Not Significantly Different From Zero
There was a time when climate change alarmists stood confident in the approaching global warming apocalypse. Even a few years pause in the upward march of temperatures was shrugged off, the catastrophists smugly stating that it would take ten or more years without warming to throw a spanner into their disaster predictions. It has now been fifteen years without the promised meteoric rise in global temperatures predicted by the warmongering climatologists' computer models. Unsurprisingly, some of the anthropogenic global warming faithful have started to question current climate change dogma. In commentary in a journal dedicated to climate change, scientists have admitted that they've overestimated climate change for 20 years. What is more, they do not really know why their predictions have turned out so wrong.
Writing in Nature Climate Change, John C. Fyfe, Nathan P. Gillett and Francis W. Zwiers attempt to explain why global temperatures have stubbornly refused to rise in accordance with GCM model predictions. “Recent observed global warming is significantly less than that simulated by climate models,” they state. “This difference might be explained by some combination of errors in external forcing, model response and internal climate variability.”
In “Overestimated global warming over the past 20 years,” Fyfe et al. give climate science's dirty laundry a long needed airing. Here is how they state the climate prediction quandary:
Global mean surface temperature over the past 20 years (1993–2012) rose at a rate of 0.14 ± 0.06 °C per decade (95% confidence interval). This rate of warming is significantly slower than that simulated by the climate models participating in Phase 5 of the Coupled Model Intercomparison Project (CMIP5). To illustrate this, we considered trends in global mean surface temperature computed from 117 simulations of the climate by 37 CMIP5 models. These models generally simulate natural variability — including that associated with the El Niño–Southern Oscillation and explosive volcanic eruptions — as well as estimate the combined response of climate to changes in greenhouse gas concentrations, aerosol abundance (of sulphate, black carbon and organic carbon, for example), ozone concentrations (tropospheric and stratospheric), land use (for example, deforestation) and solar variability. By averaging simulated temperatures only at locations where corresponding observations exist, we find an average simulated rise in global mean surface temperature of 0.30 ± 0.02 °C per decade (using 95% confidence intervals on the model average). The observed rate of warming given above is less than half of this simulated rate, and only a few simulations provide warming trends within the range of observational uncertainty (Fig. 1a).
In other words, the models are not working; their predictions are off by 50% and almost all are not even within acceptable statistical error bounds. Evidently, when a climate scientist says his estimate is within 95% error bounds it really means that he is 95% sure that's his prediction, not that the climate is going to comply. The authors go on to note that the inconsistency between observed and simulated global warming is even more apparent for temperature trends over the past fifteen years (1998–2012). “For this period, the observed trend of 0.05 ± 0.08 °C per decade is more than four times smaller than the average simulated trend of 0.21 ± 0.03 °C per decade (Fig. 1b),” the paper reports. The referenced figure is shown below:
Trends in global mean surface temperature
In the figure above are two time spans: a, 1993–2012. b, 1998–2012. Histograms of observed trends (red hatching) are from 100 reconstructions of the HadCRUT4 dataset. Histograms of model trends (grey bars) are based on 117 simulations of the models, and black curves are smoothed versions of the model trends. The ranges of observed trends reflect observational uncertainty, whereas the ranges of model trends reflect forcing uncertainty, as well as differences in individual model responses to external forcings and uncertainty arising from internal climate variability.
The authors conclude, “It is worth noting that the observed trend over this period — not significantly different from zero — suggests a temporary ‘hiatus’ in global warming.” Never mind the use of 'temporary', all climate trends are temporary over time. The important thing here is that, not only is the lack of global warming admitted, this report quantifies how far off the computer models have been. What experienced computer modelers have known all along is certainly true—you live by simulation you can die by it as well.
Still, some warmists refuse to accept that reality is not behaving they way they predicted. Consider the extent of Arctic sea ice, the subject of much wailing and gnashing of teeth in recent years. Excitable scientists and news readers alike breathlessly predicted that the north pole would soon be completely ice-less during the summer, drowning polar bears and accelerating global warming. Yet something seems to have gone awry with the icepocalypse this year. According to the National Snow and Ice Data Center (NSIDC), Arctic sea ice averaged 2.35 million square miles in August 2013, as compared with the low point of 1.32 million square miles recorded on Sept. 16, 2012. Data published September 8th by NSIDC shows the dramatic rise this year, putting total ice cover within two standard deviations of the 30-year average.
About a million more square miles of ocean are covered in ice in 2013 than in 2012, a sizable 60% increase. Noting the year over year surge, one scientist even argued that “global cooling” was here. “We are already in a cooling trend, which I think will continue for the next 15 years at least. There is no doubt the warming of the 1980s and 1990s has stopped,” Anastasios Tsonis of the University of Wisconsin told London’s Mail on Sunday. Noting that, despite this year's growth, ice coverage was still well below the 30-year average. The green weenies at The Guardian argued the year over year growth in ice is “largely irrelevant.” When you buy into doomsday it is really hard to be dissuaded, even by reality. More rational minds are open to uncertainty.
Arctic ice cover in August 2012 (left) and 2013 (right).
“The absence of any significant change in the global annual average temperature over the past 16 years has become one of the most discussed topics in climate science,” wrote David Whitehouse of the Global Warming Policy Foundation in June. “It has certainly focused the debate about the relative importance of greenhouse gas forcing of the climate versus natural variability.”
In a letter posted in the Wall Street Journal, sixteen concerned scientists state that there is “No Need to Panic About Global Warming.” According to the authors, there's no compelling scientific argument for drastic action to 'decarbonize' the world's economy. This is how these known international scientists summarize the current state of affairs:
The lack of warming for more than a decade—indeed, the smaller-than-predicted warming over the 22 years since the U.N.'s Intergovernmental Panel on Climate Change (IPCC) began issuing projections—suggests that computer models have greatly exaggerated how much warming additional CO2 can cause. Faced with this embarrassment, those promoting alarm have shifted their drumbeat from warming to weather extremes, to enable anything unusual that happens in our chaotic climate to be ascribed to CO2.
After fifteen years of failure to perform, even the news media are beginning to suspect there is something wrong in climate prediction circles. In a scathing article in Forbes, Larry Bell writes: “One highly plausible answer to this mystery is that the climate models upon which IPCC’s failed projections are based exaggerate climate sensitivity to CO2, underestimate known natural forcings, and simply do not understand how to factor in and calibrate other influences such as ocean cycles and solar activity.”
The criticism is not coming from conservative magazines like Forbes alone. Even the notoriously pro-AGW New York Times finally recognized that the feverish climate fervor is overheated. They reported on June 6 that “The rise in the surface temperature of Earth has been markedly slower over the last 15 years than in the 20 years before that. And that lull in warming has occurred even as greenhouse gases have accumulated in the atmosphere at a record pace. highlights important gaps in our knowledge of the climate system is a bit of a mystery to climate scientists.”
It is no mystery, climate science is too immature to make realistic predictions. The first thing any scientist must realize it that what we think we know is insignificant compared with what remains to be discovered about nature. Forget that lesson and hubris will lead you astray, you might even start believing that your computer models are reality. It has been said many times—but evidently not at IPCC meetings—when science and nature disagree, nature wins. As Professor Bell puts it “so maybe the models are broke…not the climate after all!”
Be safe, enjoy the interglacial and stay skeptical.