When are we going to get serious about climate change?

Oct 8, JDN 24578035

Those two storms weren’t simply natural phenomena. We had a hand in creating them.

The EPA doesn’t want to talk about the connection, and we don’t have enough statistical power to really be certain, but there is by now an overwhelming scientific consensus that global climate change will increase hurricane intensity. The only real question left is whether it is already doing so.

The good news is that global carbon emissions are no longer rising. They have been essentially static for the last few years. The bad news is that this is almost certainly too little, too late.

The US is not on track to hit our 2025 emission target; we will probably exceed it by at least 20%.

But the real problem is that the targets themselves are much too high. Most countries have pledged to drop emissions only about 8-10% below their 1990s levels.

Even with the progress we have made, we are on track to exceed the global carbon budget needed to keep warming below 2 C by the year 2040. We have been reducing emission intensity by about 0.8% per year—we need to be reducing it by at least 3% per year and preferably faster. Highly-developed nations should be switching to nuclear energy as quickly as possible; an equitable global emission target requires us to reduce our emissions by 80% by 2050.

At the current rate of improvement, we will overshoot the 2 C warming target and very likely the 3C target as well.

Why aren’t we doing better? There is of course the Tragedy of the Commons to consider: Each individual country acting in its own self-interest will continue to pollute more, as this is the cheapest and easiest way to maintain industrial development. But then if all countries do so, the result is a disaster for us all.
But this explanation is too simple. We have managed to achieve some international cooperation on this issue. The Kyoto protocol has worked; emissions among Kyoto member nations have been reduced by more than 20% below 1990 levels, far more than originally promised. The EU in particular has taken a leadership role in reducing emissions, and has a serious shot at hitting their target of 40% reduction by 2030.

That is a truly astonishing scale of cooperation; the EU has a population of over 500 million people and spans 28 nations. It would seem like doing that should get us halfway to cooperating across all nations and all the world’s people.

But there is a vital difference between the EU and the world as a whole: The tribal paradigm. Europeans certainly have their differences: The UK and France still don’t really get along, everyone’s bitter with Germany about that whole Hitler business, and as the acronym PIIGS emphasizes, the peripheral countries have never quite felt as European as the core Schengen members. But despite all this, there has been a basic sense of trans-national (meta-national?) unity among Europeans for a long time.
For one thing, today Europeans see each other as the same race. That wasn’t always the case. In Medieval times, ethnic categories were as fine as “Cornish” and “Liverpudlian”. (To be fair, there do still exist a handful of Cornish nationalists.) Starting around the 18th cenutry, Europeans began to unite under the heading of “White people”, a classification that took on particular significance during the trans-Atlantic slave trade. But even in the 19th century, “Irish” and “Sicilian” were seen as racial categories. It wasn’t until the 20th century that Europeans really began to think of themselves as one “kind of people”, and not coincidentally it was at the end of the 20th century that the European Union finally took hold.

There is another region that has had a similar sense of unification: Latin America. Again, there are conflicts: There are a lot of nasty stereotypes about Puerto Ricans among Cubans and vice-versa. But Latinos, by and large, think of each other as the same “kind of people”, distinct from both Europeans and the indigenous population of the Americas.

I don’t think it is coincidental that the lowest carbon emission intensity (carbon emissions / GDP PPP) in the world is in Latin America, followed closely by Europe.
And if you had to name right now the most ethnically divided region in the world, what would you say? The Middle East, of course. And sure enough, they have the worst carbon emission intensity. (Of course, oil is an obvious confounding variable here, likely contributing to both.)

Indeed, the countries with the lowest ethnic fractionalization ratings tend to be in Europe and Latin America, and the highest tend to be in the Middle East and Africa.

Even within the United States, political polarization seems to come with higher carbon emissions. When we think of Democrats and Republicans as different “kinds of people”, we become less willing to cooperate on finding climate policy solutions.

This is not a complete explanation, of course. China has a low fractionalization rating but a high carbon intensity, and extremely high overall carbon emissions due to their enormous population. Africa’s carbon intensity isn’t as high as you’d think just from their terrible fractionalization, especially if you exclude Nigeria which is a major oil producer.

But I think there is nonetheless a vital truth here: One of the central barriers to serious long-term solutions to climate change is the entrenchment of racial and national identity. Solving the Tragedy of the Commons requires cooperation, we will only cooperate with those we trust, and we will only trust those we consider to be the same “kind of people”.

You can even hear it in the rhetoric: If “we” (Americans) give up our carbon emissions, then “they” (China) will take advantage of us. No one seems to worry about Alabama exploiting California—certainly no Republican would—despite the fact that in real economic terms they basically do. But people in Alabama are Americans; in other words, they count as actual people. People in China don’t count. If anything, people in California are supposed to be considered less American than people in Alabama, despite the fact that vastly more Americans live in California than Alabama. This mirrors the same pattern where we urban residents are somehow “less authentic” even though we outnumber the rural by four to one.
I don’t know how to mend this tribal division; I very much wish I did. But I do know that simply ignoring it isn’t going to work. We can talk all we want about carbon taxes and cap-and-trade, but as long as most of the world’s people are divided into racial, ethnic, and national identities that they consider to be in zero-sum conflict with one another, we are never going to achieve the level of cooperation necessary for a real permanent solution to climate change.

The temperatures and the oceans rise. United we must stand, or divided we shall fall.

I think I know what the Great Filter is now

Sep 3, JDN 2458000

One of the most plausible solutions to the Fermi Paradox of why we have not found any other intelligent life in the universe is called the Great Filter: Somewhere in the process of evolving from unicellular prokaryotes to becoming an interstellar civilization, there is some highly-probable event that breaks the process, a “filter” that screens out all but the luckiest species—or perhaps literally all of them.

I previously thought that this filter was the invention of nuclear weapons; I now realize that this theory is incomplete. Nuclear weapons by themselves are only an existential threat because they co-exist with widespread irrationality and bigotry. The Great Filter is the combination of the two.

Yet there is a deep reason why we would expect that this is precisely the combination that would emerge in most species (as it has certainly emerged in our own): The rationality of a species is not uniform. Some individuals in a species will always be more rational than others, so as a species increases its level of rationality, it does not do so all at once.

Indeed, the processes of economic development and scientific advancement that make a species more rational are unlikely to be spread evenly; some cultures will develop faster than others, and some individuals within a given culture will be further along than others. While the mean level of rationality increases, the variance will also tend to increase.

On some arbitrary and oversimplified scale where 1 is the level of rationality needed to maintain a hunter-gatherer tribe, and 20 is the level of rationality needed to invent nuclear weapons, the distribution of rationality in a population starts something like this:

Great_Filter_1

Most of the population is between levels 1 and 3, which we might think of as lying between the bare minimum for a tribe to survive and the level at which one can start to make advances in knowledge and culture.

Then, as the society advances, it goes through a phase like this:

Great_Filter_2

This is about where we were in Periclean Athens. Most of the population is between levels 2 and 8. Level 2 used to be the average level of rationality back when we were hunter-gatherers. Level 8 is the level of philosophers like Archimedes and Pythagoras.

Today, our society looks like this:
Great_Filter_3

Most of the society is between levels 4 and 20. As I said, level 20 is the point at which it becomes feasible to develop nuclear weapons. Some of the world’s people are extremely intelligent and rational, and almost everyone is more rational than even the smartest people in hunter-gatherer times, but now there is enormous variation.

Where on this chart are racism and nationalism? Importantly, I think they are above the level of rationality that most people had in ancient times. Even Greek philosophers had attitudes toward slaves and other cultures that the modern KKK would find repulsive. I think on this scale racism is about a 10 and nationalism is about a 12.

