A Climate of Belief

[note, footnote links will only work if you go to original article ~ ctm]

Reposted from skeptic.com

The following is Patrick Frank’s controversial article challenging data and climate models on global warming. Patrick Frank is a Ph.D. chemist with more than 50 peer-reviewed articles. He has previously published in Skeptic on the noble savage myth, as well as in Theology and Science on the designer universe myth and in Free Inquiry, with Thomas H. Ray, on the science is philosophy myth.A Climate of Belief

The claim that anthropogenic CO₂ is responsible for the current warming of Earth climate is scientifically insupportable because climate models are unreliable

by Patrick Frank

“He who refuses to do arithmetic is doomed to talk nonsense.”

— John McCarthy¹

“The latest scientific data confirm that the earth’s climate is rapidly changing. … The cause? A thickening layer of carbon dioxide pollution, mostly from power plants and automobiles, that traps heat in the atmosphere. … [A]verage U.S. temperatures could rise another 3 to 9 degrees by the end of the century … Sea levels will rise, [and h]eat waves will be more frequent and more intense. Droughts and wildfires will occur more often. Disease-carrying mosquitoes will expand their range. And species will be pushed to extinction.”

So says the National Resources Defense Council,² with agreement by the Sierra Club,³ Greenpeace,⁴ National Geographic,⁵ the US National Academy of Sciences,⁶ and the US Congressional House leadership.⁷ Concurrent views are widespread,⁸ as a visit to the internet or any good bookstore will verify.

Since at least the 1995 Second Assessment Report, the UN Intergovernmental Panel on Climate Change (IPCC) has been making increasingly assured statements that human-produced carbon dioxide (CO₂) is influencing the climate, and is the chief cause of the global warming trend in evidence since about 1900. The current level of atmospheric CO₂ is about 390 parts per million by volume (ppmv), or 0.039% by volume of the atmosphere, and in 1900 was about 295 ppmv. If the 20th century trend continues unabated, by about 2050 atmospheric CO₂ will have doubled to about 600 ppmv. This is the basis for the usual “doubled CO₂” scenario.

Doubled CO₂ is a bench-mark for climate scientists in evaluating greenhouse warming. Earth receives about 342 watts per square meter (W/m²) of incoming solar energy, and all of this energy eventually finds its way back out into space. However, CO₂ and other greenhouse gasses, most notably water vapor, absorb some of the outgoing energy and warm the atmosphere. This is the greenhouse effect. Without it Earth’s average surface temperature would be a frigid -19°C (-2.2 F). With it, the surface warms to about +14°C (57 F) overall, making Earth habitable.⁹

With more CO₂, more outgoing radiant energy is absorbed, changing the thermal dynamics of the atmosphere. All the extra greenhouse gasses that have entered the atmosphere since 1900, including CO₂, equate to an extra 2.7 W/m² of energy absorption by the atmosphere.¹⁰ This is the worrisome greenhouse effect.

On February 2, 2007, the IPCC released the Working Group I (WGI) “Summary for Policymakers” (SPM) report on Earth climate,¹¹ which is an executive summary of the science supporting the predictions quoted above. The full “Fourth Assessment Report” (4AR) came out in sections during 2007.

Figure 1 shows a black-and-white version of the “Special Report on Emission Scenarios” (SRES) Figure SPM-5 of the IPCC WGI, which projects the future of global average temperatures. These projections¹² were made using General Circulation Models (GCMs). GCMs are computer programs that calculate the physical manifestations of climate, including how Earth systems such as the world oceans, the polar ice caps, and the atmosphere dynamically respond to various forcings. Forcings and feedbacks are the elements that inject or mediate energy flux in the climate system, and include sunlight, ocean currents, storms and clouds, the albedo (the reflectivity of Earth), and the greenhouse gasses water vapor, CO₂, methane, nitrous oxide, and chlorofluorocarbons.

In Figure 1, the B1 scenario assumes that atmospheric CO₂ will level off at 600 ppmv, A1B assumes growth to 850 ppmv, and A2 reaches its maximum at a pessimistic 1250 ppmv. The “Year 2000” scenario optimistically reflects CO₂stabilized at 390 ppmv.

The original caption to Figure SPM-5 said, in part: “Solid lines are multi-model global averages of surface warming (relative to 1980–99) for the scenarios A2, A1B and B1, shown as continuations of the 20th century simulations. Shading denotes the plus/minus one standard deviation range of individual model annual averages.”

Well and good. We look at the projections and see that the error bars don’t make much difference. No matter what, global temperatures are predicted to increase significantly during the 21st century. A little cloud of despair impinges with the realization that there is no way at all that atmospheric CO₂ will be stabilized at its present level. The Year 2000 scenario is there only for contrast. The science is in order here, and we can look forward to a 21st century of human-made climate warming, with all its attendant dangers. Are you feeling guilty yet?

But maybe things aren’t so cut-and-dried. In 2001, a paper published in the journal Climate Research¹³ candidly discussed uncertainties in the physics that informs the GCMs. This paper was very controversial and incited a debate.¹⁴But for all that was controverted, the basic physical uncertainties were not disputed. It turns out that uncertainties in the energetic responses of Earth climate systems are more than 10 times larger than the entire energetic effect of increased CO₂.¹⁵ If the uncertainty is larger than the effect, the effect itself becomes moot. If the effect itself is debatable, then what is the IPCC talking about? And from where comes the certainty of a large CO₂ impact on climate?

With that in mind, look again at the IPCC Legend for Figure SPM-5. It reports that the “[s]hading denotes the plus/minus one standard deviation range of individual model annual averages.” The lines on the Figure represent averages of the annual GCM projected temperatures. The Legend is saying that 68% of the time (one standard deviation), the projections of the models will fall within the shaded regions. It’s not saying that the shaded regions display the physical reliability of the projections. The shaded regions aren’t telling us anything about the physical uncertainty of temperature predictions. They’re telling us about the numerical instability of climate models. The message of the Legend is that climate models won’t produce exactly the same trend twice. They’re just guaranteed to get within the shadings 68% of the time.¹⁶

This point is so important that it bears a simple illustration to make it very clear. Suppose I had a computer model of common arithmetic that said 2+2=5±0.1. Every time I ran the model, there was a 68% chance that the result of 2+2 would be within 0.1 unit of 5. My shaded region would be ±0.1 unit wide. If 40 research groups had 40 slightly different computer models of arithmetic that gave similar results, we could all congratulate ourselves on a consensus. Suppose that after much work, we improved our models so that they gave 2+2=5±0.01. We could then claim our models were 10 times better than before. But they’d all be exactly as wrong as before, too, because exact arithmetic proves that 2+2=4. This example illustrates the critical difference between precision and accuracy.

In Figure 1, the shaded regions are about the calculational imprecision of the computer models. They are not about the physical accuracy of the projections. They don’t tell us anything about physical accuracy. But physical accuracy — reliability — is always what we’re looking for in a prediction about future real-world events. It’s on this point — the physical accuracy of General Circulation Models — that the rest of this article will dwell.

Read the rest here.

h/t dbstealey