Bullets that we’ve dodged as a species

The Rational Optimist: How Prosperity Evolves gives an inspiring list of predicted catastrophes that have failed to occur. I’m going to limit the list to ones that have been predicted during my lifetime (born 1963).

Cancer. Rachel Carson predicted a big increase in cancer due to due to DDT, which would cause “practically 100 per cent of the human population to be wiped out from a cancer epidemic in one generation.” Paul Ehrlich, a MacArthur genius, also predicted doom from DDT: “The U.S. life expectancy will drop to forty-two years by 1980, due to cancer epidemics.”

(another) Nuclear War. It once seem inevitable that we would have a species-ending nuclear war with the Soviet Union.

Famine. Environmentalist Lester Brown predicted imminent famine in 1974, 1981, 1984, 1989, 1994, and 2007, in a 1967 book titled Famine, 1975!, and by MacArthur genius Paul Ehrlich in a 1968 book The Population Bomb (repeated, but without a predicted date, in a 2008 book, The Dominant Animal).

Exhaustion of minerals, oil, etc. We did indeed use up all of the known reserves of zinc, gold, tin, copper, oil and natural gas by 1992, just as predicted in the Club of Rome’s 1970s bestseller Limits to Growth. But then we found some more.

Air Pollution. Flying a small plane into the Lower 48 from Alaska or the Caribbean, I’m often amazed at how brown the air looks hanging over Washington State or Florida. On the other hand, it was supposed to be much worse. “In 1970, Life magazine promised its readers that scientists had ‘solid, experimental and theoretical evidence’ that ‘within a decade, urban dwellers will have to wear gas masks to survive air polluion… by 1985 air pollution will have reduced the amount of sunlight reaching earth by one half.'”

Plague (AIDS). “The number of deaths from [AIDS] has been falling since 2005.”

Plague (Flu). Ridley claims that the 1918 flu epidemic was unique due to the environment of soldiers in trenches. A successful modern flu needs its victims to be well enough to walk around, go to work, and spread the disease further.

Global cooling. If not for all of the dinosaur blood that we’ve pumped out of the ground and set on fire, we would in fact be going (slowly) into another ice age. This frightened journalists and their readers in the 1970s and a lot of ink was spent on dire warnings about climate change similar to today’s articles, except that the promised temperature trend was opposite.

Ridley suggests that we count our blessings. The last few years have seemed to offer a lot of lessons about human hubris. Here are some of the things that we’ve learned we can’t do safely: (a) drill for oil in mile-deep water (Deepwater Horizon), (b) build nuclear power plants on tsunami-prone coastlines (Fukushima), (c) build the world’s biggest airliner and engines (Qantas Flight 32), (d) protect cities that are below sea level from flooding (Katrina in New Orleans). On the other hand, none of this seems to stop the human population from expanding and, overall, from enjoying a better standard of living than previous generations.

[June 8 update: NYT carries a Thomas Friedman column “The Earth is Full” saying more or less the exact opposite of what Ridley wrote. They both have great credentials (Ridley has a doctorate in science; Friedman was smart enough to marry a billionaire heiress) so it is tough to know whom to believe.]

33 thoughts on “Bullets that we’ve dodged as a species

  1. On Global cooling – equating this (largely a media frenzy spurred on by scifi writers with no actual science in the peer-reviewed journals of note to back it up) to today’s science (peer-reviewed journals about as unanimous as they ever get) which is largely dismissed by the media (or put on an even keel with denialist tripe) – you have gone off the Tea Party deep end. Very disappointed.

  2. M1EK: Ridley does not deny that the earth has been getting warmer or that it will continue to get warmer. He merely states that the consequences probably won’t be as bad as our current worst fears. I don’t have enough background in meteorology and geology to form my own opinion on the subject.

    [I’m not sure where you found the Sarah Palin bumper sticker on the above posting. Is there a law that whenever one mentions “climate” one must also reference the latest batch of journal articles on the subject? The subject of the posting was old predictions that didn’t pan out as bad as feared, not evaluating the quality of current predictions.]