If we had managed to uniformly increase the rationality of our society, with everyone gaining at the same rate, our distribution would instead look like this:
Great_Filter_4

If that were the case, we’d be fine. The lowest level of rationality widespread in the population would be 14, which is already beyond racism and nationalism. (Maybe it’s about the level of humanities professors today? That makes them substantially below quantum physicists who are 20 by construction… but hey, still almost twice as good as the Greek philosophers they revere.) We would have our nuclear technology, but it would not endanger our future—we wouldn’t even use it for weapons, we’d use it for power generation and space travel. Indeed, this lower-variance high-rationality state seems to be about what they have the Star Trek universe.

But since we didn’t, a large chunk of our population is between 10 and 12—that is, still racist or nationalist. We have the nuclear weapons, and we have people who might actually be willing to use them.

Great_Filter_5

I think this is what happens to most advanced civilizations around the galaxy. By the time they invent space travel, they have also invented nuclear weapons—but they still have their equivalent of racism and nationalism. And most of the time, the two combine into a volatile mix that results in the destruction or regression of their entire civilization.

If this is right, then we may be living at the most important moment in human history. It may be right here, right now, that we have the only chance we’ll ever get to turn the tide. We have to find a way to reduce the variance, to raise the rest of the world’s population past nationalism to a cosmopolitan morality. And we may have very little time.

What will we do without air travel?

August 6, JDN 2457972

Air travel is incredibly carbon-intensive. Just one round-trip trans-Atlantic flight produces about 1 ton of carbon emissions per passenger. To keep global warming below 2 K, personal carbon emissions will need to be reduced to less than 1.5 tons per person per year by 2050. This means that simply flying from New York to London and back twice in a year would be enough to exceed the total carbon emissions each person can afford if we are to prevent catastrophic global climate change.

Currently about 12% of US transportation-based carbon emissions are attributable to aircraft; that may not sound like a lot, but consider this. Of the almost 5 trillion passenger-miles traveled by Americans each year, only 600 billion are by air, while 60,000 are by public transit. That leaves 4.4 trillion passenger-miles traveled by car. About 60% of US transportation emissions are due to cars, while 88% of US transportation is by car. About 12% of US transportation emissions are due to airplanes, while 12% of US passenger-miles are traveled by airplane. This means that cars produce about 2/3 as much carbon per passenger-mile, even though we tend to fill up airplanes to the brim and most Americans drive alone most of the time.

Moreover, we know how to reduce emissions from cars. We can use hybrid vehicles, we can carpool more, or best of all we can switch to entirely electric vehicles charged off a grid that is driven by solar and nuclear power. It is theoretically possible to make personal emissions from car travel zero. (Though making car manufacturing truly carbon-neutral may not be feasible; electric cars actually produce somewhat more carbon in their production, though not enough to actually make them worse than conventional cars.)

We have basically no idea how to reduce emissions from air travel. Jet engines are already about as efficient as we know how to make them. There are some tweaks to taxi and takeoff procedure that would help a little bit (chiefly, towing the aircraft to the runway instead of taking them there on their own power; also, taking off from longer runways that require lower throttle to achieve takeoff speed). But there’s basically nothing we can do to reduce the carbon emissions of a cruising airliner at altitude. Even very optimistic estimates involving new high-tech alloys, wing-morphing technology, and dramatically improved turbofan engines only promise to reduce emissions by about 30%.

This is something that affects me quite directly; air travel is a major source of my personal carbon footprint, but also the best way I have to visit family back home.
Using the EPA’s handy carbon footprint calculator, I estimate that everything else I do in my entire life produces about 10 tons of carbon emissions per year. (This is actually pretty good, given the US average of 22 tons per person per year. It helps that I’m vegetarian, I drive a fuel-efficient car, and I live in Southern California.)

Using the ICAO’s even more handy carbon footprint calculator for air travel, I estimate that I produce about 0.2 tons for every round-trip economy-class transcontinental flight from California to Michigan. But that doesn’t account for the fact that higher-altitude emissions are more dangerous. If you adjust for this, the net effect is as if I had produced a full half-ton of carbon for each round-trip flight. Therefore, just four round-trip flights per year increases my total carbon footprint by 20%—and again, by itself exceeds what my carbon emissions need to be reduced to by the year 2050.

With this in mind, most ecologists agree that air travel as we know it is simply not sustainable.

The question then becomes: What do we do without it?

One option would be to simply take all the travel we currently do in airplanes, and stop it. For me this would mean no more trips from California to Michigan, except perhaps occasional long road trips for moving and staying for long periods.

This is unappealing, though it is also not as harmful as you might imagine; most of the world’s population has never flown in an airplane. Our estimates of exactly what proportion of people have flown are very poor, but our best guesses are that about 6% of the world’s population flies in any given year, and about 40% has ever flown in their entire life. Statistically, most of my readers are middle-class Americans, and we’re accustomed to flying; about 80% of Americans have flown on an airplane at least once, and about 1/3 of Americans fly at least once a year. But we’re weird (indeed, WEIRD, White, Educated, Industrialized, Rich, and Democratic); most people in the world fly on airplanes rarely, if ever.

Moreover, air travel has only been widely available to the general population, even in the US, for about the last 60 years. Passenger-miles on airplanes in the US have increased by a factor of 20 since just 1960, while car passenger-miles have only tripled and population has only doubled. Most of the human race through most of history has only dreamed of air travel, and managed to survive just fine without it.

It certainly would not mean needing to stop all long-distance travel, though long-distance travel would be substantially curtailed. It would no longer be possible to travel across the country for a one-week stay; you’d have to plan for four or five days of travel in each direction. Traveling from the US to Europe takes about a week by sea, each way. That means planning your trip much further in advance, and taking off a lot more time from work to do it.

Fortunately, trade is actually not that all that dependent on aircraft. The vast majority of shipping is done by sea vessel already, as container ships are simply far more efficient. Shipping by container ship produces only about 2% as much carbon per ton-kilometer as shipping by aircraft. “Slow-steaming”, the use of more ships at lower speeds to conserve fuel, is already widespread, and carbon taxes would further incentivize it. So we need not fear giving up globalized trade simply because we gave up airplanes.

But we can do better than that. We don’t need to give up the chance to travel across the country in a weekend. The answer is high-speed rail.

A typical airliner cruises at about 500 miles per hour. Can trains match that? Not quite, but close. Spain already has an existing commercial high-speed rail line, the AVE, which goes from Madrid to Barcelona at a cruising speed of 190 miles per hour. This is far from the limits of the technology. The fastest train ever built is the L0 series, a Japanese maglev which can maintain a top speed of 375 miles per hour.

This means that if we put our minds to it, we could build a rail line crossing the United States, say from Los Angeles to New York via Chicago, averaging at least 300 miles per hour. That’s a distance of 2800 miles by road (rail should be comparable); so the whole trip should take about 9 and a half hours. This is slower than a flight (unless you have a long layover), but could still make it there and back in the same weekend.

How much would such a rail system cost? Official estimates of the cost of maglev line are about $100 million per mile. This could probably be brought down by technological development and economies of scale, but let’s go with it for now. This means that my proposed LA-NY line would cost $280 billion.

That’s not a small amount of money, to be sure. It’s about the annual cost of ending world hunger forever. It’s almost half the US military budget. It’s about one-third of Obama’s stimulus plan in 2009. It’s about one-fourth Trump’s proposed infrastructure plan (that will probably never happen).

In other words, it’s a large project, but well within the capacity of a nation as wealthy as the United States.

Add in another 500 miles to upgrade the (already-successful) Acela corridor line on the East Coast, and another 800 miles to make the proposed California High-Speed Rail from LA to SF a maglev line, and you’ve increased the cost to $410 billion.
$410 billion is about 2 years of revenue for all US airlines. These lines could replace a large proportion of all US air traffic. So if the maglev system simply charged as much as a plane ticket and carried the same number of passengers, it would pay for itself in a few years. Realistically it would probably be a bit cheaper and carry fewer people, so the true payoff period might be more like 10 years. That is a perfectly reasonable payoff period for a major infrastructure project.

