nuclear energy

Green New Deal Part 2: How do we get to net-zero carbon emissions?

pnrj public policy , , , , , , ,

Apr 14 JDN 2458588

I said in my post last week that the Green New Deal has “easy parts”, “hard parts”, and “very hard parts”, and discussed one of the “easy parts”: increased investment in infrastructure. Next week I’ll talk about another “easy part”, guaranteeing education and healthcare.

Today is the most important “hard part”: Reducing our net carbon emissions to zero—or even less.

“Meeting 100 percent of the power demand in the United States through clean, renewable, and zero-emission energy sources.”

“Overhauling transportation systems in the United States to eliminate pollution and greenhouse gas emissions from the transportation sector as much as is technologically feasible, including through investment in – (i) zero-emission vehicle infrastructure and manufacturing; (ii) clean, affordable, and accessible public transportation; and (iii) high-speed rail.”

“Spurring massive growth in clean manufacturing in the United States and removing pollution and greenhouse gas emissions from manufacturing and industry as much as is technologically feasible.”

“Working collaboratively with farmers and ranchers in the United States to eliminate pollution and greenhouse gas emissions from the agricultural sector as much as is technologically feasible.”

There have been huge expansions in solar and wind power generation, which are now cheaper than coal, nuclear, and hydroelectric, on a par with natural gas, and only outcompeted by geothermal. As a result of this dramatic increase in renewable energy production, electric power is no longer the largest source of carbon emissions in the United States; it is now second to transportation.
Policy clearly matters here: While total US carbon emissions were trending downward during the Obama administration, they began trending back upward once Trump took office. Even under Obama, they were not trending down fast enough to realistically meet the Paris Agreement targets. Only 14 states are on track to meet those targets, and they are all hard-Blue states except for Virginia and North Carolina. Unsurprisingly, the most carbon-efficient states are New York and California; yet even our emissions (about 9 tonnes per person per year, about twice the world average) are still far too high.
Of course the US is not alone in failing to meet the targets; in the EU, only three countries (Sweden, France, and Germany) are on track to hit the Paris targets. How did they do it? Germany has managed to do it mainly by expanding wind power, but for most countries, the fastest route to zero-carbon electricity is clearly nuclear power.
Germany has been foolishly phasing out their nuclear capacity, but it’s still 11% of their generation; Sweden’s grid is 40% nuclear; and France has a whopping 72% of their grid on nuclear (no other country comes close). The US grid is about 20% nuclear, which isn’t bad; but if California for instance had not phased out half of our nuclear generation since 2001, we could have taken out 15,000 GWh/yr of natural gas generation instead. At least we did basically eliminate coal and oil power in California, so that’s good.
How much would it cost to convert the entire US electricity grid to renewables and nuclear by 2050? Estimates vary widely, but a good ballpark figure is about $20 trillion.
Let’s not kid ourselves: That is a lot. It’s almost an entire year of the whole US economy. It would be enough to establish a permanent fund to end world hunger almost ten times over. Inflation-adjusted, it’s five times the total amount spent by the US in the Second World War.
Completely re-doing our entire electricity generation system is a project on a scale we’ve really never attempted before. It would be very difficult and very expensive.
But is it feasible? Yes, it’s entirely feasible. Assuming our real GDP grows at a paltry 2% per year between now and 2050, the total economic output of the United States during that period will be almost $1 quadrillion. $20 trillion is only 2% of that. Since the top 1% get about 20% of the income, this means that we could raise enough revenue for this project by simply raising the tax rate on the top 1% by 10 percentage points—which would still make the top income tax rate substantially lower than what we had as recently as the 1970s.
Unfortunately, converting the electricity grid is only part of the story. We also need to make radical changes in our transportation system—switching from airplanes to high-speed rail, and converting cars either to electric cars or public transit systems. Trains are really the best bet, but rail systems have a high up-front cost to build.
Even state-of-the-art high-speed rail systems just can’t be a jet airliner for speed. The best high-speed rail systems can cruise at about 250 kph, while a cruising Boeing 737 can easily exceed 800 kph. We’re just going to have to get used to our long-distance trips taking longer. Even 250 kph is a lot better than the 100 kph you’d probably average driving (not counting stops), which is also about the speed that most current US trains get—far worse than what they have in Europe or even China.
Then we have to deal with the other sources of carbon emissions, like manufacturing and agriculture. It’s simply not realistic to expect that we will actually produce zero carbon emissions; instead our goal needs to be net zero, which means we’ll need some way of pulling carbon out of the air.
To some extent, this is easier than it sounds: Reforestation is a very easy, efficient way of pulling carbon out of the air. Unfortunately it is also very slow, and can only be done in appropriate climates. To really pull enough carbon out of the air fast enough, we’re going to need industrial carbon sequestration or some form of geoengineering—right now iron seeding looks like the most promising candidate, but it could only compensate for about 1/6 of current carbon emissions. Solar geoengineering could do more—but at a very high cost, since we’re talking about pumping poisonous chemicals into the air in order to block out sunlight.
The reason we need to do this is essentially that we have waited too long: Had we started the process of converting the whole grid to renewables in the 1970s like we should have, we wouldn’t need such desperate measures now. But we didn’t, so here we are.
Estimates of how much it will cost to do all this vary even more widely, to the point where I’m hesitant to even put a number on it. But it seems likely that in addition to the $20 trillion for the electric grid, it will probably be something like another $30 trillion to do everything else that is necessary. But the global damage from climate change is estimated to be as much as $3.3 trillion per year—so a total of over $100 trillion over 30 years. Spending $50 trillion to save $100 trillion doesn’t sound like such a bad deal, does it?