  3. Some of these did not so much fail to occur by themselves as were averted,
    eg: Clean Air Act made a huge impact on air quality since 1970
    http://www.arb.ca.gov/html/brochure/history.htm and http://www.edf.org/documents/2695_cleanairact.htm
    When I’ve gone to industrial areas/cities in most other countries with no such controls I truly wished for a gas mask. Combatting these trends required some loud and sometime obnoxious activism which may have included less than rational pessimist fringes. That includes environmental movement as well as the fight against AIDs – without awareness-raising/legitimizing efforts of early activism AIDS might not have been such an optimistic story today. The danger with reading such accounts to optimistically is in dismissing as shrill some of our current concerns without doing much about it.

  4. The Katrina failure is a big one, but I think maybe it’s that the US can’t protect a city below sea level. The Netherlands has a better track record.

  5. LT: I think Ridley is budgeting in human action and adaptability of the kind that you describe. Part of his point is that a prediction based on humans not changing their behavior is likely to be wrong. For example, Americans would not respond to a 10X increase in gasoline prices by continuing to drive 7,000 lb. SUVs on multiple trips per day.

    Supposedly people in almost every country around the world have started to demand a cleaner environment as soon as their average income reached $4,000 per person. So the Clean Air Act is not an anomalous freak event due to some particular personalities in the Nixon Administration of 1970. It is similar to what humans in every industrializing society have done.

    Regarding AIDS, I’m not sure how “activism” in the U.S. had an effect on the disease failing to spread among Africans as predicted. Presumably the main factor was people changing their behavior after seeing first-hand the consequences of their traditional behavior. Once again, Ridley would say that this is a well-established element of the human personality and that predictions that fail to take it into account are likely to be wrong.

    Joe: True on the Netherlands.. so far. And the Dutch do a lot of other things better than we do, e.g., honest financing of pensions (see http://philip.greenspun.com/blog/2011/04/19/the-economist-magazine-pension-issue/ ).http://news.bbc.co.uk/2/hi/science/nature/8362147.stm says they have engineered for a 10,000-year storm. I’m not sure that the U.S. couldn’t do it, but perhaps it doesn’t make financial sense for us? The Dutch have nowhere else to live. The U.S. has a lot of open land that is well above sea level. Imagine what it would cost to have government contractors and the U.S. military build something like what the Dutch have. It would probably be cheaper to build an entirely new city (think “Dubai”) a bit inland and abandon those portions of New Orleans that are most vulnerable.

    [For reference, most of the sources I found online said that the Dutch have spent $8 billion on their defenses, which include 3500 km of dikes. The U.S. military spent $6.9 billion on http://en.wikipedia.org/wiki/Comanche_helicopter , of which two were built before the project was scrapped. A few years later the government wasted $3.3 billion on a new presidential helicopter (for 5-10 minute flights from the White House to Andrews Air Force Base, for example) before shutting the program down (and all that they were trying to do was adapt a European helicopter that first flew in 1987).]

  6. I see Phil tripped over the PC line when it comes to commenting on global warming. Or is it “global climate change”?

    Personally I think burning dinosaur blood is, at best, a minor secondary factor in the Earth’s climate. And I can cite quite a bit of peer reviewed research to that point. But I don’t want to be accused of helping Sarah Palin.

    As to the things we can’t do safely…

    a – I don’t know. How many mile deep wells operate year after year with no issue?

    b – We couldn’t do this in the 1960’s and 1970’s. A passively safe reactor design, which is possible today, would have just sat there after the tsunami waiting to dry out and be put to use again.

    c – no comment.

    d – agreed 100%.

    I would also add e: elect politicians who won’t bankrupt a nation state through ever increasing deficits, borrowing, and spending. It would appear to me that’s the most perplexing and dangerous issue facing the west today.

    Looks like The Rational Optimist will find its way onto my iPad tonight. It will be a nice change from all the gloom and doom we are exposed to daily.

  7. (More in response to LT) I don’t think any of the dangers quoted were ever originally seen optimistically, but it’s fortunate enough to see them now as such because it’s fairly pleasant to realize we’re not actually as dumb as we believe and actually fix the problems we find.