Compare this to our existing rail network, which is pitiful. There are Amtrak lines from California to Chicago; one is the Texas Eagle of 2700 miles, comparable to my proposed LA-NY maglev; the other is the California Zephyr of 2400 miles. Each of them completes one trip in about two and a half daysso a week-long trip is unviable and a weekend trip is mathematically impossible. Over 60 hours on each train, instead of the proposed 9.5 for the same distance. The operating speed is only about 55 miles per hour when we now have technology that could do 300. The Acela Express is our fastest train line with a top speed of 150 miles per hour and average end-to-end speed of 72 miles per hour; and (not coincidentally I think) it is by far the most profitable train line in the United States.

And best of all, the entire rail system could be carbon-neutral. Making the train itself run without carbon emissions is simple; you just run it off nuclear power plants and solar farms. The emissions from the construction and manufacturing would have to be offset, but most of them would be one-time emissions, precisely the sort of thing that it does make sense to offset with reforestation. Realistically some emissions would continue during the processes of repair and maintenance, but these would be far, far less than what the airplanes were producing—indeed, not much more than the emissions from a comparable length of interstate highway.

Let me emphasize, this is all existing technology. Unlike those optimistic forecasts about advanced new aircraft alloys and morphing wings, I’m not talking about inventing anything new here. This is something other countries have already built (albeit on a much smaller scale). I’m using official cost estimates. Nothing about this plan should be infeasible.

Why are we not doing this? We’re choosing not to. Our government has decided to spend on other things instead. Most Americans are quite complacent about climate change, though at least most Americans do believe in it now.

What about transcontinental travel? There we may have no choice but to give up our weekend visits. Sea vessels simply can’t be built as fast as airplanes. Even experimental high-speed Navy ships can’t far exceed 50 knots, which is about 57 miles per hour—highway speed, not airplane speed. A typical container vessel slow-steams at about 12 knots—14 miles per hour.

But how many people travel across the ocean anyway? As I’ve already established, Americans fly more than almost anyone else in the world; but of the 900 million passengers carried in flights in, through, or out of the US, only 200 million were international Some 64% of Americans have never left the United States—never even to Canada or Mexico! Even if we cut off all overseas commercial flights completely, we are affecting a remarkably small proportion of the world’s population.

And of course I wouldn’t actually suggest banning air travel. We should be taxing air travel, in proportion to its effect on global warming; and those funds ought to get us pretty far in paying for the up-front cost of the maglev network.

What can you do as an individual? Ay, there’s the rub. Not much, unfortunately. You can of course support candidates and political campaigns for high-speed rail. You can take fewer flights yourself. But until this infrastructure is built, those of us who live far from our ancestral home will face the stark tradeoff between increasing our carbon footprint and never getting to see our families.

Games as economic simulations—and education tools

Mar 5, JDN 2457818 [Sun]

Moore’s Law is a truly astonishing phenomenon. Now as we are well into the 21st century (I’ve lived more of my life in the 21st century than the 20th now!) it may finally be slowing down a little bit, but it has had quite a run, and even this could be a temporary slowdown due to economic conditions or the lull before a new paradigm (quantum computing?) matures. Since at least 1975, the computing power of an individual processor has doubled approximately every year and a half; that means it has doubled over 25 times—or in other words that it has increased by a factor of over 30 million. I now have in my pocket a smartphone with several thousand times the processing speed of the guidance computer of the Saturn V that landed on the Moon.

This meteoric increase in computing power has had an enormous impact on the way science is done, including economics. Simple theoretical models that could be solved by hand are now being replaced by enormous simulation models that have to be processed by computers. It is now commonplace to devise models with systems of dozens of nonlinear equations that are literally impossible to solve analytically, and just solve them iteratively with computer software.

But one application of this technology that I believe is currently underutilized is video games.

As a culture, we still have the impression that video games are for children; even games like Dragon Age and Grand Theft Auto that are explicitly for adults (and really quite inappropriate for children!) are viewed as in some sense “childish”—that no serious adult would be involved with such frivolities. The same cultural critics who treat Shakespeare’s vagina jokes as the highest form of art are liable to dismiss the poignant critique of war in Call of Duty: Black Ops or the reflections on cultural diversity in Skyrim as mere puerility.

But video games are an art form with a fundamentally greater potential than any other. Now that graphics are almost photorealistic, there is really nothing you can do in a play or a film that you can’t do in a video game—and there is so, so much more that you can only do in a game.
In what other medium can we witness the spontaneous emergence and costly aftermath of a war? Yet EVE Online has this sort of event every year or so—just today there was a surprise attack involving hundreds of players that destroyed thousands of hours’—and dollars’—worth of starships, something that has more or less become an annual tradition. A few years ago there was a massive three-faction war that destroyed over $300,000 in ships and has now been commemorated as “the Bloodbath of B-R5RB”.
Indeed, the immersion and interactivity of games present an opportunity to do nothing less than experimental macroeconomics. For generations it has been impossible, or at least absurdly unethical, to ever experimentally manipulate an entire macroeconomy. But in a video game like EVE Online or Second Life, we can now do so easily, cheaply, and with little or no long-term harm to the participants—and we can literally control everything in the experiment. Forget the natural resource constraints and currency exchange rates—we can change the laws of physics if we want. (Indeed, EVE‘s whole trade network is built around FTL jump points, and in Second Life it’s a basic part of the interface that everyone can fly like Superman.)

This provides untold potential for economic research. With sufficient funding, we could build a game that would allow us to directly test hypotheses about the most fundamental questions of economics: How do governments emerge and maintain security? How is the rule of law sustained, and when can it be broken? What controls the value of money and the rate of inflation? What is the fundamental cause of unemployment, and how can it be corrected? What influences the rate of technological development? How can we maximize the rate of economic growth? What effect does redistribution of wealth have on employment and output? I envision a future where we can directly simulate these questions with thousands of eager participants, varying the subtlest of parameters and carrying out events over any timescale we like from seconds to centuries.

Nor is the potential of games in economics limited to research; it also has enormous untapped potential in education. I’ve already seen in my classes how tabletop-style games with poker chips can teach a concept better in a few minutes than hours of writing algebra derivations on the board; but custom-built video games could be made that would teach economics far better still, and to a much wider audience. In a well-designed game, people could really feel the effects of free trade or protectionism, not just on themselves as individuals but on entire nations that they control—watch their GDP numbers go down as they scramble to produce in autarky what they could have bought for half the price if not for the tariffs. They could see, in real time, how in the absence of environmental regulations and Pigovian taxes the actions of millions of individuals could despoil our planet for everyone.

Of course, games are fundamentally works of fiction, subject to the Fictional Evidence Fallacy and only as reliable as their authors make them. But so it is with all forms of art. I have no illusions about the fact that we will never get the majority of the population to regularly read peer-reviewed empirical papers. But perhaps if we are clever enough in the games we offer them to play, we can still convey some of the knowledge that those papers contain. We could also update and expand the games as new information comes in. Instead of complaining that our students are spending time playing games on their phones and tablets, we could actually make education into games that are as interesting and entertaining as the ones they would have been playing. We could work with the technology instead of against it. And in a world where more people have access to a smartphone than to a toilet, we could finally bring high-quality education to the underdeveloped world quickly and cheaply.

Rapid growth in computing power has given us a gift of great potential. But soon our capacity will widen even further. Even if Moore’s Law slows down, computing power will continue to increase for awhile yet. Soon enough, virtual reality will finally take off and we’ll have even greater depth of immersion available. The future is bright—if we can avoid this corporatist cyberpunk dystopia we seem to be hurtling toward, of course.