Nuclear power is safe. Why don’t people like it?

pnrj ethics, heuristics and biases, public policy , , , , , , , , , , , , , , , , , , , , ,

Sep 24, JDN 2457656

This post will have two parts, corresponding to each sentence. First, I hope to convince you that nuclear power is safe. Second, I’ll try to analyze some of the reasons why people don’t like it and what we might be able to do about that.

Depending on how familiar you are with the statistics on nuclear power, the idea that nuclear power is safe may strike you as either a completely ridiculous claim or an egregious understatement. If your primary familiarity with nuclear power safety is via the widely-publicized examples of Chernobyl, Three Mile Island, and more recently Fukushima, you may have the impression that nuclear power carries huge, catastrophic risks. (You may also be confusing nuclear power with nuclear weapons—nuclear weapons are indeed the greatest catastrophic risk on Earth today, but equating the two is like equating automobiles and machine guns because both of them are made of metal and contain lubricant, flammable materials, and springs.)

But in fact nuclear energy is astonishingly safe. Indeed, even those examples aren’t nearly as bad as people have been led to believe. Guess how many people died as a result of Three Mile Island, including estimated increased cancer deaths from radiation exposure?

Zero. There are zero confirmed deaths and the consensus estimate of excess deaths caused by the Three Mile Island incident by all causes combined is zero.

What about Fukushima? Didn’t 10,000 people die there? From the tsunami, yes. But the nuclear accident resulted in zero fatalities. If anything, those 10,000 people were killed by coal—by climate change. They certainly weren’t killed by nuclear.

Chernobyl, on the other hand, did actually kill a lot of people. Chernobyl caused 31 confirmed direct deaths, as well as an estimated 4,000 excess deaths by all causes. On the one hand, that’s more than 9/11; on the other hand, it’s about a month of US car accidents. Imagine if people had the same level of panic and outrage at automobiles after a month of accidents that they did at nuclear power after Chernobyl.

The vast majority of nuclear accidents cause zero fatalities; other than Chernobyl, none have ever caused more than 10. Deepwater Horizon killed 11 people, and yet for some reason Americans did not unite in opposition against ever using oil (or even offshore drilling!) ever again.

In fact, even that isn’t fair to nuclear power, because we’re not including the thousands of lives saved every year by using nuclear instead of coal and oil.

Keep in mind, the WHO estimates 10 to 100 million excess deaths due to climate change over the 21st century. That’s an average of 100,000 to 1 million deaths every year. Nuclear power currently produces about 11% of the world’s energy, so let’s do a back-of-the-envelope calculation for how many lives that’s saving. Assuming that additional climate change would be worse in direct proportion to the additional carbon emissions (which is conservative), and assuming that half that energy would be replaced by coal or oil (also conservative, using Germany’s example), we’re looking at about a 6% increase in deaths due to climate change if all those nuclear power plants were closed. That’s 6,000 to 60,000 lives that nuclear power plants save every year.

I also haven’t included deaths due to pollution—note that nuclear power plants don’t pollute air or water whatsoever, and only produce very small amounts of waste that can be quite safely stored. Air pollution in all its forms is responsible for one in eight deaths worldwide. Let me say that again: One in eight of all deaths in the world is caused by air pollution—so this is on the order of 7 million deaths per year, every year. We burn our way to a biannual Holocaust. Most of this pollution is actually caused by burning wood—fireplaces, wood stoves, and bonfires are terrible for the air—and many countries would actually see a substantial reduction in their toxic pollution if they switched to oil or even coal in favor of wood. But a large part of that pollution is caused by coal, and a nontrivial amount is caused by oil. Coal-burning factories and power plants are responsible for about 1 million deaths per year in China alone. Most of that pollution could be prevented if those power plants were nuclear instead.

Factor all that in, and nuclear power currently saves tens if not hundreds of thousands of lives per year, and expanding it to replace all fossil fuels could save millions more. Indeed, a more precise estimate of the benefits of nuclear power published a few years ago in Environmental Science and Technology is that nuclear power plants have saved some 1.8 million human lives since their invention, putting them on a par with penicillin and the polio vaccine.

So, I hope I’ve convinced you of the first proposition: Nuclear power plants are safe—and not just safe, but heroic, in fact one of the greatest life-saving technologies ever invented. So, why don’t people like them?

