Reduce Carbon-Dioxide Emissions?

If It Takes Much Time or Expense, Probably Not

If what you’ve heard about a climate crisis has you spending much effort on reducing your carbon-dioxide emissions, you may want to reconsider your practices in light of a comment recently made by physicist Steven E. Koonin.  The author of Unsettled: What Climate Science Tells Us, What It Doesn’t, and Why It Matters, he made the comment during a public discussion with former Indiana governor and current Purdue University president Mitch Daniels. 

What Dr. Koonin said is that it doesn’t take an expert to recognize the kinds of things his book points out, such as that climate change’s net economic impact is projected to be modest.  In this post we will therefore make our own, non-expert assessment of whether de-carbonization is worth the effort.  But first we’ll discuss the controversy that Mr. Daniels’ invitation to Dr. Koonin provoked.

Dr. Koonin’s stature certainly justified the invitation.  After teaching physics for over thirty years at Caltech, nine of them as provost, Dr. Koonin became chief scientist at BP plc, where he focused on advancing renewable energy, and he subsequently became undersecretary for science in the Obama administration’s Department of Energy.  As that background might suggest, he had long marinated in the consensus view that global warming presents an existential threat. 

But he dug into the underlying science more deeply when the American Physical Society (“APS”) thereafter chose him to lead a review of its statement on climate change.  And in the course of that exercise he convened a workshop that included not only the usual “consensus” views but also some more-independent voices.  As he later recounted, “I came away from the APS workshop not only surprised but shaken by the realization that climate science was far less mature than I had supposed.”

So he embarked upon further investigation, of which Unsettled is among the results.  Like books such as Bjorn Lomborg’s False Alarm and Michael Shellenberger’s Apocalypse Never, Dr. Koonin’s Unsettled doesn’t espouse Naptown Numbers’ view that on balance carbon dioxide emissions are actually beneficial.  His book is based instead on the “official” science, i.e., the research that underpins the U.S. National Climate Assessments and the Assessment Reports of the Intergovernmental Panel on Climate Change (“IPCC”).  But what his book finds is that there’s a yawning chasm between how the research is presented what it actually says. 

Predictably for a book whose message is uncongenial to the prevailing, more-apocalyptic view, Unsettled attracted considerable criticism.  Dr. Koonin has handled that criticism ably, however, and in three consecutive posts about his detractors Naptown Numbers has shown how among careful readers such criticism’s poor quality could actually make Dr. Koonin’s position more compelling. 

One of the detractors, for example, was climate-textbook author Raymond Pierrehumbert, who characterized as “the most shameless cherry-picking” Dr. Koonin’s observation that the rate of sea-level rise now is only about the same as it was in the early Twentieth Century—when humans emitted only a small fraction of what we currently do.  The question obviously posed by that observation is how, when the rate of sea-level rise was just as high before carbon-dioxide emissions became significant, climate scientists can be so sure that carbon-dioxide emissions are its primary cause now. 

Dr. Pierrehumbert’s critique gave the impression that the rate of sea-level rise had increased more or less monotonically: “[T]he sea level trend was .8 millimeters of rise per year from 1870 to 1924, 1.9 millimeters per year from 1925 to 1992, and 3.2 millimeters per year from 1993 to 2014—i.e., the rate has actually quadrupled since preindustrial times.”  As a previous post’s Fig. 4 illustrated, though, Dr. Pierrehumbert’s argument violated the cardinal time-series rule against mixing trend durations.  What sea-level data actually show is that the rate of increase has been alternately increasing and decreasing for over a hundred years—with, again, same-length trends in the early Twentieth Century about as high they are today.  That Dr. Koonin’s critics had to resort to such deceptive tactics is a tribute to the strength of his work. 

In the face of such tactics’ inadequacy, some critics have tried to deny Dr. Koonin a forum altogether.  Purdue Climate Change Research Center director Jeffrey Dukes, for example, argued as follows against allowing Dr. Koonin to speak:

On issues like this, when we’re trying to make important plans about the future, and plans that set signals for our up-and-coming generation about what the future is going to look like, we need leadership. It’s clear, at Purdue, the leader is very much our president, Mitch Daniels. It’s clear that Mitch Daniels does not have climate change as a high priority on his list.