Debunking the Simulation Argument

Oct 23, JDN 2457685

Every subculture of humans has words, attitudes, and ideas that hold it together. The obvious example is religions, but the same is true of sports fandoms, towns, and even scientific disciplines. (I would estimate that 40-60% of scientific jargon, depending on discipline, is not actually useful, but simply a way of exhibiting membership in the tribe. Even physicists do this: “quantum entanglement” is useful jargon, but “p-brane” surely isn’t. Statisticians too: Why say the clear and understandable “unequal variance” when you could show off by saying “heteroskedasticity”? In certain disciplines of the humanities this figure can rise as high as 90%: “imaginary” as a noun leaps to mind.)

One particularly odd idea that seems to define certain subcultures of very intelligent and rational people is the Simulation Argument, originally (and probably best) propounded by Nick Bostrom:

This paper argues that at least one of the following propositions is true: (1) the human species is very likely to go extinct before reaching a “posthuman” stage; (2) any posthuman civilization is extremely unlikely to run a significant number of simulations of their evolutionary history (or variations thereof); (3) we are almost certainly living in a computer simulation.

In this original formulation by Bostrom, the argument actually makes some sense. It can be escaped, because it makes some subtle anthropic assumptions that need to be considered more carefully (in short, there could be ancestor-simulations but we could still know we aren’t in one); but it deserves to be taken seriously. Indeed, I think proposition (2) is almost certainly true, and proposition (1) might be as well; thus I have no problem accepting the disjunction.

Of course, the typical form of the argument isn’t nearly so cogent. In popular outlets as prestigious as the New York Times, Scientific American and the New Yorker, the idea is simply presented as “We are living in a simulation.” The only major outlet I could find that properly presented Bostrom’s disjunction was PBS. Indeed, there are now some Silicon Valley billionaires who believe the argument, or at least think it merits enough attention to be worth funding research into how we might escape the simulation we are in. (Frankly, even if we were inside a simulation, it’s not clear that “escaping” would be something worthwhile or even possible.)

Yet most people, when presented with this idea, think it is profoundly silly and a waste of time.

I believe this is the correct response. I am 99.9% sure we are not living in a simulation.

But it’s one thing to know that an argument is wrong, and quite another to actually show why; in that respect the Simulation Argument is a lot like the Ontological Argument for God:

However, as Bertrand Russell observed, it is much easier to be persuaded that ontological arguments are no good than it is to say exactly what is wrong with them.

To resolve this problem, I am writing this post (at the behest of my Patreons) to provide you now with a concise and persuasive argument directly against the Simulation Argument. No longer will you have to rely on your intuition that it can’t be right; you actually will have compelling logical reasons to reject it.

Note that I will not deny the core principle of cognitive science that minds are computational and therefore in principle could be simulated in such a way that the “simulations” would be actual minds. That’s usually what defenders of the Simulation Argument assume you’re denying, and perhaps in many cases it is; but that’s not what I’m denying. Yeah, sure, minds are computational (probably). There’s still no reason to think we’re living in a simulation.

To make this refutation, I should definitely address the strongest form of the argument, which is Nick Bostrom’s original disjunction. As I already noted, I believe that the disjunction is in fact true; at least one of those propositions is almost certainly correct, and perhaps two of them.

Indeed, I can tell you which one: Proposition (2). That is, I see no reason whatsoever why an advanced “posthuman” species would want to create simulated universes remotely resembling our own.


First of all, let’s assume that we do make it that far and posthumans do come into existence. I really don’t have sufficient evidence to say this is so, and the combination of millions of racists and thousands of nuclear weapons does not bode particularly well for that probability. But I think there is at least some good chance that this will happen—perhaps 10%?—so, let’s concede that point for now, and say that yes, posthumans will one day exist.

To be fair, I am not a posthuman, and cannot say for certain what beings of vastly greater intelligence and knowledge than I might choose to do. But since we are assuming that they exist as the result of our descendants more or less achieving everything we ever hoped for—peace, prosperity, immortality, vast knowledge—one thing I think I can safely extrapolate is that they will be moral. They will have a sense of ethics and morality not too dissimilar from our own. It will probably not agree in every detail—certainly not with what ordinary people believe, but very likely not with what even our greatest philosophers believe. It will most likely be better than our current best morality—closer to the objective moral truth that underlies reality.

I say this because this is the pattern that has emerged throughout the advancement of civilization thus far, and the whole reason we’re assuming posthumans might exist is that we are projecting this advancement further into the future. Humans have, on average, in the long run, become more intelligent, more rational, more compassionate. We have given up entirely on ancient moral concepts that we now recognize to be fundamentally defective, such as “witchcraft” and “heresy”; we are in the process of abandoning others for which some of us see the flaws but others don’t, such as “blasphemy” and “apostasy”. We have dramatically expanded the rights of women and various minority groups. Indeed, we have expanded our concept of which beings are morally relevant, our “circle of concern”, from only those in our tribe on outward to whole nations, whole races of people—and for some of us, as far as all humans or even all vertebrates. Therefore I expect us to continue to expand this moral circle, until it encompasses all sentient beings in the universe. Indeed, on some level I already believe that, though I know I don’t actually live in accordance with that theory—blame me if you will for my weakness of will, but can you really doubt the theory? Does it not seem likely that this it the theory to which our posthuman descendants will ultimately converge?

If that is the case, then posthumans would never make a simulation remotely resembling the universe I live in.

Maybe not me in particular, for I live relatively well—though I must ask why the migraines were really necessary. But among humans in general, there are many millions who live in conditions of such abject squalor and suffering that to create a universe containing them can only be counted as the gravest of crimes, morally akin to the Holocaust.

Indeed, creating this universe must, by construction, literally include the Holocaust. Because the Holocaust happened in this universe, you know.

So unless you think that our posthuman descendants are monstersdemons really, immortal beings of vast knowledge and power who thrive on the death and suffering of other sentient beings, you cannot think that they would create our universe. They might create a universe of some sort—but they would not create this one. You may consider this a corollary of the Problem of Evil, which has always been one of the (many) knockdown arguments against the existence of God as depicted in any major religion.

To deny this, you must twist the simulation argument quite substantially, and say that only some of us are actual people, sentient beings instantiated by the simulation, while the vast majority are, for lack of a better word, NPCs. The millions of children starving in southeast Asia and central Africa aren’t real, they’re just simulated, so that the handful of us who are real have a convincing environment for the purposes of this experiment. Even then, it seems monstrous to deceive us in this way, to make us think that millions of children are starving just to see if we’ll try to save them.

Bostrom presents it as obvious that any species of posthumans would want to create ancestor-simulations, and to make this seem plausible he compares to the many simulations we already create with our current technology, which we call “video games”. But this is such a severe equivocation on the word “simulation” that it frankly seems disingenuous (or for the pun perhaps I should say dissimulation).

This universe can’t possibly be a simulation in the sense that Halo 4 is a simulation. Indeed, this is something that I know with near-perfect certainty, for I am a sentient being (“Cogito ergo sum” and all that). There is at least one actual sentient person here—me—and based on my observations of your behavior, I know with quite high probability that there are many others as well—all of you.

Whereas, if I thought for even a moment there was even a slight probability that Halo 4 contains actual sentient beings that I am murdering, I would never play the game again; indeed I think I would smash the machine, and launch upon a global argumentative crusade to convince everyone to stop playing violent video games forevermore. If I thought that these video game characters that I explode with virtual plasma grenades were actual sentient people—or even had a non-negligible chance of being such—then what I am doing would be literally murder.

