Global warming, The Wall Street Journal, and John Gordon

John Steele Gordon published a commentary in The Wall Street Journal on July 30 that, on its face, sounds reasonable.  Gordon makes the case that we should be cautious about calling climate science settled as science is always changing.  No real quibbles there, as science has shown that nothing is ever truly "settled" science.  Unfortunately, that's as close to reality as Gordon comes.  The rest of the commentary simply shows off Gordon's simplistic view of history, science, and, especially, the current state of climate science.

Quote: "The Greek philosopher Aristarchus suggested a heliocentric model of the solar system as early as the third century B.C. But it was Ptolemy’s geocentric model from the second century A.D. that predominated. It took until the mid-19th century to solve the puzzle definitively."

 Gordon's first illustration nicely displays his simplistic view of science and history.  He is correct that Aristarchus proposed a heliocentric model in the third century B.C.  Other than that, there is much that he leaves out as it ruins his narrative.  For example, he doesn't consider why Ptolemy's geocentric model (proposed in AD 150, by the way) won out: The Catholic Church adopted Ptolemy's geocentric model because their leaders interpreted certain Bible verses to mean that the Earth had to be stationary.  This lead to religious persecution of anyone who didn't toe the Church's line.  Even after Copernicus published his heliocentric model, the Church hounded its proponents, burning Italian scientist Giordano Bruno at the stake and imprisoning Galileo Galilie for life.  Gordon also ignores how no serious scientist supported a geocentric model after Newton published his Philosophiae Naturalis Principia Mathematica in AD 1687 to the point where even the Catholic Church grudgingly accepted it in AD 1757, a century before Gordon claims the puzzle was definitively solved.  It's much simpler to ignore all that messy history of religious opposition to a scientific idea and pretend that it took 2,100 years because of scientific uncertainty as Gordon did.  The reality is that Copernicus published his model in AD 1543.  It only took 144 years after that before the scientific debate over the geocentric and heliocentric models was over.  That isn't too bad considering the opposition.

Quote: "Assuming that “the science is settled” can only impede science. For example, there has never been so settled a branch of science as Newtonian physics. But in the 1840s, as telescopes improved, it was noticed that Mercury’s orbit stubbornly failed to behave as Newtonian equations said that it should....When Mercury’s orbit was calculated using Einstein’s equations rather than Newton’s, the planet turned out to be exactly where Einstein said it would be, one of the early proofs of general relativity."

Gordon implies that someone would have come up with the general theory of relativity far sooner than Einstein if only scientists had discarded Newton's ideas at the first sign of difficulty.  That simply ignores reality.  Scientists never discard well-tested ideas at the first sign of difficulty—they seek out the simplest explanation for the difficulty and then figure out if the observations are wrong (see, for example, those CERN "faster-than-light" neutrino observations that turned out to be the result of a loose cable), existing theory needs tweaking, or if a new theory is necessary.  In this case, Newton's principles had just been used to predict the existence of a new planet (Neptune).  So what would be simpler when a similar situation arose with Mercury's orbit?  To discard a theory that had just made a successful prediction of a new planet and come up with general relativity?  Or to assume that astronomers had missed something and use that up-to-now successful theory to predict the existence of a new, as-yet-undiscovered planet?  Gordon basically claims that they should have discarded Newtonian physics immediately and created general relativity, thereby showing that he has a very simplistic, unrealistic understanding of how science works.

Quote: "Climate science today is a veritable cornucopia of unanswered questions. Why did the warming trend between 1978 and 1998 cease, although computer climate models predict steady warming?"

 First off, there is zero evidence that the warming trend ceased after 1998, as I detailed in an earlier post.  All I would add to that earlier post is this: Calculate the trend from 1978 to 1998, then extend it to 2014.  Here is the result of that exercise using GISS data:

1978-1998 trend extended to 2014, along with 1 standard deviation (dotted lines) and 2 standard deviations (dotted and dashed lines) around that trend.

I added lines denoting 1 and 2 standard deviations around the trend.  Temperatures since 1998 track the trend very well, staying within one standard deviation of that trend since 1998.  As I showed in that earlier post, the entire "pause" is a statistical artifact caused by using 1998 as a start point. See that outlier point on the graph above that is nearly 2 standard deviations above the trend?  That's 1998.  Starting there artificially flattens the trend, wrongly making it appear that the trend has "stopped" when in reality the trend remains unchanged.

Second, the discrepancy between climate models and temperature observations has been largely explained as a combination of random model inputs (especially El Niño/Southern Oscillation values), incomplete data, and a cool bias in observed global temperature records (Foster and Rahmstorf 2011, Rahmstorf et al. 2012, Kosaka and Xie 2013, Rohde et al. 2013, Cowtan and Way 2014, Risbey et al. 2014, Cowtan et al. 2015).  Observed global temperatures are a mix of air temperature over land and sea surface (water) temperature over the oceans whereas climate models predict only air temperatures.  That difference accounts for 40% of the discrepancy between modeled and actual temperatures.  The remaining discrepancy is due to model inputs (ENSO, aerosols, volcanic eruptions, etc) that are nearly impossible to predict and incomplete data.

Quote: "How sensitive is the climate to increased carbon-dioxide levels?"