    Most of the predictions, made by people who are probably quite knowledgeable otherwise, seem to either be incredibly narrow (“Too much DDT, we’ll totally never make another, better pesticide/realize we’re wrong and DDT isn’t as dangerous as thought”) or don’t seem to take into account that we won’t actually twiddle our thumbs and do nothing (AIDS prediction, for instance). And even if a natural resources prediction came to pass, who’s to say we wouldn’t have found equal/better replacements. If we can’t make deep water drilling effective, perhaps we can find another, potentially better, extraction method.

    Also, on global cooling, as far as I remember, a lot of the earliest papers in the mid-70s about global warming warned that it would become a problem precisely because it will completely reverse and overtake the effects of the known cooling issue. Also see ban on CFCs.

  8. It’s funny, Philip, I usually think of you as extremely negative (but in an entertaining way). You’ve recounted innumerable stories about how stupid and irrational people are. You’re becoming an optimist now?

    Consider the unforeseen horrors of the 20th century. The economist and economic historian Brad DeLong writes that the saddest book he can think of–“a marker of a better future that did not come to be”–is Norman Angell’s “The Great Illusion” (1910), which explained why war was a thing of the past. It was published just a few years before the mass slaughter of the First World War began.

    Four decades later, in 1951, Hannah Arendt wrote:

    Two World Wars in one generation, separated by an uninterrupted chain of local wars and revolutions, followed by no peace treaty for the vanquished and no respite for the victor, have ended in the anticipation of a third World War between the two remaining world powers. This moment of anticipation is like the calm that settles after all hopes have died.

    Will the future be better than the recent past? Maybe. Maybe not.

  9. Does Ridley go into the politics of DDT? My understanding is that people like Rachel Carson issued warnings, research backed her up and then laws were passed to ban the use of DDT. If that is correct, the predictions of doom from Carson and Ehrlich must have saved some lives, no?

  10. Vince: Ridley does talk some more about DDT. He cites a U.S. National Academy of Sciences report estimating that DDT saved roughly 500 million lives (from malaria and typhus) in the 1950s and 1960s. He indicates that it is a good thing for wildlife that we’ve replaced DDT with “less persistent chemicals” for large-scale use (e.g., on farms) but implies that we should use DDT more within households.

  11. > The Katrina failure is a big one, but I think maybe it’s that the US can’t protect a city below sea level. The Netherlands has a better track record.

    How many category 4 or 5 hurricanes has Holland experienced?

  12. Loosely related: Assuming that climate change will happen and will cost a lot of money to “handle”, how is largely ignoring it and handing the bill to future generations different from doing the same thing with government expenses? What I’m saying is that just because we can expect to be able to tackle something when it gets really serious it’s rarely the better solution.

  13. Because we were just discussing our Texas gun laws here at work, I can add another prediction of doom that didn’t come to pass.

    Until recent times Texas had an almost total prohibition on the transportation of firearms by private citizens. In 1994 Governor Bush signed a concealed carry law allowing Texans who took a safety course and passed a background check to carry concealed weapons. Subsequent changes established the right of all adults to carry firearms from place to place in their cars.

    Lots of well meaning people predicted that blood would run in the streets. Austin would become Doge City. Every fender bender would result in a shoot out. All those criminals deterred from carrying firearms by the law would feel free to begin pillaging the countryside.

    Of course none of this happened. Crime rates went down, especially home invasions. Numerous crimes were stopped in progress by CHL holders, mostly without the CHL holder actually firing his or her weapon.

    And it turned out that CHL holders are about the most law abiding demographic out there.

    Amazingly, criminals didn’t flock to their local police stations to be photographed, fingerprinted, and background checked!

    I recall that liberal writer Molly Ivins was particularly hysterical on this issue, but she did come up with what I thought was an excellent suggestion for Texas License Plates. Instead of saying ‘Drive Friendly’ as they did back then, she wanted them changed to say ‘Drive Friendly – Or Die!’. Which was fine by me.

  14. Joe: allowing future generations to deal with climate change makes sense because they will have much better technology and will be much richer than us. Would it have made sense for people in the nineteenth century to make sacrifices to solve the increasing problem of horse manure piling up in the streets, say by limiting the number of horse-drawn carriages that could be sold? I’m sure some doom-monger predicted that by the mid-twentieth century the streets of London would be waist-deep in horseshit. Fortunately no-one listened to him.