So whatever else the posthumans would be doing by creating our universe inside some vast computer, it is not “simulation” in the sense of a video game. If they are doing this for amusement, they are monsters. Even if they are doing it for some higher purpose such as scientific research, I strongly doubt that it can be justified; and I even more strongly doubt that it could be justified frequently. Perhaps once or twice in the whole history of the civilization, as a last resort to achieve some vital scientific objective when all other methods have been thoroughly exhausted. Furthermore it would have to be toward some truly cosmic objective, such as forestalling the heat death of the universe. Anything less would not justify literally replicating thousands of genocides.

But the way Bostrom generates a nontrivial probability of us living in a simulation is by assuming that each posthuman civilization will create many simulations similar to our own, so that the prior probability of being in a simulation is so high that it overwhelms the much higher likelihood that we are in the real universe. (This a deeply Bayesian argument; of that part, I approve. In Bayesian reasoning, the likelihood is the probability that we would observe the evidence we do given that the theory is true, while the prior is the probability that the theory is true, before we’ve seen any evidence. The probability of the theory actually being true is proportional to the likelihood multiplied by the prior.) But if the Foundation IRB will only approve the construction of a Synthetic Universe in order to achieve some cosmic objective, then the prior probability is something like 2/3, or 9/10; and thus it is no match whatsoever for the some 10^12 evidence in favor of this being actual reality.

Just what is this so compelling likelihood? That brings me to my next point, which is a bit more technical, but important because it’s really where the Simulation Argument truly collapses.

How do I know we aren’t in a simulation?

The fundamental equations of the laws of nature do not have closed-form solutions.

Take a look at the Schrodinger Equation, the Einstein field equations, the Navier-Stokes Equations, even Maxwell’s Equations (which are relatively well-behaved all things considered). These are second-order partial differential equations all, extremely complex to solve. They are all defined over continuous time and space, which has uncountably many points in every interval (though there are some physicists who believe that spacetime may be discrete on the order of 10^-44 seconds.) Not one of them has a general closed-form solution, by which I mean a formula that you could just plug in numbers for the parameters on one side of the equation and output an answer on the other. (x^3 + y^3 = 3 is not a closed-form solution, but y = (3 – x^3)^(1/3) is.) They have such exact solutions in certain special cases, but in general we can only solve them approximately, if at all.

This is not particularly surprising if you assume we’re in the actual universe. I have no particular reason to think that the fundamental laws underlying reality should be of a form that is exactly solvable to minds like my own, or even solvable at all in any but a trivial sense. (They must be “solvable” in the sense of actually resulting in something in particular happening at any given time, but that’s all.)

But it is extremely surprising if you assume we’re in a universe that is simulated by posthumans. If posthumans are similar to us, but… more so I guess, then when they set about to simulate a universe, they should do so in a fashion not too dissimilar from how we would do it. And how would we do it? We’d code in a bunch of laws into a computer in discrete time (and definitely not with time-steps of 10^-44 seconds either!), and those laws would have to be encoded as functions, not equations. There could be many inputs in many different forms, perhaps even involving mathematical operations we haven’t invented yet—but each configuration of inputs would have to yield precisely one output, if the computer program is to run at all.

Indeed, if they are really like us, then their computers will probably only be capable of one core operation—conditional bit flipping, 1 to 0 or 0 to 1 depending on some state—and the rest will be successive applications of that operation. Bit shifts are many bit flips, addition is many bit shifts, multiplication is many additions, exponentiation is many multiplications. We would therefore expect the fundamental equations of the simulated universe to have an extremely simple functional form, literally something that can be written out as many successive steps of “if A, flip X to 1” and “if B, flip Y to 0”. It could be a lot of such steps mind you—existing programs require billions or trillions of such operations—but one thing it could never be is a partial differential equation that cannot be solved exactly.

What fans of the Simulation Argument seem to forget is that while this simple set of operations is extremely general, capable of generating quite literally any possible computable function (Turing proved that), it is not capable of generating any function that isn’t computable, much less any equation that can’t be solved into a function. So unless the laws of the universe can actually be reduced to computable functions, it’s not even possible for us to be inside a computer simulation.

What is the probability that all the fundamental equations of the universe can be reduced to computable functions? Well, it’s difficult to assign a precise figure of course. I have no idea what new discoveries might be made in science or mathematics in the next thousand years (if I did, I would make a few and win the Nobel Prize). But given that we have been trying to get closed-form solutions for the fundamental equations of the universe and failing miserably since at least Isaac Newton, I think that probability is quite small.

Then there’s the fact that (again unless you believe some humans in our universe are NPCs) there are 7.3 billion minds (and counting) that you have to simulate at once, even assuming that the simulation only includes this planet and yet somehow perfectly generates an apparent cosmos that even behaves as we would expect under things like parallax and redshift. There’s the fact that whenever we try to study the fundamental laws of our universe, we are able to do so, and never run into any problems of insufficient resolution; so apparently at least this planet and its environs are being simulated at the scale of nanometers and femtoseconds. This is a ludicrously huge amount of data, and while I cannot rule out the possibility of some larger universe existing that would allow a computer large enough to contain it, you have a very steep uphill battle if you want to argue that this is somehow what our posthuman descendants will consider the best use of their time and resources. Bostrom uses the video game comparison to make it sound like they are just cranking out copies of Halo 917 (“Plasma rifles? How quaint!”) when in fact it amounts to assuming that our descendants will just casually create universes of 10^50 particles running over space intervals of 10^-9 meters and time-steps of 10^-15 seconds that contain billions of actual sentient beings and thousands of genocides, and furthermore do so in a way that somehow manages to make the apparent fundamental equations inside those universes unsolvable.

Indeed, I think it’s conservative to say that the likelihood ratio is 10^12—observing what we do is a trillion times more likely if this is the real universe than if it’s a simulation. Therefore, unless you believe that our posthuman descendants would have reason to create at least a billion simulations of universes like our own, you can assign a probability that we are in the actual universe of at least 99.9%.

As indeed I do.

Alien invasions: Could they happen, and could we survive?

July 30, JDN 2457600

alien-invasion

It’s not actually the top-grossing film in the US right now (that would be The Secret Life of Pets), but Independence Day: Resurgence made a quite respectable gross of $343 million worldwide, giving it an ROI of 108% over its budget of $165 million. It speaks to something deep in our minds—and since most of the money came from outside the US, apparently not just Americans, though it is a deeply American film—about the fear, but perhaps also the excitement, of a possible alien invasion.

So, how likely are alien invasions anyway?

Well, first of all, how likely are aliens?

One of the great mysteries of astronomy is the Fermi Paradox: Everything we know about astronomy, biology, and probability tells us that there should be, somewhere out in the cosmos, a multitude of extraterrestrial species, and some of them should even be intelligent enough to form civilizations and invent technology. So why haven’t we found any clear evidence of any of them?

Indeed, the Fermi Paradox became even more baffling in just the last two years, as we found literally thousands of new extrasolar planets, many of them quite likely to be habitable. More extrasolar planets have been found since 2014 than in all previous years of human civilization. Perhaps this is less surprising when we remember that no extrasolar planets had ever been confirmed before 1992—but personally I think that just makes it this much more amazing that we are lucky enough to live in such a golden age of astronomy.

The Drake equation was supposed to tell us how probable it is that we should encounter an alien civilization, but the equation isn’t much use to us because so many of its terms are so wildly uncertain. Maybe we can pin down how many planets there are soon, but we still don’t know what proportion of planets can support life, what proportion of those actually have life, or above all what proportion of ecosystems ever manage to evolve a technological civilization or how long such a civilization is likely to last. All possibilities from “they’re everywhere but we just don’t notice or they actively hide from us” to “we are actually the only ones in the last million years” remain on the table.