Although Dr. Dukes in particular seems to fear scrutiny of the “official” science, his was not the only opposition to permitting such open discussion.  Engineering professor Alice Pawley, for instance, contended that “Academic freedom . . . is not the right to say what one likes on a college campus. It is the right for research to be judged by the standards of their field, not by politicians or university presidents.”    

But Mr. Daniels had written in a Washington Post op-ed that Unsettled is “probably the year’s most important book.”  And in one of the few recent victories that open inquiry has enjoyed on campuses he accordingly went ahead with the planned discussion.  In the course of that discussion he directly addressed the efforts to de-platform Dr. Koonin:

In the last few days, I know an entirely sincere member of our community said that it’s not a good idea to have Dr. Koonin here, because it might leave the impression of uncertainty.  Which, you know, I hope we will all reflect on as really an unfortunately wrong-headed idea of what a university is about across all its disciplines, hard science or not. 

He followed that statement with a quote from the great Twentieth Century physicist Richard Feynman: “If you thought that science was certain, well, that is just an error on your part.” 

Dr. Koonin’s visit thereby occasioned an important message about the nature of science and the academic enterprise generally.  Somewhat before Mr. Daniels delivered that message, moreover, Dr. Koonin had made a statement particularly relevant to the present post: that according to the research cited by the IPCC “we’re looking at about a 4% impact on either the U.S. or the global economy in 2100 for a warming as much as 6°.”  Even with a temperature increase of a whopping 6°F, that is, people in a world that will likely be four times a rich as today’s will have suffered a growth delay of only about two years. 

If we ignore such context—as Dr. Koonin’s detractors apparently would have us do—we run the risk of adopting climate policies whose cost exceeds that of whatever global warming we thereby avoid.  In that connection Dr. Koonin mentioned the work of William D. Nordhaus, who won a Nobel Prize in 2018 for his work on effective climate solutions.  In particular, a model developed by Dr. Nordhaus showed that expending too much emissions-reduction effort too soon would be counterproductive because of the resultant economic disruption and immature-technology deployment.

In a November 11, 2021, Wall Street Journal piece, Copenhagen Consensus president Bjorn Lomborg provided the following plot to illustrate the Nordhaus model’s output:

What his plot shows is that through the rest of this century expending much more than about $20 trillion worldwide on emissions reduction and thereby reducing the temperature increase by much more than 1.1°F would do more harm than good.  Blindly taking whatever actions we think will reduce carbon-dioxide emissions can therefore cause both governmental and personal waste.

Consider in the latter connection a hypothetical Indianapolis teacher who ordinarily uses her car for the 3.2-mile commute from her Riley Towers home to her job at St. Richard’s School.  Her current commute is fairly convenient; the drive takes only 10 minutes, and she has free parking at work.  But she knows her car emits carbon dioxide, so because of the purported climate crisis she decides to do what she can. 

To that end she consults Google Maps and finds that taking IndyGo Route 19 would involve 10 minutes for the actual bus ride as well as 10 additional minutes of walking to and from the bus stops.  Adding 7.5 minutes (half of Route 19’s 15-minute rush-hour headway) for the average wait at the bus stop, she estimates that her commute would take 17.5 minutes more by bus than it does by car.  That’s a little inconvenient, she thinks, but in a climate crisis everyone must do his bit.

Too often our reasoning goes no deeper than that.  Although proponents of Indianapolis’s benchmarking ordinance tricked out their advocacy with a lot of financial-savings claims, for example, it’s clear that a principal motivation for the measure’s penalty provisions was climate-change fear. "Climate change is here,” Councilman John Barth was quoted as saying in connection with its passage, “and the time to act is now.”   Sure, we may have heard that scientists aren’t all in agreement.  But we aren’t scientists.  So, when we’re told that 97% of scientists favor taking action now, that’s what we do.