Finally, a genuine question that remains a point of actual debate in the scientific community.  That doesn't mean that we don't have a good idea of what that value is, however.  We have good estimates from multiple lines of evidence if one is willing to read the scientific literature.

Climate sensitivity estimated from various lines of evidence.  From Knutti and Hegerl 2008

However, there are two crucial points that get overlooked, at least in the public debate.  First, if climate sensitivity is low (~1.5ºC per doubling of carbon dioxide), then so too is the calculated temperature difference between the last ice age and today.  If climate sensitivity is high (~6ºC per doubling), then so too is the calculated difference between today and the last ice age.  In other words, if climate sensitivity is low, the actual climate of the planet becomes more sensitive to changes in global temperature.  After all, which is more sensitive? A 3.5ºC drop in global average temperature causing a 2 km-thick ice sheet to cover most of North America or a 2ºC drop causing the same thing?  If the low climate sensitivity crowd is right, we can expect even greater changes than we've already observed, even if actual temperatures do not rise much more than the roughly 0.8ºC we've already measured.  That, to me, is not good news.

The second point?  Climate sensitivity is not unique to just carbon dioxide.  Climate is not magically more sensitive to one factor (solar, volcanic, etc) than another.  If climate sensitivity to carbon dioxide is low, then climate sensitivity to all factors is similarly low.

Quote: "What feedback mechanisms are there that would increase or decrease that sensitivity?"

All Gordon had to do to answer this one was peruse an IPCC report.  Section 8.6 of the 2007 report presents a good summary of the various known climate sensitivity feedback mechanisms.  Chapter 8 of the 2013 report presents the various influences on radiative forcing.  Then there are various sources such as Skeptical Science which provide a good summary of the scientific literature on the subject.  Or, if one prefers, there is the scientific literature itself.

The main question isn't what feedback mechanisms influence climate sensitivity.  The main question is when various feedback mechanisms kick in.  At what point will the tundra release enough methane and carbon dioxide to drive global warming and how rapidly will that release occur?  At what point will methane clathrates on the sea floor destabilize?  At what point will the ice sheets on Greenland and Antarctica destabilize and how quickly will sea levels rise because of it (the subject of the recent Hansen et al. (2015) paper)?

Gordon simply asked the wrong question here.  We already know the feedback mechanisms.  What is still up for question is when and how fast those mechanisms will occur.

Quote: "Why did episodes of high carbon-dioxide levels in the atmosphere earlier in Earth’s history have temperature levels both above and below the average?"

Here, Gordon really should have either done some reading or asked someone who had done some reading.  This question was answered nearly a decade ago.  Dr. Dana Royer published a paper in 2006 that explicitly examined this very question.  He found that solar output answered much of the conundrum.  The sun was weaker in the past, putting out far less energy than it does now.  The higher carbon dioxide levels in the past balanced out the cooler sun.

Figure 2 from Royer 2006 combining solar output and carbon dioxide levels.  Vertical gray bars indicate major ice ages.  The zero line on the y-axis represents the pre-industrial raidiative forcing value.

Comparing Royer's Figure 2 with his Figure 1 shows that major ice ages occurred whenever carbon dioxide levels dropped.

Figure 1 from Royer (2006) showing estimate carbon dioxide levels over time.

Quote: "With so many questions still unanswered, why are many climate scientists, politicians—and the left generally—so anxious to lock down the science of climatology and engage in protracted name-calling?  Well, one powerful explanation for the politicians is obvious: self-interest."

 Ironic, isn't it?  Three out of Gordon's four questions were answered years ago and the fourth, while not definitively answered, isn't exactly unanswered either.  Yet he claims that all are unanswered questions and castigates his political opponents on the basis of his own ignorance of climate science.  Here's something Gordon might want to learn: Just because he himself is ignorant in certain areas doesn't mean that everyone is.  All he's done here is the logical fallacy of projection.

Quote: 'Moreover, the release of thousands of emails from the University of East Anglia’s Climate Research Unit in 2009 showed climate scientists concerned with the lack of recent warming and how to “hide the decline.” The communications showed that whatever the emailers were engaged in, it was not the disinterested pursuit of science.

Another batch of 5,000 emails written by top climate scientists came out in 2011, discussing, among other public-relations matters, how to deal with skeptical editors and how to suppress unfavorable data. It is a measure of the intellectual corruption of the mainstream media that this wasn’t the scandal of the century. But then again I forget, “the science is settled.”

Ah, yes, Climategate.  His ultimate "evidence."  Yet there's no mention of the multiple separate investigations into the illegal hacking into university computers and dumping of cherry-picked and, in some instances, edited private e-mails.  Why wasn't Climategate the "scandal of the century" as Gordon wishes it had been?  Could it be because all of the investigations—every single one—cleared the scientists of wrongdoing?  Don't believe me?  Here are the reports from:

• The Independent Climate Change Email Review 
• The House of Commons Science and Technology Committee
• University of East Anglia
• Pennsylvania State University
• The Environmental Protection Agency
• US Department of Commerce Inspector Genera
• National Science Foundation

 Happy reading.

In short, Gordon's argument is based on a cartoon version of how science works, his personal ignorance of climate science, and the long-debunked Climategate conspiracy theory.  What's missing are actual facts and science.