But let’s suppose that aliens do exist, and indeed have technology sufficient to reach our solar system. Faster-than-light capability would certainly do it, but it isn’t strictly necessary; with long lifespans, cryonic hibernation, or relativistic propulsion aliens could reasonably expect to travel at least between nearby stars within their lifetimes. The Independence Day aliens appear to have FTL travel, but interestingly it makes the most sense if they do not have FTL communication—it took them 20 years to get the distress call because it was sent at lightspeed. (Or perhaps the ansible was damaged in the war, and they fell back to a lightspeed emergency system?) Otherwise I don’t quite get why it would take the Queen 20 years to deploy her personal battlecruiser after the expeditionary force she sent was destroyed—maybe she was just too busy elsewhere to bother with our backwater planet? What did she want from our planet again?

That brings me to my next point: Just what motivation would aliens have for attacking us? We often take it for granted that if aliens exist, and have the capability to attack us, they would do so. But that really doesn’t make much sense. Do they just enjoy bombarding primitive planets? I guess it’s possible they’re all sadistic psychopaths, but it seems like any civilization stable enough to invent interstellar travel has got to have some kind of ethical norms. Maybe they see us as savages or even animals, and are therefore willing to kill us—but that still means they need a reason.

Another idea, taken seriously in V and less so in Cowboys & Aliens, is that there is some sort of resource we have that they want, and they’re willing to kill us to get it. This is probably such a common trope because it has been a common part of human existence; we are very familiar with people killing other people in order to secure natural resources such as gold, spices, or oil. (Indeed, to some extent it continues to this day.)

But this actually doesn’t make a lot of sense on an interstellar scale. Certainly water (V) and gold (Cowboys & Aliens) are not things they would have even the slightest reason to try to claim from an inhabited planet, as comets are a better source of water and asteroids are a better source of gold. Indeed, almost nothing inorganic could really be cost-effective to obtain from an inhabited planet; far easier to just grab it from somewhere that won’t fight back, and may even have richer veins and lower gravity.

It’s possible they would want something organic—lumber or spices, I guess. But I’m not sure why they’d want those things, and it seems kind of baffling that they wouldn’t just trade if they really want them. I’m sure we’d gladly give up a great deal of oregano and white pine in exchange for nanotechnology and FTL. I guess I could see this happening because they assume we’re too stupid to be worth trading with, or they can’t establish reliable means of communication. But one of the reasons why globalization has succeeded where colonialism failed is that trade is a lot more efficient than theft, and I find it unlikely that aliens this advanced would have failed to learn that lesson.

Media that imagines they’d enslave us makes even less sense; slavery is wildly inefficient, and they probably have such ludicrously high productivity that they are already coping with a massive labor glut. (I suppose maybe they send off unemployed youths to go conquer random planets just to give them something to do with their time? Helps with overpopulation too.)

I actually thought Independence Day: Resurgence did a fairlygood job of finding a resource that is scarce enough to be worth fighting over while also not being something we would willingly trade. Spoiler alert, I suppose:

Molten cores. Now, I haven’t the foggiest what one does with molten planet cores that somehow justifies the expenditure of all that energy flying between solar systems and digging halfway through planets with gigantic plasma drills, but hey, maybe they are actually tremendously useful somehow. They certainly do contain huge amounts of energy, provided you can extract it efficiently. Moreover, they are scarce; of planets we know about, most of them do not have molten cores. Earth, Venus, and Mercury do, and we think Mars once did; but none of the gas giants do, and even if they did, it’s quite plausible that the Queen’s planet-cracker drill just can’t drill that far down. Venus sounds like a nightmare to drill, so really the only planet I’d expect them to extract before Earth would be Mercury. And maybe they figured they needed both cores to justify the trip, in which case it would make sense to hit the inhabited planet first so we don’t have time to react and prepare our defenses. (I can’t imagine we’d take giant alien ships showing up and draining Mercury’s core lying down.) I’m imagining the alien economist right now, working out the cost-benefit analysis of dealing with Venus’s superheated atmosphere and sulfuric acid clouds compared to the cost of winning a war against primitive indigenous apes with nuclear missiles: Well, doubling our shield capacity is cheaper than covering the whole ship in sufficient anticorrosive, so I guess we’ll go hit the ape planet. (They established in the first film that their shields can withstand direct hits from nukes—the aliens came prepared.)

So, maybe killing us for our resources isn’t completely out of the question, but it seems unlikely.

Another possibility is religious fanaticism: Every human culture has religion in some form, so why shouldn’t the aliens? And if they do, it’s likely radically different from anything we believe. If they become convinced that our beliefs are not simply a minor nuisance but an active threat to the holy purity of the galaxy, they could come to our system on a mission to convert or destroy at any cost; and since “convert” seems very unlikely, “destroy” would probably become their objective pretty quickly. It wouldn’t have to make sense in terms of a cost-benefit analysis—fanaticism doesn’t have to make sense at all. The good news here is that any culture fanatical enough to randomly attack other planets simply for believing differently from them probably won’t be cohesive enough to reach that level of technology. (Then again, we somehow managed a world with both ISIS and ICBMs.)

Personally I think there is a far more likely scenario for alien invasions, and that is benevolent imperialism.

Why do I specify “benevolent”? Because if they aren’t interested in helping us, there’s really no reason for them to bother with us in the first place. But if their goal is to uplift our civilization, the only way they can do that is by interacting with us.

Now, note that I use the word “benevolent”, not the word “beneficent”. I think they would have to desire to make our lives better—but I’m not so convinced they actually would make our lives better. In our own history, human imperialism was rarely benevolent in the first place, but even where it was, it was even more rarely actually beneficent. Their culture would most likely be radically different from our own, and what they think of as improvements might seem to us strange, pointless, or even actively detrimental. But don’t you see that the QLX coefficient is maximized if you convert all your mountains into selenium extractors? (This is probably more or less how Native Americans felt when Europeans started despoiling their land for things called “coal” and “money”.) They might even try to alter us biologically to be more similar to them: But haven’t you always wanted tentacles? Hands are so inefficient!

Moreover, even if their intentions were good and their methods of achieving them were sound, it’s still quite likely that we would violently resist. I don’t know if humans are a uniquely rebellious species—let’s hope not, lest the aliens be shocked into overreacting when we rebel—but in general humans do not like being ruled over and forced to do things, even when those rulers are benevolent and the things they are forced to do are worth doing.

So, I think the most likely scenario for a war between humans and aliens is that they come in and start trying to radically reorganize our society, and either because their demands actually are unreasonable, or at least because we think they are, we rebel against their control.

Then what? Could we actually survive?

The good news is: Yes, we probably could.

If aliens really did come down trying to extract our molten core or something, the movies are all wrong: We’d have basically no hope. It really makes no sense at all that we could win a full-scale conflict with a technologically superior species if they were willing to exterminate us. Indeed, if what they were after didn’t depend upon preserving local ecology, their most likely mode of attack is to arrive in the system and immediately glass the planet. Nuclear weapons are already available to us for that task; if they’re more advanced they might have antimatter bombs, relativistic kinetic warheads, or even something more powerful still. We might be all dead before we even realized what was happening, or they might destroy 90% of us right away and mop up the survivors later with little difficulty.

If they wanted something that required ecological stability (I shall henceforth dub this the “oregano scenario”), yet weren’t willing to trade for some reason, then they wouldn’t unleash full devastation, and we’d have the life-dinner principle on our side: The hare runs for his life, but the fox only runs for her dinner. So if the aliens are trying to destroy us to get our delicious spices, we have a certain advantage from the fact that we are willing to win at essentially any cost, while at some point that alien economist is going to run the numbers and say, “This isn’t cost-effective. Let’s cut our losses and hit another system instead.”