Decisions made on such bases are likely to be ill-considered.  For one thing, the 97% figure bruited about by people like Dr. Dukes grossly misrepresents the facts.  More to the point here, that type of decision defers excessively to scientists even though in many cases the issue really turns on matters of logic and math that aren’t scientists’ exclusive province at all. 

And, sure enough, attendees at the Purdue event were greeted by flyers on their seats pointing out that Dr. Koonin isn’t a climate scientist.  Now, as the author of Computational Physics, Dr. Koonin is probably better qualified to evaluate the models at the heart of many climate predictions than, say, a forestry or biology major who calls himself a climate scientist.  For that matter, Dr. Koonin actually has published in the climate field.  As he explained, though, credentials are really beside the point in this case:

The kinds of things I point out in the book, you don’t have to be an expert in. . . .  I like the following analogy: If I were to order carpet for a room that’s 8 × 10, and the carpet guy, who is an expert, came back and said, ‘You need 200 square feet of carpeting,’ I would know that something’s wrong.  And those are the kinds of errors that I point out in the book.

In other words, intelligent laymen are often perfectly capable of judging between opposing claims that scientists may make.  If recognition of that fact were greater, more of us might go beyond mere qualitative considerations to a more-quantitative balancing of costs and benefits. 

In our hypothetical teacher’s case such balancing could start with the cost: her lost time.  Assigning the lost time a dollar value is straightforward if our teacher would otherwise have spent it in $35-per-hour algebra tutoring.  And it’s not self-evident that the time she loses is any less valuable if she would instead have spent it on reading to her pre-schooler.  But that’s a debatable point, and the lost time’s value may be particularly questionable if our teacher would otherwise have spent the time binge-watching re-runs of The Real Housewives of Beverly Hills.  We nonetheless need to assign the lost time some value, and we’re probably not overstating it too much if for the sake of discussion we peg it at $5 per lost hour. 

That $5 per lost hour works out to $1.46 for the 17.5 minutes the teacher would lose by taking the bus.  Gasoline combustion produces 19.6 pounds of carbon dioxide per gallon, so losing that $1.46 worth of time enables the teacher to avoid having her 24-mpg car emit (3.2 mi ÷ 24 mi/gal × 19.6 lb/gal ≈) 2.6 pounds of carbon dioxide.

So how do we put a value on that 2.6 pounds of emissions avoidance?  Well, it has been proposed that a carbon tax based on Dr. Nordhaus’s work should increase gradually from $37 to $271 per metric ton between now and the year 2100.  Although there are good reasons for inferring from the plot above that $37 overstates the optimal initial value, the value we’ll adopt for our evaluation is the even higher $51 per metric ton that the Biden administration has placed on the “social cost” of emitting carbon dioxide.

The Biden-administration figure translates to ($51/t ÷ 2204.6 lb/t ≈) 2.3¢ per pound.  This implies that the teacher’s 2.6 pounds of emissions avoidance is worth approximately the (2.3¢/lb × 2.6 lb ≈) 6¢ represented in the plot above by the left bar’s tiny top segment.  By taking the bus, that is, our hypothetical teacher expends $1.46 worth of her time for 6¢ worth of climate benefit.  Choices like that make us poorer, and we’re more likely to make such poor choices if we’re denied the type of context that Dr. Koonin’s book provides.

Of course, our hypothetical teacher’s situation isn’t necessarily representative of commuting decisions generally.  Also, we left out considerations such as bus fare and car costs.  And most people would probably disagree in one way or another with the $5-per-hour value we placed on the teacher’s lost time.  But that admittedly simplistic example does suffice to illustrate the following point: emissions avoidance can be a relatively insignificant benefit.

We’ll now illustrate the same point with another example, one that deals with a choice between a $43K all-electric 0.25-kWh/mi Tesla and a $26K conventional 32-mpg Honda Accord.  Again we’ll simplify: we’ll ignore the extra time that charging Teslas takes, for instance, as well as the greater quantity of emissions their manufacture requires.  We’ll restrict our attention just to fueling, charging, and post-manufacturing social costs.

