159 Comments
Jan 6Liked by Noah Smith

This was such a relief to see a sane and balanced discussion of the issues. I hadn't realised the extent to which fertility declines were already occurring in China and India before the major Government interventions. But as you say, habitat destruction and loss of biodiversity are still pressing problems that have not disappeared just because we haven't had mass human starvation. I also wonder whether the social and political consequences of where rapid population growth is still occurring can be accommodated in a world where migration is such a contentious issue. As Brad DeLong shows there's plenty to go round but we're not a very sharing species.

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Jan 6·edited Jan 6Liked by Noah Smith

Even if we never got more productive at farming, one thing that was never clear to me is why Erlich predicted a population combustion and mass famine, versus a situation where population asymptotically leveled off at the level of agricultural productivity. Moreover, the price mechanism and other economic forces would probably lead to a smoother and potentially higher asymptote than a situation where nothing changed but population level. For instance, increases in the relative price of arable land and food could make it such that before people would starved outright, market forces would push rural folks into denser settlements, making more room for food growth.. Meat would become relatively more expensive to grow, and shifts to cereals would increase calorie yield per hectare . Other accommodations too numerous to think of would probably occur and lead to a smoother and maybe much higher asymptote, even in the absence of the revolution in crop yields per hectare.

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Degrowthers are just one element of an approach to the environment which treats the environment as a moral (see below) rather than practical issue. And they pose a massive political barrier to actually getting something done about the environment.

I mean why is the right so anti-enviornmental? It's because they've learned over long decades that most environmental messages they hear can't be trusted as they try to slip in value propositions they disagree with.

I myself used to be a relative skeptic of global warming simply because so much stuff I'd seen about environmentalism was ultimately crap driven by feelings about wastefulness or growth. I had the ability to actually understand the science and figure out what was serious scientific concern and what were value judgements posing as concern.

Until there is a backlash from those of us who care about the environment (because we want to keep it around for ppl to enjoy and avoid flooding cities) against the constant stream of anti-growth ideas masquerading as environmentalism (just a few weeks ago the NYT was running a story about the environmental harm of throwing away cheap furniture despite the fact that there is scarcity of places we could put garbage) I fear it's going to be very hard to get a large chunk of the western world onboard with things like a serious carbon tax.

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Of course practical concerns have moral impact but here I mean moral in something like the Haidt purity foundation sense. For them it's not about weighing costs and benefits but about reducing our wasteful western lifestyle that they in some sense see as an afront to the natural order.

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Jan 6·edited Jan 6Liked by Noah Smith

“ Biodiversity loss has financial impacts: The cost of recent losses of ecosystem services has been estimated at USD 4 trillion–USD 20 trillion per year. Land degradation is estimated to cost USD 6 trillion–USD 11 trillion per year, and oceanic degradation USD 200 billion per year.6, 7, 8”

This seems high but if it is true, even within an order of magnitude, it would behoove economists to take these numbers seriously in GDP calculations. If the US is losing midwestern soil at these values, at what point does the bank run out and real economic damage is done to the economy? Ten years? Twenty? Do we have $100,000,000,000,000 worth of soil to run through?

See https://am.jpmorgan.com/us/en/asset-management/adv/insights/portfolio-insights/sustainable-investing/the-economic-importance-of-biodiversity/

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Jan 6Liked by Noah Smith

Agreed with this, although I will say it was a bit of a close call with Borlaug and the Green Revolution. One of the things that came across in Charles Mann's account of Borlaug's efforts is the role of contingency in its timing, and we got very lucky there - a decade's delay in its implementation was not implausible, and would have been very bad for world hunger.

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Jan 6Liked by Noah Smith

"This depiction of animals as savage beings who care only about killing and sex is strongly at odds with the experience of anyone who has actually been around animals and seen them demonstrate love, playfulness, and kindness."

This may be the first time I've seen your love of bunnies influence your writing. I approve.

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When you walk on the University of Minnesota campus, it has statues ready for the discovery as most campuses do. One of them is of an alumni named Norman Borlaug, an agronomist. While there are many metrics by which lists are made, Mr. Borlaug eventually won a Nobel Prize for his decades of efforts to bring the green revolution to the world. It can be reasonably argued that he led an effort that saved 1B lives. By that measure, one of the greatest people who ever lived and almost no one knows who he is. For the baseball aficionado he is key in the effort to bringing baseball to Mexico where the game has flourished. I wrote about him early in my Substack journey but bad forn to include links. Continue to love your writing.

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Jan 6Liked by Noah Smith

So happy to see you put the emphasis on non-human animals and habitat loss in this post Noah. The non-human world is one of the great lacunas in our collective consciousness. Notice how the recent COP meeting on biodiversity in Montreal only garnered a fraction of the attention of the climate COPs for example. Relatedly, a lot of folks have been led to believe that it is climate change that has inflicted much of the present damage on the natural world when in fact habitat destruction, inefficient agriculture, harvesting and invasive species have done most of it by far.