If they wanted to convert us to their religion, well, we’d better hope enough people convert, because otherwise they’re going to revert to, you guessed it, glass the planet. At least this means they would probably at least try to communicate first, so we’d have some time to prepare; but it’s unlikely that even if their missionaries spent decades trying to convert us we could seriously reduce our disadvantage in military technology during that time. So really, our best bet is to adopt the alien religion. I guess what I’m really trying to say here is “All Hail Xemu.”

But in the most likely scenario that their goal is actually to make our lives better, or at least better as they see it, they will not be willing to utilize their full military capability against us. They might use some lethal force, especially if they haven’t found reliable means of nonlethal force on sufficient scale; but they aren’t going to try to slaughter us outright. Maybe they kill a few dissenters to set an example, or fire into a crowd to disperse a riot. But they are unlikely to level a city, and they certainly wouldn’t glass the entire planet.

Our best bet would probably actually be nonviolent resistance, as this has a much better track record against benevolent imperialism. Gandhi probably couldn’t have won a war against Britain, but he achieved India’s independence because he was smart enough to fight on the front of public opinion. Likewise, even with one tentacle tied behind their backs by their benevolence, the aliens would still probably be able to win any full-scale direct conflict; but if our nonviolent resistance grew strong enough, they might finally take the hint and realize we don’t want their so-called “help”.

So, how about someone makes that movie? Aliens come to our planet, not to kill us, but to change us, make us “better” according to their standards. QLX coefficients are maximized, and an intrepid few even get their tentacles installed. But the Resistance arises, and splits into two factions: One tries to use violence, and is rapidly crushed by overwhelming firepower, while the other uses nonviolent resistance. Ultimately the Resistance grows strong enough to overthrow the alien provisional government, and they decide to cut their losses and leave our planet. Then, decades later, we go back to normal, and wonder if we made the right decision, or if maybe QLX coefficients really were the most important thing after all.

[The image is released under a CC0 copyleft from Pixabay.]

Should we give up on growth?

JDN 2457572

Recently I read this article published by the Post Carbon Institute, “How to Shrink the Economy without Crashing It”, which has been going around environmentalist circles. (I posted on Facebook that I’d answer it in more detail, so here goes.)

This is the far left view on climate change, which is wrong, but not nearly as wrong as even the “mainstream” right-wing view that climate change is not a serious problem and we should continue with business as usual. Most of the Republicans who ran for President this year didn’t believe in using government action to fight climate change, and Donald Trump doesn’t even believe it exists.
This core message of the article is clearly correct:

We know this because Global Footprint Network, which methodically tracks the relevant data, informs us that humanity is now using 1.5 Earths’ worth of resources.

We can temporarily use resources faster than Earth regenerates them only by borrowing from the future productivity of the planet, leaving less for our descendants. But we cannot do this for long.

To be clear, “using 1.5 Earths” is not as bad as it sounds; spending is allow to exceed income at times, as long as you have reason to think that future income will exceed future spending, and this is true not just of money but also of natural resources. You can in fact “borrow from the future”, provided you do actually have a plan to pay it back. And indeed there has been some theoretical work by environmental economists suggesting that we are rightly still in the phase of net ecological dissaving, and won’t enter the phase of net ecological saving until the mid-21st century when our technology has made us two or three times as productive. This optimal path is defined by a “weak sustainability” condition where total real wealth never falls over time, so any natural wealth depleted is replaced by at least as much artificial wealth.

Of course some things can’t be paid back; while forests depleted can be replanted, if you drive species to extinction, only very advanced technology could restore them. And we are driving thousands of species to extinction every single year. Even if we should be optimally dissaving, we are almost certainly depleting natural resources too fast, and depleting natural resources that will be difficult if not impossible to later restore. In that sense, the Post Carbon Institute is right: We must change course toward ecological sustainability.

Unfortunately, their specific ideas of how to do so leave much to be desired. Beyond ecological sustainability, they really argue for two propositions: one is radical but worth discussing, but the other is totally absurd.

The absurd claim is that we should somehow force the world to de-urbanize and regress into living in small farming villages. To show this is a bananaman and not a strawman, I quote:

8. Re-localize. One of the difficulties in the transition to renewable energy is that liquid fuels are hard to substitute. Oil drives nearly all transportation currently, and it is highly unlikely that alternative fuels will enable anything like current levels of mobility (electric airliners and cargo ships are non-starters; massive production of biofuels is a mere fantasy). That means communities will be obtaining fewer provisions from far-off places. Of course trade will continue in some form: even hunter-gatherers trade. Re-localization will merely reverse the recent globalizing trade trend until most necessities are once again produced close by, so that we—like our ancestors only a century ago—are once again acquainted with the people who make our shoes and grow our food.

9. Re-ruralize. Urbanization was the dominant demographic trend of the 20th century, but it cannot be sustained. Indeed, without cheap transport and abundant energy, megacities will become increasingly dysfunctional. Meanwhile, we’ll need lots more farmers. Solution: dedicate more societal resources to towns and villages, make land available to young farmers, and work to revitalize rural culture.

First of all: Are electric cargo ships non-starters? The Ford-class aircraft carrier is electric, specifically nuclear. Nuclear-powered cargo ships would raise a number of issues in terms of practicality, safety, and regulation, but they aren’t fundamentally infeasible. Massive efficient production of biofuels is a fantasy as long as the energy to do it is provided by coal power, but not if it’s provided by nuclear. Perhaps this author’s concept of “infeasible” really just means “infeasible if I can’t get over my irrational fear of nuclear power”. Even electric airliners are not necessarily out of the question; NASA has been experimenting with electric aircraft.

The most charitable reading I can give of this (in my terminology of argument “men”, I’m trying to make a banana out of iron), is as promoting slightly deurbanizing and going back to more like say the 1950s United States, with 64% of people in cities instead of 80% today. Even then this makes less than no sense, as higher urbanization is associated with lower per-capita ecological impact, which frankly shouldn’t even be surprising because cities have such huge economies of scale. Instead of everyone needing a car to get around in the suburbs, we can all share a subway system in the city. If that subway system is powered by a grid of nuclear, solar, and wind power, it could produce essentially zero carbon emissions—which is absolutely impossible for rural or suburban transportation. Urbanization is also associated with slower population growth (or even population decline), and indeed the reason population growth is declining is that rising standard of living and greater urbanization have reduced birth rates and will continue to do so as poor countries reach higher levels of development. Far from being a solution to ecological unsustainability, deurbanization would make it worse.

And that’s not even getting into the fact that you would have to force urban white-collar workers to become farmers, because if we wanted to be farmers we already would be (the converse is not as true), and now you’re actually talking about some kind of massive forced labor-shift policy like the Great Leap Forward. Normally I’m annoyed when people accuse environmentalists of being totalitarian communists, but in this case, I think the accusation might be onto something.

Moving on, the radical but not absurd claim is that we must turn away from economic growth and even turn toward economic shrinkage:

One way or another, the economy (and here we are talking mostly about the economies of industrial nations) must shrink until it subsists on what Earth can provide long-term.

[…]

If nothing is done deliberately to reverse growth or pre-adapt to inevitable economic stagnation and contraction, the likely result will be an episodic, protracted, and chaotic process of collapse continuing for many decades or perhaps centuries, with innumerable human and non-human casualties.

I still don’t think this is right, but I understand where it’s coming from, and like I said it’s worth talking about.