If gasoline costs $3 per gallon and electricity costs 10¢ per kilowatt-hour, then over the course of 100,000 miles the ($3/gal ÷ 32 mpg – 0.25 kWh/mi × 10¢/kWh ≈) 6.9¢-per-mile cost difference between gasoline and electricity yields about $6,900 savings for the Tesla.  That reduces the net cost difference from $17,000 to $10,100.  As we’ll now see, this $10,100 buys very little climate benefit. 

In Indianapolis the power company emits about a pound of carbon dioxide for every kilowatt-hour delivered to the socket.  So in 100,000 miles of driving the (19.6 lb/gal ÷ 32 mpg – 1.0 lb/kWh × 0.25 kWh/mi ≈) 0.36-pound-per-mile emissions difference between the two car models amounts to about 36,000 pounds of emissions savings for the Tesla.  At $51 per metric ton this means that the buyer gets a mere $840 in climate benefit in return for that $10,100—which could have gone toward things like kids’ braces, replacing the roof, and paying off student loans. 

A final example will be city-bus purchases.  In a recent Indianapolis Business Journal report that IndyGo had bought some hybrid- and conventional-diesel buses it was stated that the hybrids use 25% less fuel than the conventional diesels.  Over its 524,000-mile life a 3.6-mpg conventional diesel bus would therefore burn 36,400 gallons more diesel fuel than a hybrid, and burning a gallon of diesel fuel produces 22.4 pounds of carbon dioxide.  The resultant 815,000-pound difference in emissions therefore implies an $18,900 difference in social cost. 

We arrived at that $18,900 figure by assuming the 25% emissions reduction that the 25% mileage difference implies; the report’s presumably erroneous claim of 75% less “carbon” would instead imply a $56,600 difference.   Neither figure approaches the $378,633 sticker-price difference implied by the report that IndyGo bought 27 hybrid-diesel buses for $25.8 million and 13 conventional-diesel buses for $7.5 million.  And the $127K the hybrid would save on fuel at $3.50 per gallon doesn’t make up the difference, as the plot below indicates. 

The bottom segment of that plot’s right-hand bar represents the average price implied by a recent all-electric-vehicle purchase, and the segment above it is based on assuming that the bus’s electricity consumption is 2.5 kilowatt-hours per mile.  The resultant total is somewhat greater than it would be for most electric buses, which are more often forty feet long instead of IndyGo’s sixty and aren’t designed for as great a range.  But the plot does validly illustrate that social costs are so small that they should rarely drive the decision.

That’s not the impression we get from the climate scientists that the press quotes, however.  As Dr. Koonin pointed out, much of the press coverage we get results from collusion by a large portion of the fourth estate to present only one side of the climate issue.  To the near-exclusion of more-sober views we therefore get people like Texas A&M professor Andrew Dessler telling us that “in order to . . . avoid these really bad impacts later in the century we have to stop emitting greenhouse gases now.”  We rarely hear that what Dr. Dessler calls “really bad impacts” may be less costly than some of the things we’re likely to do to prevent them.  

We non-scientists would therefore be well-advised to take with a grain of salt the pronouncements of media darlings like Dr. Dessler, who has called Dr. Koonin a “climate flat-earther.”  A side-by-side comparison of Dr. Dessler’s views on wind and solar power with those of a logical non-scientist, for example, makes it painfully clear that what scientists say isn’t always logical—or even factual.

In a world of limited resources, the time and money we spend on avoiding carbon-dioxide emissions will not be unavailable for things like medical research.  The cost of prematurely abandoning fossil fuels could therefore be to deprive our grandchildren of, say, a cure for Alzheimer’s.  While such a possibility is highly speculative it’s no more fanciful than some of the predictions that we get from the climate establishment.  So we should be careful not to be stampeded by wild climate claims into taking actions that may later prove wasteful.