Monthly Archives: June 2023

Comment, English writing

The fall of Affirmative Action

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If I understand it correctly, the supreme court’s ruling yesterday did not demand color blindness in the college admission process.  Rather, it only says colleges should not blindly use skin color as a predictor for a student’s qualifications and fitness.   Nor did the ruling reject in any way the value of diversity, including racial diversity.  Rather, the court merely opined that continuing to pursue this value through Affirmation Action can no longer be justified, partly because it violates the equal-protection clause in the Constitution, and partly because it has injured other people, notably Asian students.

Will Asian students and their parents find it any easier to get into the elite colleges in a post-AA world? I doubt it.   For one thing, elite colleges have many reasons and tools to continue the pursuit of diversity, equity and inclusion. Not explicitly considering race does not mean a “pure” merit-based admission, in the narrow sense of the phrase many Asians have come to understand it.   Second, a post-AA world would still see a large number of admissions be slotted for the kids of alumnus, wealthy donors, and other powerful people on the dean’s mysterious list.   This favoritism, much more than AA ever did, has and will continue to squeeze the room of other applicants, including many Asians. Curiously, Americans seem to hold much less grudges about this injustice.  Finally, the expectation of an easier run would probably attract even more applications to the super competitive colleges, which I am afraid might further drive down the admission rate and, being so obsessively invested in education, Asians probably will feel it more acutely than other groups.

housekeeping, Recent research

Integrated bus-bike system

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After much delay, the last paper Sida and I wrote together came out last week in Transportation Research Part C.   Growing out of the last chapter of Sida’s PhD dissertation, the first draft of the paper was completed before he went back to China in the summer of 2020, at the height of COVID19 pandemic.   In part, the long delay was due to Sida’s transition to his new job at Beijing Jiaotong University.   I am glad he pressed on despite the early setbacks and eventually published the paper  in a descent journal.  Here is the abstract for those who wonder what is an integrated bus-bike system.

Abstract: This paper examines the design of a transit system that integrates a fixed-route bus service and a bike-sharing service. Bike availability – the average probability that a traveller can find a bike at a dock – is modelled as an analytical function of bike utilization rate, which depends on travel demand, bike usage and bike fleet size. The proposed system also recognizes the greater flexibility provided by biking. Specifically, a traveller can choose between the closest bus stop and a more distant stop for access, egress or both. Whether the closest stop is a better choice depends on the relative position of the traveller’s origin and destination, as well as system design parameters. This interdependence complicates the estimation of average system cost, which is conditional on route choice. Using a stylized analysis approach, we construct the optimal design problem as a mixed integer program with a small number of decision variables. Results from our numerical experiments show the integrated bus-bike system promises a modest but consistent improvement over several benchmark systems, especially in poorer cities with lower demand density. We find a large share of travellers, more than 20% in nearly all cases tested, opt not to use the nearest bus stop in an optimally designed system. The system also tends to maintain a high level of bike availability: the probability of finding a bike rarely drops below 90% except in very poor cities.

Book review, English writing

How the world really works

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My former colleague and mentor, Prof. David Boyce, loved Vaclav Smil’s How the World Really Works.  In a short email sent earlier this year, he urged me to read it, adding, “of the nearly 100 books I read this year, this one was the best”.  As encouragement he even mailed a hardcopy to me all the way from his retirement home in Arizona, to my pleasant surprise.  I’ve never heard of Smil before.   According to Wikipedia, he is a prolific and decorated author who counts Bill Gates among his fans.  An immigrant from Czech Republic, he had a PhD in geography but wrote about a wide variety of topics ranging from energy and environment to economics and public policy.

I don’t quite know how to make sense of the book’s seemingly pretentious title. If not for David’s recommendation, the title would probably have turned me away.  Having read the book, I suspect Smil had chosen the title to hide the controversial thesis of the book, which I think is an earnest pushback on the current “mainstream” climate policies and initiatives. Had the book been entitled to reflect this position, however, I imagine many people from the left would reject it out of hand as a manifesto from yet another climate change denier.  Here is Smil’s thesis in a nutshell:

“Complete decarbonization of the global economy by 2050 is now conceivable only at the cost of unthinkable global economic retreat, or as a result of extraordinarily rapid transformations relying on near-miraculous technical advances. But who is going, willingly, to engineer the former while we are still lacking any convincing, practical, affordable global strategy and technical means to pursue the latter?”

