Meet The Denominator

As most here have followed the climate issue for some time I'm sure we have each been faced with climate skeptics throwing out big numbers related to different aspects of climate science.

There is the ever present "31,000 Scientists Who Challenge Global Warming," the infamous Oregon Petition.

And then many of us have run into the ever ravenous PopTech (Andrew) and his, now, 850 Peer-Reviewed Papers Supporting Skepticism of "Man-Made" Global Warming (AGW) Alarm

These folks have yet to meet….   The Denominator!

Fig 1  -  Okay, this is really the Terminator but bear with me, the effect is about the same.

In this exercise we are going to give both the Oregon Petition and PopTech's 850 papers the benefit of the doubt.  We know there are many many reasons to challenge the assumptions of their claims but there is one thing they can not defend.  They are only presenting one side of the equation.

First, let's look at the Oregon Petition.  They define "scientist" as anyone with a BS degree or better. They state, "This includes primarily those with BS, MS, or PhD degrees in science, engineering, or related disciplines."  Thus, 31,000 is their numerator.

According to the US Census for 2000, 28 million people had bachelors degrees and 16 million had graduate or professional degrees.  We'll safely assume that half of the bachelor degrees are BA's and not BS degrees.  In 2000 that represented about 10% of the population.  If the proportions hold today it leaves us with a total of 31 million people of the current US population of 312 million (Note: the Oregon Petition is limited to the US).

Numerator, meet The Denominator!  31,000 over 31,200,000 comes to 0.00099.  Or roughly 0.1% of persons holding a BS or better have signed the petition challenging anthropogenic global warming, assuming that every single signature on the list is legitimate.  This is what The Denominator does.  He crushes big numbers into itty-bitty numbers.

Now let's look at PopTech's 850 papers.  Even mainstream skeptics like Roger Pielke Jr. as well as others have taken exception to PopTech's list but again, we're going to give him the benefit of the doubt and allow him the concept that 850 peer reviewed papers actually do challenge AGW alarm.  (I know it's a stretch but we're going to cut him a break, this time.)

Here I just went to Google Scholar.  I limited the search to the term "climate change" and only searched articles in the subject areas of 1) Biology, Life Science and Environmental Science, and 2) Physics, Astronomy and Planetary Science.  That returned 954,000 articles.  I did a pretty thorough perusal of 200 articles of the 100 pages of results and it looks like they are all actual papers and not just references to any blogs or websites.  A number are listed as "[citation]" so we might pull out about 10% for good measure.  But everything else looks to be published works in a very wide variety of scientific journals.  I intentionally left out the 177,000 papers that result when I do the same search on "global warming" since I don't know how many of those will be duplicate hits.

Numerator, meet The Denominator!  What we are left with is about 850,000 peer reviewed papers on climate change for the 850 peer reviewed papers that PopTech presents.  That leaves our friend with 0.1% of peer reviewed papers that challenge AGW alarm, as defined by him.

I'm sure some folks will find ways to quibble about the numbers but I don't think even the very best debater can appreciably alter the resulting percentages.  And if they try…

"I'll be back."

Update (Feb 18):  In the comments Poptech has brought up several valid points about the search results I came up with.  In an effort to better quantify the denominator I did some additional research. I did year by year searches going back 40 years on "climate change" and "global warming", excluded citations, and checked for various other erroneous results.

The outcome was, without even addressing the accuracy of the numerator, that the percentage does not change dramatically.  My first cursory search returned 0.1%.  The more detailed work resulted in 0.45%.  It's a big improvement for Poptech, by almost a factor of 5, but still the denominator is so large that it dwarfs the numerator. If a qualified outside group were to audit Poptech's list I believe the numerator would also shrink significantly.

There is plenty of room for skepticism in all areas of science. Good science relies on healthy skepticism.  One highly biased individual creating a subjective list does not rise to the level of good scientific skepticism.

Posted by Rob Honeycutt on Sunday, 13 February, 2011