The biggest mistake here lies in assuming that GDP is directly correlated to natural resource depletion, so that the only way to reduce natural resource depletion is to reduce GDP. This is not even remotely true; indeed, countries vary almost as much in their GDP-per-carbon-emission ratio as they do in their per-capita GDP. As usual, #ScandinaviaIsBetter; Norway and Sweden produce about $8,000 in GDP per ton of carbon, while the US produces only about $2,000 per ton. Both poor and rich countries can be found among both the inefficient and the efficient. Saudi Arabia is very rich and produces about $900 per ton, while Liberia is exceedingly poor and produces about $800 per ton. I already mentioned how Norway produces $8,000 per ton, and they are as rich as Saudi Arabia. Yet above them is Mali, which produces almost $11,000 per ton, and is as poor as Liberia. Other notable facts: France is head and shoulders above the UK and Germany at almost $6000 per ton instead of $4300 and $3600 respectively—because France runs almost entirely on nuclear power.

So the real conclusion to draw from this is not that we need to shrink GDP, but that we need to make GDP more like how they do it in Norway or at least how they do it in France, rather than how we do in the US, and definitely not how they do it in Saudi Arabia. Total world emissions are currently about 36 billion tons per year, producing about $108 trillion in GDP, averaging about $3,000 of GDP per ton of carbon emissions. If we could raise the entire world to the ecological efficiency of Norway, we could double world GDP and still be producing less CO2 than we currently are. Turning the entire planet into a bunch of Norways would indeed raise CO2 output, by about a factor of 2; but it would raise standard of living by a factor of 5, and indeed bring about a utopian future with neither war nor hunger. Compare this to the prospect of cutting world GDP in half, but producing it as inefficiently as in Saudi Arabia: This would actually increase global CO2 emissions, almost as much as turning every country into Norway.

But ultimately we will in fact need to slow down or even end economic growth. I ran a little model for you, which shows a reasonable trajectory for global economic growth.

This graph shows the growth rate in productivity slowly declining, along with a much more rapidly declining GDP growth:

Solow_growth

This graph shows the growth trajectory for total real capital and GDP:

Solow_capital

And finally, this is the long-run trend for GDP graphed on a log scale:

Solow_logGDP

The units are arbitrary, though it’s not unreasonable to imagine them as being years and hundreds of dollars in per-capita GDP. If that is indeed what you imagine them to be, my model shows us the Star Trek future: In about 300 years, we rise from a per-capita GDP of $10,000 to one of $165,000—from a world much like today to a world where everyone is a millionaire.

Notice that the growth rate slows down a great deal fairly quickly; by the end of 100 years (i.e., the end of the 21st century), growth has slowed from its peak over 10% to just over 2% per year. By the end of the 300-year period, the growth rate is a crawl of only 0.1%.

Of course this model is very simplistic, but I chose it for a very specific reason: This is not a radical left-wing environmentalist model involving “limits to growth” or “degrowth”. This is the Solow-Swan model, the paradigm example of neoclassical models of economic growth. It is sometimes in fact called simply “the neoclassical growth model”, because it is that influential. I made one very small change from the usual form, which was to assume that the rate of productivity growth would decline exponentially over time. Since productivity growth is exogenous to the model, this is a very simple change to make; it amounts to saying that productivity-enhancing technology is subject to diminishing returns, which fits recent data fairly well but could be totally wrong if something like artificial intelligence or neural enhancement ever takes off.

I chose this because many environmentalists seem to think that economists have this delusional belief that we can maintain a rate of economic growth equal to today indefinitely. David Attenborough famously said “Anyone who believes in indefinite growth in anything physical, on a physically finite planet, is either mad – or an economist.”

Another physicist argued that if we increase energy consumption 2.3% per year for 400 years, we’d literally boil the Earth. Yes, we would, and no economist I know of believes that this is what will happen. Economic growth doesn’t require energy growth, and we do not think growth can or should continue indefinitely—we just think it can and should continue a little while longer. We don’t think that a world standard of living 1000 times as good as Norway is going to happen; we think that a world standard of living equal to Norway is worth fighting for.

Indeed, we are often the ones trying to explain to leaders that they need to adapt to slower growth rates—this is particularly a problem in China, where nationalism and groupthink seems to have convinced many people in China that 7% annual growth is the result of some brilliant unique feature of the great Chinese system, when it is in fact simply the expected high growth rate for an economy that is very poor and still catching up by establishing a capital base. (It’s not so much what they are doing right now, as what they were doing wrong before. Just as you feel a lot better when you stop hitting yourself in the head, countries tend to grow quite fast after they transition out of horrifically terrible economic policy—and it doesn’t get much more terrible than Mao.) Even a lot of the IMF projections are now believed to be too optimistic, because they didn’t account for how China was fudging the numbers and rapidly depleting natural resources.

Some of the specific policies recommended in the article are reasonable, while others go to far.

1. Energy: cap, reduce, and ration it. Energy is what makes the economy go, and expanded energy consumption is what makes it grow. Climate scientists advocate capping and reducing carbon emissions to prevent planetary disaster, and cutting carbon emissions inevitably entails reducing energy from fossil fuels. However, if we aim to shrink the size of the economy, we should restrain not just fossil energy, but all energy consumption. The fairest way to do that would probably be with tradable energy quotas.

I strongly support cap-and-trade on fossil fuels, but I can’t support it on energy in general, unless we get so advanced that we’re seriously concerned about significantly altering the entropy of the universe. Solar power does not have negative externalities, and therefore should not be taxed or capped.

The shift to renewable energy sources is a no-brainer, and I know of no ecologist and few economists who would disagree.

This one is rich, coming from someone who goes on to argue for nonsensical deurbanization:

However, this is a complicated process. It will not be possible merely to unplug coal power plants, plug in solar panels, and continue with business as usual: we have built our immense modern industrial infrastructure of cities, suburbs, highways, airports, and factories to take advantage of the unique qualities and characteristics of fossil fuels.

How will we make our industrial infrastructure run off a solar grid? Urbanization. When everything is in one place, you can use public transportation and plug everything into the grid. We could replace the interstate highway system with a network of maglev lines, provided that almost everyone lived in major cities that were along those lines. We can’t do that if people move out of cities and go back to being farmers.

Here’s another weird one:

Without continued economic growth, the market economy probably can’t function long. This suggests we should run the transformational process in reverse by decommodifying land, labor, and money.

“Decommodifying money”? That’s like skinning leather or dehydrating water. The whole point of money is that it is a maximally fungible commodity. I support the idea of a land tax to provide a basic income, which could go a long way to decommodifying land and labor; but you can’t decommodify money.

The next one starts off sounding ridiculous, but then gets more reasonable:

4. Get rid of debt. Decommodifying money means letting it revert to its function as an inert medium of exchange and store of value, and reducing or eliminating the expectation that money should reproduce more of itself. This ultimately means doing away with interest and the trading or manipulation of currencies. Make investing a community-mediated process of directing capital toward projects that are of unquestioned collective benefit. The first step: cancel existing debt. Then ban derivatives, and tax and tightly regulate the buying and selling of financial instruments of all kinds.

No, we’re not going to get rid of debt. But should we regulate it more? Absolutely. A ban on derivatives is strong, but shouldn’t be out of the question; it’s not clear that even the most useful derivatives (like interest rate swaps and stock options) bring more benefit than they cause harm.

The next proposal, to reform our monetary system so that it is no longer based on debt, is one I broadly agree with, though you need to be clear about how you plan to do that. Positive Money’s plan to make central banks democratically accountable, establish full-reserve banking, and print money without trying to hide it in arcane accounting mechanisms sounds pretty good to me. Going back to the gold standard or something would be a terrible idea. The article links to a couple of “alternative money theorists”, but doesn’t explain further.

Sooner or later, we absolutely will need to restructure our macroeconomic policy so that 4% or even 2% real growth is no longer the expectation in First World countries. We will need to ensure that constant growth isn’t necessary to maintain stability and full employment.

But I believe we can do that, and in any case we do not want to stop global growth just yet—far from it. We are now on the verge of ending world hunger, and if we manage to do it, it will be from economic growth above all else.