by Bob Munck—-
Introduction
An argument we hear from both sides of the Global Warming (GW) debate goes something like this:
“There is a consensus among climate scientists that Global Warming exists and is caused by human activity; 97% of them agree.”
Those who deny the existence of GW, henceforth called “Deniers,” argue that such a statement is contrary to the very idea of the scientific method– that its results are not determined by majority vote.
The trouble is, the Deniers are right; science doesn’t work that way.
INSTEAD: It works in a way that is much, much better than that and–
when applied correctly, strongly affirms the hypothesis of human-caused global warming.
The 97% Study
There have been several studies of the corpus of papers published in the field of Climate Science on this topic. The most definitive is the 2013 paper in the journal Environmental Research Letters: Quantifying the consensus on anthropogenic global warming in the scientific literature by J. Cook et al.
That study examined 11,944 peer-reviewed papers published from 1991 to 2011 and found that:
… 66% of them, [7,930], were not concerned with GW,
… 33% [3,896] endorsed human-caused GW,
… 0.7% [78] rejected GW, and
… 0.3% [40] were ambiguous on it.
The oft-quoted 97% represents the ratio of endorsing papers to the total number addressing GW at all.
The authors present that 97% as their basic result.
The Better Way to Interpret Those Results
The actual and important result of that study is concealed in the results summarized above; in journalism terms, the authors buried the lede.
Those papers being surveyed are peer-reviewed technical papers published in professional journals; they are not editorials or “think pieces” or the random musing of a random scientist.
They are reports of the results of experiments, studies, or sets of observations that have been intensely inspected by the editorial staff of the publishing journals and by their peer reviewers to make certain that proper methodologies were used correctly to produce substantial, solid results.
Therefore those 3,896 papers are in fact 3,896 independent data points that agree with the hypothesis that global warming is happening; the 78 that reject it are data points disagreeing with it, and the remaining 40 are simply inconclusive.
That is an extremely solid affirmation of the hypothesis, more than sufficient to advance it to the status of a scientific theory.
This is also a very powerful statement: scientists “believe” that GW is happening because the great preponderance of data — some four thousand experiments and observational studies — support that belief.
So why did the authors of that study and the many scientists who have referred to it subsequently, all of whom should know better, use the word “consensus?”
It’s not impossible that they were making the same kind of mistake that members of the general public make when they see the word “theory” used in the scientific sense.
The lay meaning of “consensus” is “the majority of opinion” or “the general opinion,” but scientists don’t really deal in opinions.
They deal in suppositions (hypotheses) which, when supported by experiment or observation, become facts (theories).
With two of the key words of the discussion having different, even contradictory meanings to the two groups, is it any wonder that what we have here is a failure to communicate?
One Warning
The study apparently did not look at the 3,896 published papers to make sure that each one was, as I said above, a “report of the results of an experiment, study, or set of observations” supporting the theory of GW.
It’s possible that some tiny fraction of them were not; strange things sometimes get through the publication filters.
Possibly there are only 3,850 major data points that affirm the reality of human-caused global warming and 75 that contradict it. That’s still plenty.
Other Communication Problems
This is far from the only place that the scientific community is failing to communicate with the general public, and as a result giving the Deniers an opportunity to sow FUD (Fear, Uncertainty, and Doubt).
Another major example is the emphasis on air temperature as the metric of GW.
Global warming is essentially an increase in the total amount of heat energy stored in the Earth’s biosphere, but note that that biosphere includes the oceans as well as the atmosphere. It is rarely pointed out that 99.975% of the ability of the biosphere to store heat is in the oceans; four thousand times the heat capacity of the atmosphere.
Another way to put it is that the amount of thermal energy needed to raise the temperature of the oceans by 1/1000th of a degree would raise the temperature of the atmosphere by 4 degrees.
Another important fact in this area is that the thermal energy required to change a given mass of ice at 32°F to water at 32°F would raise the temperature of that mass of water by 144°F. Ice is melting in our polar regions at a rate in the hundreds of gigatons per year.
But perhaps that’s a topic for a later article.
Sound Bite
Some 4000+ experiments and observational studies good enough for professional publication have supported the fact that global warming is real and is caused by human activities. Only about eighty contradicted it.
The image, Public Domain
Bob Munck, Science trained and dedicated to explaining science in clear terms, has a “special affinity for the planet” [Mars]; “…a good friend of mine… was in charge of the optics on the Viking Mars Landers. I did some of the programming, so there are little pieces of my code sitting on the western slope of Chryse Planitia and at Utopia Planitia ON MARS.”
Spoken like a true sci-mind-full person, not to mention, his awesome endeavor. dr.e/ed.