Unfortunately, I suspect that no amount of statistical data by itself will convince those who still feel a deep-seated revulsion to nuclear power. Even many environmentalists, people who could be nuclear energy’s greatest advocates, are often opposed to it. I read all the way through Naomi Klein’s This Changes Everything and never found even a single cogent argument against nuclear power; she simply takes it as obvious that nuclear power is “more of the same line of thinking that got us in this mess”. Perhaps because nuclear power could be enormously profitable for certain corporations (which is true; but then, it’s also true of solar and wind power)? Or because it also fits this narrative of “raping and despoiling the Earth” (sort of, I guess)? She never really does explain; I’m guessing she assumes that her audience will simply share her “gut feeling” intuition that nuclear power is dangerous and untrustworthy. One of the most important inconvenient truths for environmentalists is that nuclear power is not only safe, it is almost certainly our best hope for stopping climate change.

Perhaps all this is less baffling when we recognize that other heroic technologies are often also feared or despised for similarly bizarre reasons—vaccines, for instance.

First of all, human beings fear what we cannot understand, and while the human immune system is certainly immensely complicated, nuclear power is based on quantum mechanics, a realm of scientific knowledge so difficult and esoteric that it is frequently used as the paradigm example of something that is hard to understand. (As Feynman famously said, “I think I can safely say that nobody understands quantum mechanics.”) Nor does it help that popular treatments of quantum physics typically bear about as much resemblance to the actual content of the theory as the X-Men films do to evolutionary biology, and con artists like Deepak Chopra take advantage of this confusion to peddle their quackery.

Nuclear radiation is also particularly terrifying because it is invisible and silent; while a properly-functioning nuclear power plant emits less ionizing radiation than the Capitol Building and eating a banana poses substantially higher radiation risk than talking on a cell phone, nonetheless there is real danger posed by ionizing radiation, and that danger is particularly terrifying because it takes a form that human senses cannot detect. When you are burned by fire or cut by a knife, you know immediately; but gamma rays could be coursing through you right now and you’d feel no different. (Huge quantities of neutrinos are coursing through you, but fear not, for they’re completely harmless.) The symptoms of severe acute radiation poisoning also take a particularly horrific form: After the initial phase of nausea wears off, you can enter a “walking ghost phase”, where your eventual death is almost certain due to your compromised immune and digestive systems, but your current condition is almost normal. This makes the prospect of death by nuclear accident a particularly vivid and horrible image.

Vividness makes ideas more available to our memory; and thus, by the availability heuristic, we automatically infer that it must be more probable than it truly is. You can think of horrific nuclear accidents like Chernobyl, and all the carnage they caused; but all those millions of people choking to death in China don’t make for a compelling TV news segment (or at least, our TV news doesn’t seem to think so). Vividness doesn’t actually seem to make things more persuasive, but it does make them more memorable.

Yet even if we allow for the possibility that death by radiation poisoning is somewhat worse than death by coal pollution (if I had to choose between the two, okay, maybe I’d go with the coal), surely it’s not ten thousand times worse? Surely it’s not worth sacrificing entire cities full of people to coal in order to prevent a handful of deaths by nuclear energy?

Another reason that has been proposed is a sense that we can control risk from other sources, but a nuclear meltdown would be totally outside our control. Perhaps that is the perception, but if you think about it, it really doesn’t make a lot of sense. If there’s a nuclear meltdown, emergency services will report it, and you can evacuate the area. Yes, the radiation moves at the speed of light; but it also dissipates as the inverse square of distance, so if you just move further away you can get a lot safer quite quickly. (Think about the brightness of a lamp in your face versus across a football field. Radiation works the same way.) The damage is also cumulative, so the radiation risk from a meltdown is only going to be serious if you stay close to the reactor for a sustained period of time. Indeed, it’s much easier to avoid nuclear radiation than it is to avoid air pollution; you can’t just stand behind a concrete wall to shield against air pollution, and moving further away isn’t possible if you don’t know where it’s coming from. Control would explain why we fear cars less than airplanes (which is also statistically absurd), but it really can’t explain why nuclear power scares people more than coal and oil.

Another important factor may be an odd sort of bipartisan consensus: While the Left hates nuclear power because it makes corporations profitable or because it’s unnatural and despoils the Earth or something, the Right hates nuclear power because it requires substantial government involvement and might displace their beloved fossil fuels. (The Right’s deep, deep love of the fossil fuel industry now borders on the pathological. Even now that they are obviously economically inefficient and environmentally disastrous, right-wing parties around the world continue to defend enormous subsidies for oil and coal companies. Corruption and regulatory capture could partly explain this, but only partly. Campaign contributions can’t explain why someone would write a book praising how wonderful fossil fuels are and angrily denouncing anyone who would dare criticize them.) So while the two sides may hate each other in general and disagree on most other issues—including of course climate change itself—they can at least agree that nuclear power is bad and must be stopped.

Where do we go from here, then? I’m not entirely sure. As I said, statistical data by itself clearly won’t be enough. We need to find out what it is that makes people so uniquely terrified of nuclear energy, and we need to find a way to assuage those fears.

And we must do this now. For every day we don’t—every day we postpone the transition to a zero-carbon energy grid—is another thousand people dead.

Should we give up on growth?

pnrj core principles, development economics, ethics, futurism, macroeconomics, public policy , , , , , , , , , , , , , , , , , , , ,

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.