  15. Owen: It does seem odd that Ridley was “non-executive chairman” (board-level position, not operational) of a big bank (Northern Rock). Why was he hired? He doesn’t seem to have had any qualifications other than that his dad was chairman before him (see http://en.wikipedia.org/wiki/Matt_Ridley ). Naively one would think that it would be good to have worked at a bank before becoming chairman of a bank.

  16. Stephen: the counter-argument is that it’s far more expensive to recover from a disaster than it is to prevent it. Imagine that you drop a giant jar of water: it’s going to be really, really hard to put together the shattered pieces, no matter how rich you are. (The Himalayan glaciers, which act like giant water towers for Asia, are melting much faster than expected.)

  17. Russil: Suppose that we need to substitute energy generated by photovoltaic cells for energy generated by burning coal.


    says that the cost per watt has fallen from $27/watt in 1980 to $2/watt in 2009.


    says that wind power in 2004 cost 1/5th as much as it did in the 1980s. http://www.cato.org/pubs/pas/pa-280.html provides some similar numbers for wind power.

    Even if we assign a discount rate of 0% to future expenses, it still wouldn’t make financial sense to try to solve all of the world’s future problems today. As Stephen points out, people of the future will have superior technology to what we enjoy today.

  18. Philip: I suppose. I think of the greenhouse gas problem as a tragedy of the commons, i.e. a political problem, not a technical problem. And political problems are much more intractable than technical ones.

    25 or 50 years from now, when our children or grandchildren are struggling with the greenhouse effect, they’ll face the same political challenge: how do you control access to a valuable resource, namely the atmosphere, that anyone can use for free? Why should any individual country cut its emissions voluntarily?

    The outcome has been that we’ve dumped CO2 into the atmosphere at a rate far beyond what’s sustainable. The last time atmospheric CO2 was this high was 15 million years ago:

    I think Ridley and Friedman are both wrong. Friedman is an optimist as well: his conclusion is that we’re too smart to walk off a cliff. I’m dubious. Barbara Tuchman’s “The March of Folly” describes several such examples.

    Speaking of follies and disasters, I suppose Northern Rock itself provides an obvious example of people blundering into disaster through stupidity. Ridley is refusing to take questions about Northern Rock.

    Parliamentary report on Northern Rock: http://www.publications.parliament.uk/pa/cm200708/cmselect/cmtreasy/56/5602.htm

  19. Russil: Saying “CO2 levels were the same 15 million years ago as today” would not necessarily convince someone such as Ridley that disasters were imminent and immediate action was required. An optimist could point out that the earth is still here and still habitable and that the high CO2 level of 15 million years ago did not lead to a runaway greenhouse effect and turn earth into venus. An optimist would also point out that the earth becoming “different” from the past does not mean that it will be “worse”.

    [As noted earlier, I’m not an expert in this field so I don’t offer my own opinion on global warming, etc. My back-of-the-envelope hypothesis is that it is probably a bad idea to dig up all of the world’s coal and oil and set it on fire, but I don’t know enough science to work out all of the effects. Ridley, in any case, disagrees with me. He says it is a good idea to dig up fossil fuels and burn them because otherwise we’d have to use up a lot more of the land for growing fuel for immediate use.]

  20. “probably a bad idea to dig up all of the world’s coal and oil and set it on fire”


    If you’re looking for a good source of information on global warming, I’d suggest skepticalscience.com.

    “An optimist could point out that the earth is still here and still habitable and that the high CO2 level of 15 million years ago did not lead to a runaway greenhouse effect and turn earth into venus.”

    True. On the other hand, sea levels 75 feet higher than they are today might be a bit inconvenient. There’s also even more extreme scenarios:

    If you run into an optimist like this, I’d suggest quoting this deadpan response (from “Lab Lemming”):

    From a geologic point of view, carbon dioxide is irrelevant to climate. This is because the CO2 will simply accelerate silicate weathering, drawing it out of the atmosphere and eventually precipitating it as carbonate.