Let me first unpack how he reached this conclusion.

Citing Ludwig Boltzmann, Smil argues that free energy (i.e., energy available for conversion) is “the object of struggle for life”.   In the past two centuries, humans have gradually gained access to “a tremendous amount of energy at low cost” from burning fossil fuels.  This has largely transformed life on earth, from scarcity and misery that plagued much of human history to abundance and comfort that so many today had taken for granted.  By 2020, the annual energy consumed by an average person reached 34 GJ, equal to the energy content of about 0.8 tons of crude oil.  If the person would source this amount of energy from physical labor, Smil estimates they would need 60 adult servants working non-stop, day and night.  In affluent countries, this number would increase to approximately 200 to 240.  Clearly, before the energy revolution, only a very small minority could ever hope to avoid hard labor necessary to sustain and advance civilization.  As Thomas Piketty explained in his Capital in 21st Century, in such a world, social inequality was not only inevitable but maybe necessary because “if there had not been a sufficiently wealthy minority, no one would have been able to worry about anything other than survival.” Moreover, “without a fortune it was impossible to live a dignified life”.   Of course, the energy revolution did not eradicate inequality; but living a dignified life and thinking beyond mere survival is no longer the privilege of the super-rich. For this newfound luxury we have the fossil fuel industry to thank.

Central to Smil’s argument is, therefore, the observation that humanity has become deeply dependent on the cheap energy provided by fossil fuels.  The book explores this dependency in the production of electricity, food, industrial materials, and transportation.

  • Although the share of renewable energy (hydropower, solar and wind) in global electricity generation has reached 32% by 2022, fossil fuels (coal and natural gas) remained the dominant source (about 60%). As the uptake of renewables continues, however, the challenge lies not so much in converting solar and wind energy to electricity as in addressing their uneven spatiotemporal distribution.   Tackling this challenge requires the ability to store a massive amount of electricity and transmit it across vast distances. The former is contingent upon a technological breakthrough and the latter, even if we tolerate the cost of transmission, needs expensive infrastructure that currently does not exist. As Peter Nihan pointed out, there is a reason why “95 percent of humanity sources its electricity from power plants less than fifty miles away”.  Indeed, Germany had to keep almost 90% of its fossil fuel power plants as backup despite more than half of the country’s electricity is now generated from renewable sources.
  • The agricultural industries depend on fossil fuels for synthetic fertilizers, among other things (e.g., power for machinery). Smil estimates that more than two thirds of the nitrogen needed for growing crops worldwide is supplied by fertilizers produced from natural gas using the Haber-Bosch process. If we decide to only feed crops by organic wastes, he concluded, more than half of the current global population would be wiped out, and those lucky enough to stick around would struggle to afford regular consumption of meat.  To drive home the crucial importance of fossil fuel to our food supply, Smil painstakingly calculated the life cycle “oil contents” in several staple food items. Perhaps the most memorable example was the tomato grown in the heated greenhouses of Almería, Spain, which consumes more than half liter diesel fuel per kilogram of edible fruit. In contrast, a kilogram of chicken, the most “efficient” meat in terms of energy conversion, can be produced with as little as 0.15 liters of diesel fuel.
  • Smil also surveyed the ubiquitous presence of cement, steel, plastics, and ammonia in our life. The production of these “four pillars of modern civilization”, as he like to call them, relies heavily on energy- and carbon-intensive processes, collectively accounting for about one sixth of the global energy supply and a quarter of all fossil fuel consumption.  Smil asserts that we won’t be able to displace these materials anytime soon given their extensive current utilization. Nor could they be readily decarbonized because their established production processes have no “commercially available and readily deployable mass-scale alternatives”.
  • As for transportation, there are two major obstacles. First, electric motors are still far from a viable substitute to turbofan engines currently powering long-haul aviation.  After all, the energy density of today’s best Li-ion batteries only amounts to about 5% that of jet fuel.  Second, the raw materials needed to build batteries – lithium, cobalt, and nickel, to name a few – may not be able to keep up with the enthusiasm of EV advocates.   To reach a 50% EV market share globally by 2050, Smil estimated that the demand for lithium, cobalt and nickel would grow by a factor of, respectively, 20, 19 and 31.  Take cobalt for example.  A quick Google search shows that, as of now (2022), the world has a cobalt reserve of about 8.3 million tons and an annual production of about 190,000 tons. Per Smil’s estimation, the production of cobalt would rise to nearly 4 million tons in 2050, or nearly half of the entire current reserve.

