global warming.

Figure 1. RSS monthly global mean lower-troposphere temperature anomalies (dark blue) and trend (thick bright blue line), September 1996 to May 2014, showing no trend for 17 years 9 months.

The hiatus period of 17 years 9 months is the farthest back one can go in the RSS satellite temperature record and still show a zero trend. But the length of the pause in global warming, significant though it now is, is of less importance than the ever-growing discrepancy between the temperature trends predicted by models and the less exciting real-world temperature change that has been observed.

The First Assessment Report 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 century^–1. 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.”

That “substantial confidence” was substantial over-confidence. A quarter of a century after 1990, the outturn to date – expressed as the least-squares linear-regression trend on the mean of the GISS, HadCRUT4 and NCDC monthly global mean surface temperature anomalies – is 0.34 Cº, equivalent to juar 1.4 Cº/century, or exactly half of the central estimate in IPCC (1990) and well below even the least estimate (Fig. 2).

Figure 2. Medium-term global temperature projections from IPCC (1990), January 1990 to April 2014 (orange region and red trend line), vs. observed anomalies (dark blue) and trend (bright blue) as the mean of the RSS and UAH monthly satellite lower-troposphere temperature anomalies.

Figure 3. Predicted temperature change since 2005 at a rate equivalent to 1.7 [1.0, 2.3] Cº/century (orange zone with thick red best-estimate trend line), compared with the observed anomalies (dark blue) and trend (bright blue).

Remarkably, even the IPCC’s latest and much reduced near-term global-warming projections are also excessive (Fig. 3).

In 1990, the IPCC’s central estimate of near-term warming was higher by two-thirds than it is today. Then it was 2.8 C/century equivalent. Now it is just 1.7 Cº – and, as Fig. 3 shows, even that is proving to be a substantial exaggeration.

On the RSS satellite data, there has been no statistically-significant global warming for more than 26 years. None of the models predicted that, in effect, there would be no global warming for a quarter of a century.

New attempts to explain away the severe and growing discrepancy between prediction and reality emerge almost every day. Far too few of the scientists behind the climate scare have yet been willing to admit the obvious explanation – that the models have been programmed to predict far more warming than is now likely.

The long Pause may well come to an end by this winter. An el Niño event has begun. The usual suspects have said it will be a record-breaker, but, as yet, there is too little information to say how much temporary warming it will cause. The temperature spikes caused by the el Niños of 1998, 2007, and 2010 are clearly visible in Figs. 1-3.

El Niños occur about every three or four years, though no one is entirely sure what triggers them. They cause a temporary spike in temperature, often followed by a sharp drop during the la Niña phase, as can be seen in 1999, 2008, and 2011-2012, where there was a “double-dip” la Niña.

The ratio of el Niños to la Niñas tends to fall during the 30-year negative or cooling phases of the Pacific Decadal Oscillation, the latest of which began in late 2001. So, though the Pause may pause for a few months at the turn of the year, it may well resume late in 2015.

Either way, it is ever clearer that global warming has not been happening at anything like the rate predicted by the climate models, and is not at all likely to occur even at the much-reduced rate now predicted. There could be as little as 1 Cº global warming this century, not the 3-4 Cº predicted by the IPCC.