    While there may be transient effects, the timescale of those effects is too fine to resolve geologically, so they aren’t worth worrying about.

    As for the effects of climate on the biota, that too is irrelevant. Species go extinct all the time, and when they do, something else radiates into their niche.

    So from the planetary perspective, this whole CO2 thing is just another blip like the PETM. In a few million years, it will be nothing but a curiosity. Narrow-minded activists interested in the survival of particular subgroups such as ice-dwelling pinnipeds or bipedal primates might complain, but to what end? We’re all headed for the fossil record eventually, so changing the extinction time of a particular group by a few tens of kiloyears isn’t going to be detectable in the long run.

  21. Russil: Sea levels 75 feet higher than today would definitely exacerbate Florida’s real estate slump and it sounds like a good premise for a Hollywood disaster movie. On the other hand, the consensus over at Wikipedia (http://en.wikipedia.org/wiki/Current_sea_level_rise ) seems to be that sea level has been rising between 1mm and 3.4mm per year. As 75 feet is 22,860 mm, it would take between 6,723 years and 22,860 years for sea levels to rise 75 feet, assuming that they continued rising at the current rate. The worst case estimate cited in the Wikipedia article is that sea levels could rise by at most about 6 feet by the year 2100. If things continued at that worst-case rate, we’d reach your scary 75′ number twelve centuries from now.

    Would it have made sense for peasants in the year 800 AD to have spent their scarce resources on solving problems that they expected their descendants to experience in the year 2000?

    Or is there an important scientific prediction about future sea levels that the Wikipedia authors did not find and that has us going to the beach in West Virginia within our lifetimes?

  22. Procrastination is a winning strategy in the face of impending doom, because it lets you gather more information before you make a decision. For example, in the few years that we delayed acting to avert the threat of global warming, we learned that the Himalayan glaciers are not actually receding(http://wattsupwiththat.com/2010/01/20/ipcc-admits-error-on-himalayan-glacier-melt-fiasco/).

    Fear that the world is about to destroyed is a psychological phenomenon common to people in all times and places. It’s nothing to be ashamed of. We may as well stay on our toes.

  23. Without going into the specifics of Ridley’s arguments and the matter of climate change, there’s a lot of propositions that people are conflating (presented in abstract to minimize emotional reasoning):

    1. Phenomenon X is happening, with forecast magnitude M

    2. Phenomenon X with magnitude M is a bad thing

    3. Activities Y are causing phenomenon X to get to magnitude M

    4. Policies or actions Z mitigate or control the effect of activities Y on phenomenon X, stopping it from achieving magnitude M

    5. Cost of actions Z is better than the cost of phenomenon X at magnitude M (and this includes the opportunity cost of the actions that Z will preclude in the forecast period)

    6. Structures put in place for actions Z will only be used for actions Z and not abused or hijacked for purposes different than that of avoiding phenomenon X at magnitude M

    7. All this can be accurately predicted at the present time and there’s some enforceable commitment on the part of all actors, regardless of change in the prediction of M, the badness of X, the obsolescence of Y, the incentives for Z, and whatever else the future may bring.

    Even if one believes in 1-3 (or even 1-5) that doesn’t necessarily imply all the other propositions.

  24. “Or is there an important scientific prediction about future sea levels that the Wikipedia authors did not find and that has us going to the beach in West Virginia within our lifetimes?”

    No, no, no. I’m just referring to the UCLA press release, which describes what the world looked like 15 million years ago, the last time CO2 levels were this high: “…global temperatures were 5 to 10 degrees Fahrenheit higher than they are today, the sea level was approximately 75 to 120 feet higher than today, there was no permanent sea ice cap in the Arctic and very little ice on Antarctica and Greenland.” The UCLA press release certainly isn’t predicting that this is going to happen in our lifetimes.

    What scientists are predicting is that pretty soon, CO2 levels will reach high enough levels to melt the Greenland ice sheet. (The Greenland ice sheet contains enough ice to raise sea levels by 7 metres.)

