A last-ditch effort to refute climate “skeptics”—people unconvinced that we need to spend trillions to reshape our economies to halt or slow “climate change”-- has failed.
Last week, the National Academy of Sciences (NAS) published a study by 13 prestigious atmospheric scientists that supposedly provides “clear evidence for a discernible human influence on the thermal structure of the atmosphere.”
The NAS researchers pointedly echo the famous declaration by the United Nation-sponsored Intergovernmental Panel on Climate Change, or IPCC, that the “balance of evidence suggests a discernible human influence on global climate.” With this new study, the authors claim to clinch the case. The IPCC, we’re supposed to believe, has been right all along.
With the IPCC now issuing the first segment of its latest mammoth study on the same topic, readers should take the NAS pronouncement with a large grain of salt—and the IPCC report too. This is an attempt to change the subject and ignore the elephant in the room: the crisis in “consensus” climate science arising from the growing mismatch between model-predicted warming and observed warming.
The urgent issue in climate science today is not whether man-made global warming is real but whether the climate models that scientists use to predict it are realistic enough to assess future climate change and inform public policy. And scientists themselves are pointing this out.
The real, observable evidence increasingly shows that the models, which are no more than computer simulations based on the data and assumptions that scientists currently think are relevant, are way out of line with the changes that scientists are able to measure. And the gap is widening.
Consider some recent science on these matters.
John Christy, a distinguished climate scientist and director of the Earth System Science Center at the University of Alabama in Huntsville (UAH) found that all 73 computer model runs performed by the IPCC as of June 1, 2013 overshoot the observed warming of the tropical atmosphere during the previous 34 years.
And despite the fact that global carbon dioxide emissions are increasing more rapidly than most models assumed (due largely to industrial growth in India and China), the temperatures recorded by the NASA-supported Remote Sensing Systems shows no warming in the earth’s middle atmosphere, or troposphere, over the past 16-plus years.
German climatologist Hans von Storch has found that IPCC climate models project warming trends as low as actual recorded observations only 2% of the time.
The monthly journal Nature Climate Change reports that over 20 years (1993-2012), the warming trend computed from 117 climate model simulations (0.3°C per decade) is more than twice the observed trend (0.14°C/decade). Over the most recent 15 years (1998-2012), the computer-simulated trend (0.21°C/decade) is more than four times the observed trend (0.05°C/decade)—a trend that is pretty close to a flat line.
These are huge inconsistencies, and they matter because less warming means smaller climate impacts, and less ostensible need for radical changes in the way we live to deal with them.
The NAS researchers briefly note the discrepancy between warming projections and observations but then ignore its implications.
Rather than confront the failure of increasingly overstretched climate models, the NAS study emphasizes the agreement between satellite observations and the model-projected combination of warming in the troposphere and cooling in the atmospheric layer above it, the lower stratosphere.
It’s the match between the computer-projected “fingerprint” and the observed “thermal structure” that supposedly demonstrates a “discernible human influence” on global climate.
But there’s less to this finding than meets the eye, because according to the study, the “human influence” cooling the lower stratosphere is predominantly the presence of man-made ozone depleting substances, not greenhouse gases.
In fact, a study cited by the NAS researchers, found that the “influence of greenhouse gases” on stratospheric temperatures “is not yet clearly identifiable.” Contrary to appearances, they have not really found the smoking gun of man-made global warming.
But even if the NAS study did finally find the model-projected greenhouse “fingerprint” in the atmospheric data, it would not refute those who have long argued that the models are alarmist and project too much warming.
After all, few prominent skeptics of the sky-is-falling school of global warming actually deny that man-made climate change is real.
What they doubt is that climate change is a “planetary emergency” brought on by rapidly rising projected temperatures, that reducing carbon dioxide emissions would detectably benefit public health and welfare, and that mankind has nothing to fear from carbon taxes, cap-and-trade, renewable energy mandates, and other forms of centralized energy planning.
Those radical forms of social engineering, it turns out, are the real short-term threat of climate change. And the science-policy community that is pushing them is substituting heated rhetoric for real data that doesn’t support their agenda.
Marlo Lewis, Ph.D. is a Senior Fellow at the Competitive Enterprise Institute.