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What is missing from the discussion is luck. Charles Mann in his book "The Wizard and the Prophet" lays out a compelling case that the success of the dwarf-stem wheat hybrid that Norman Borlaug created was by no measure a sure thing due to the unique genetics of wheat. While many point to the Green Revolution as proof of mankind's ingenuity and capacity to adapt to circumstances, my own view is that the world was very lucky that Borlaug achieved his breakthrough when he did. Exclusively due to his own perseverance, he was able to provide high-yield seed to Pakistan and India in 1968, the same year as The Population Bomb was published. Many of those who are eager to critique Ehrlich are too cavalier in my opinion to history. Hence I tend to be quite more pessimistic that high population growth areas in the world such as Nigeria, Sub-Saharan Africa, and the poor parts of the Middle East will be able to avoid the perils that Ehrlich warned about.

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Jan 6Liked by Noah Smith

You can 'degrow' the economy and still ruin the planet

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Jan 6Liked by Noah Smith

When I heard predictions about the future in the 60s and 70s--which did not come true--I realized that that those linear measurements did not reconcile the nature of human knowledge and achievement. Scientific advances, knowledge, and experience have effects which are exponential, not linear. In other words, those (incomplete) predictions are based on a linear timeline assuming that the knowledge of the past will march along in a straight line. Loved your article!

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"one good rule of thumb is probably to be suspicious of people who package their warnings with pre-prepared solutions." Watch out - Noah is a declared techno-optimist. Which error does tecno-optimists make? Presume that technology's historic capability to provide solutions to historic problems implies the capablity of future technology to provide solutions to (different) future problems. No better than Ehrlich.

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This reminds me of Y2K. We discussed the impending Y2K disaster in software development already in the 1980s. By 1998, the industry had begun investing heavily in Y2K mitigation. Development teams throughout the industry were identifying and correcting Y2K problems. By 1999, the investment must have been in the billions.

When 1 Jan 2000 rolled around, I, along with many other engineers, was on 24hr call. I got no calls. Y2K was a big meh. I, and thousands of others, breathed a long sigh of relief as hundreds of thousands of fixes averted a disaster. The rest of the world laughed at the apparently needless panic over a non-event. What a waste of concern, they said. But the insiders knew that the world had dodged a devastating bullet.

The Y2K phenomenon is relevant to Ehrlich. He inspired remedial thinking, not as direct, perhaps, as Y2K, but folks began to look at global development in a new way. His crystal ball was wrong, but he inspired a way of thinking that will save us.

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“This depiction of animals as savage beings who care only about killing and sex is strongly at odds with the experience of anyone who has actually been around animals and seen them demonstrate love, playfulness, and kindness.”

Hmm. My doggie is loving and playful. His favourite play is MURDERING his squeaky toy, and he’s also never happier than when killing rats. I’m not sure bunnies (❤️❤️❤️) are the right sample to generalize from to the whole animal population.

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Jan 6·edited Jan 6

Again, a gloss of “progress” with no mention of the downsides. The Green Revolution of a souped-up wheat variety requires previously unheard-of amounts of fertilizer and water. The petrochemical/corporate farming industry is more than happy to continue greater consumption of hydrocarbons and desertification of vast tracts of soil via irrigation. The chemical runoffs poison our biggest river systems, creating an ever-growing dead zone in the Gulf of Mexico, to say nothing of the salts precipitating into soil horizons from irrigation of semi-arid areas that shouldn’t be farmed. Once you kill off enough bacteria in the soil via osmosis, desertification begins. There is a reason Darwin spent the last 20 years of his life studying earthworms and formation of soil. If scientists acknowledged how long it takes for one inch of new soil to be created and the current rate of lost soil/agricultural land, they couldn’t justify their creation of agrochemicals, pesticides, etc. and their participation in corporate farming. We’re repeating the centuries-old trend of eroding civilizations -- the difference being that with the “advancement” of science we should know better. Mono-cropping agricultural land, killing off pollinating insects (arthropods largest biomass on the planet) via insecticides, exhausting fresh-water acquirers to accelerate desertification (75% of pivot irrigation water is lost to evaporation on a hot summer day), is a recipe for disaster. With all-time record heatwaves, droughts and high winds, the amount of annual soil lost is accelerating. Why is all this excluded from analysis of future trends? More people than ever before are forced to migrate because of climate change, and this will only worsen unless we start to question corporate farming and supposed “scientific advances.” Sure, the “Population Bomb” was wrong, but only because it measured the wrong things.

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Jan 6Liked by Noah Smith

Great article and much needed perspective. Brings to mind the predictions of Thomas Malthus in his 1798 work An Essay on the Principle of Population.

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