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Defending the Indefensible: The National Climate Assessment Cherry Picks to Validate Models

By E. Calvin Beisner -- May 28, 2014

It’s become almost common knowledge that global climate computer models used to project future temperatures based on assumptions about greenhouse gas emissions miss the mark. So common that much of the American public even knows it.

But the National Climate Assessment released May 6, 2014, uses them anyway to predict future climate changes and their impact for the United States.

How does it defend that? By claiming that the models “do a good job at reproducing the broad features of the present climate and changes in climate, including the significant warming that has occurred over the last 50 years” (p. 809, FAQ-R).

How does it substantiate that claim? With this graphic:

Climate Model and Temperature Change


There are three big problems.

First, the claim was that the models “do a good job at reproducing the broad features of the present climate and changes in climate, including the significant warming that has occurred over the last 50 years.” But the graphic shows only 25 years, 1980–2005.

Second, as Dr. Roy Spencer, Principal Research Scientist in climatology at the University of Alabama, puts it, global climate models … are known to have essentially zero skill for regional (e.g. U.S.) predictions.” This means the moderately good fit between observed and modeled temperatures in the NCA’s graphic is likely to be mere coincidence. This is all the more likely since the globe as a whole was warming from 1980 through 1997 (excluding the anomalous 1998, extra warm because of an exceptionally strong El Niño).

Third, although not explicitly stated, the claim is that global climate models “do a good job.” But the graphic shows only North America. Global surface is 21 times North American. If the whole globe is warming, it’s likely that particular regions are warming; but the reverse isn’t true. Showing, then, that North America was warming (and only for half the period in question) doesn’t imply that the models’ predictions of warming for the whole world are reliable.

So how do the models do for the whole world? Not well, as this graphic by Dr. John Christy, Distinguished Professor of Atmospheric Science and Director of the Earth System Science Center at the University of Alabama in Huntsville, shows.

Global Midtropospheric


In short, to justify its claim that the models “do a good job” for the world over a 50-year period, the National Climate Assessment depicts data for less than a twentieth of the world over a half the time. In other words, it cherry picks both chronologically and geographically.

As if that weren’t bad enough, it then uses the global climate models, which have “essentially zero skill for regional (e.g. U.S.) predictions,” to predict climate not just for the United States as a whole (for which they have “essentially zero skill”) but for nine sub-regions (for which therefore they have even less skill). Result: Its predictions are not credible.


E. Calvin Beisner, Ph.D., is Founder and National Spokesman of The Cornwall Alliance for the Stewardship of Creation, of which Dr. Roy W. Spencer is a Senior Fellow.


  1. Jim Ramsay  

    Our local paper (Mobile Press Register) which is a part of AL.com is in the tank for the Climate Change Alarmists. An editorial, May 16, 2014 entitled “Drowning in Denial” by Kyle Whitmire used nothing more than a number of logical fallacies (in particular argumentum ad populum) to deride the “climate change deniers” in Alabama as being ignorant and resistant to the un-debatable fact of the impending catastrophe caused by mankind’s contribution to global warming. I responded (yet to be published) by calling the author out on his arrogance and fallacious argument (he produced no facts), but I rarely see this done by climate change “experts”. Is there any reason why I can’t have some help in debating people like this?


  2. Gary H  

    Speaking of cherry picking. Up front in the section “Our Changing Climate,” this, on hurricanes, is presented:

    8. The intensity, frequency, and duration of North Atlantic hurricanes, as well as the frequency of the strongest (Category 4 and 5) hurricanes, have all increased since the early 1980s. . .”

    Since the early 1980’s? Well sure. That’s when our hurricane scientists/meteorologists were predicting that the Atlantic cycle of increasing frequency/intensity of storms was expected to pick up a bit.

    And, how’s that trend coming along for the past 8-9 years?

    Also, historically, we’ve categorized major hurricanes as Cat 3,4, and 5. When reality doesn’t fit – well, let’s narrow it down to a meaningless period of time and only look at cat 4 & 5 storms.


  3. kristy  

    Here’s a couple other cherry picks. I was reading the National Climate Assessment and noticed they used outdated information from the 2007 AR4 IPCC report on equilibrium sensitivity. This is what they used:

    From the National Climate Assessment Report:

    The equilibrium sensitivity has long been estimated to be in
    the range of 2.7 F to 8.1 F. The 2007 IPCC Fourth Assessment Report refined this range based on more recent evidence to conclude that the value is likely to be in the range of 3.6 F (2 C) to 8.1 F (4.5 C) with a most probable value of about 5.4 F (3C) based on multiple observational and modeling constraints and that it is very unlikely to be less than 2.7.

    They had the AR5 at the time which has updated the ES, but chose not to use that.

    Another cherry pick was on hurricanes. It stated hurricanes have increased, but only used data starting at 1980.


  4. Mark Vancil  

    Calvin, global climate clearly has been warming, not cooling.

    Climate model accuracy is high. The graph you showed us is limited in scope. Why not use a comprehensive graph as shown below? The pattern of warming and projected warming is crystal clear.



  5. rbradley  


    The models did not predict the last 15+ years of basically flat temperatures, what Richard Kerr in Science some years ago called ‘the pause’.

    Here is what he said in 2009: “Pauses as long as 15 years are rare in the simulations, and ‘we expect that [real-world] warming will resume in the next few years,’ the Hadley Centre group writes…. Researchers … agree that no sort of natural variability can hold off greenhouse warming much longer.”

    If you can provide any references from the 1990s or before, say 2005, on ‘the pause’ that predicted it or predicted a continued pause, I know our readers will be interested.

    See here: http://www.masterresource.org/2014/01/kerr-science-2009-pause-jolt/


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