Having explained why we will be stuck with fossil fuels in the foreseeable future, Smil turned to address what he considered hyperbolic responses to the unfolding climate crisis.  To be sure, Smil is no climate change denier. However, he does raise serious concerns regarding climate science and the way it is being portrayed to mobilize mass action.   Smil tells us the cutting-edge global climate models contributed little to advance our understanding about the greenhouse effect and its long-term consequences.   Instead, the scientific community has been “aware of them for more than 150 years, and in a clear and explicit manner for more than a century”.  He also questions the value of performing long-term forecast with these large, ostensibly sophisticated, and complex models.  Such exercises may produce headlines decorated with impressive numbers.  However, riddled with “layered and often questionable assumptions”, they are little more than “computerized fairy tales”, whose primary function is to help the users
“reinforce their own prejudices or to dismiss plausible alternatives”, rather than reliably informing decision making. Smil’s distaste for complex forecasting models reminds me of Douglas J. Lee who, in his famous Requiem for Large-Scale Models, criticized the development of integrated land use and transportation models for the purpose of infrastructure planning. To explain why a more complex model isn’t necessarily better, Lee wrote,

“Including more components in a model generates the illusion that refinements are being added and uncertainty eliminated, but, in practice, every additional component introduces less that is known than is not known”.

In a nutshell, the climate models cannot really tell us what is going to happen in 30 years and to believe otherwise is “to mistake the science of global warming for the religion of climate change”.  Thus, Smil rejects the grim warning that our fossil-fueled civilization will soon collapse unless we immediately take drastic actions to decarbonize the world economy.   He also dismisses the grandiose claims that technological breakthroughs will somehow save humanity from this impending calamity, if only we have faith in them.  He ruthlessly mocks the “techno-optimists” –– who promised that 80 percent of global energy supply can be decarbonized by 2030, and an economy fueled by 100% renewables actually “needs less energy, costs less, and creates more jobs” –– and likens them to “green hymn” singers.

So, what is Smil for?  First, he prefers steady and mundane strategies to “sudden desperate actions aimed at preventing a catastrophe”. Two specific actions he suggested does make sense: reducing food waste, which shockingly amounts to a third of the overall food supply, and curtailing the ownership of SUVs, whose wide adoption had more than offset in the past decade the decarbonization gains resulting from the slow adoption of EVs.  Second, he wants us to “be agnostic about the distant future”, to admit the limits of our understanding, to “approach all planetary challenges with humility”, and to recognize no amount of planning can assure ultimate success.

Smil likes to build his argument around numbers and facts.  However, absorbing all the numbers can sometimes become such a mental burden that the reader may be distracted from the flow of the book.  Of course, this may be a feature rather than a bug; after all, Smil also wrote a popular book called Numbers Do Not Lie.  The chapter discussing risks and life expectancy seems a little baffling to me: it may be interesting in its own right, but a poor fit for the main theme.   That said, the book is a joy to read overall: Smil writes elegantly, his argument well-construed and his conclusions convincing.  Harsh as his critique of the climate modelers may be, it did resonate with me –– and I am a bit of a modeler myself.  However, I am probably not the kind of audience that Smil intends (need) to win over. To young liberals like AOC and Greta Thunberg, Smil’s even-headed message may be too conservative to swallow.  They might even find his lectures on “how the world really works” nerdy and old-fashioned, if not condescending and insulting.  Many a climate action enthusiast would probably never have time and patience to hear the old man out anyway, as they are so preoccupied by the continuous flow of new bad news that implore them to do something, anything, here and now, and at any cost if necessary.