    [At 400 ppm] the ice-sheet loses ice mass in the north of the island, with a total reduction in ice volume ranging between 20 to 41%. Note – due to the large inertia of the Greenland ice sheet, this mass loss doesn’t happen at the moment CO2 levels reach 400 ppm but over a period of centuries. Under a 560 ppm climate, the Greenland ice sheet loses between 52 to 87% of its ice volume. If CO2 reaches 1120 ppm, there is almost complete elimination of the Greenland ice sheet with loss between 85 to 92%. The important result from this paper is that there is a critical threshold where the Greenland ice sheet becomes unstable somewhere between 400 and 560 ppm.

    This is a large uncertainty range and one imagines there will be much research in the next few years to reduce the uncertainty. However, the 400 to 560 ppm range is put into perspective when you look at the projected CO2 levels for the various IPCC scenarios. The business as usual scenario has CO2 levels reaching 1000 ppm by 2100.

    For current and imminent effects of global warming, see http://en.wikipedia.org/wiki/Effects_of_global_warming. To take a single local example, the mountain pine beetle (no longer killed by cold winters) has done $30 billion of damage to the British Columbia forest industry.

    We can already see that global warming is having massive effects, and doing a lot of damage (just ask the insurance industry). The problem is figuring out what to do about it.

    “Would it have made sense for peasants in the year 800 AD to have spent their scarce resources on solving problems that they expected their descendants to experience in the year 2000?”

    This may sound completely crazy – but unfortunately, that’s exactly the kind of problem we’re facing. It takes something like 500-1000 years for atmospheric CO2 to be transferred to the deep ocean! No matter which generation finally decides to start tackling the problem, they’re going to have to live with whatever the atmospheric CO2 level is for the following millenium. The later the generation, the higher the CO2 level will be, and the more intense the effects.

    The most promising approach I’ve seen so far is William Nordhaus’s proposal for the major industrialized countries to each adopt a carbon tax (thus putting a price on CO2 emissions), starting low and rising over time. It’s basically a sales tax, so it’s easy to set up and administer. Unlike a quota system, you don’t have endless wrangling over everyone’s quota sizes; you just need everyone to have their tax at the same level (and you can use tariffs to enforce this). BC introduced a tax like this a couple years ago. It’s revenue-neutral (BC is reducing its income taxes by a corresponding amount), so the economic impact is minimized.

    What’s the likelihood we’re going to be able to reach this kind of agreement at some point in the future? I don’t know. If the apocalyptic scenarios the scientists are forecasting turn out to be correct, I think the alternative to a negotiated agreement is going to be war (“politics by other means”). Given the sheer destructiveness of modern warfare, that’s a nightmare scenario.

  25. I know it’s hard to imagine that this kind of change could really be happening. Bill Hicks talks about watching CNN and it’s non-stop “famine, plague and madness”, and then looking out his front door and hearing crickets. But it is happening. Here’s a visualization of increasing CO2 levels, as measured by NASA’s Aqua spacecraft:

  26. Phil: I should have mentioned that one disadvantage of delaying action to gather more information is that there is always more information. A more recent study than the Guardian article you cited claims that many Himalayan glaciers are actually advancing, and in any case, they are geographically diverse, affected by a variety of causes, and should not be lumped together in a single group following a single trend.


  27. Matt, if atmospheric CO2 levels are now up to the same level as 15 million years ago, and continuing to rise far beyond that, what do you think is going to happen to the Himalayan glaciers?

    Note that we don’t have any way to lower CO2 levels; we can only slow down the rate of increase (and we haven’t even started on that yet).

    There’s a correction on the Telegraph article that Watts links to:

    This report has been amended since it was first posted. The original headline and first paragraph may have left the mistaken impression that Himalayan glaciers in general are advancing rather than shrinking. We wish to confirm, as was made clear further on in the original article, that this finding related to only one of the areas studied, the Karakoram range, where it was found that rocks and mud on the surface of glaciers are helping to protect them from melting.

    The UCSB press release that Watts links to states:

    Bookhagen noted that glaciers in the Karakoram region of Northwestern Himalaya are mostly stagnating. However, glaciers in the Western, Central, and Eastern Himalaya are retreating, with the highest retreat rates –– approximately 8 meters per year –– in the Western Himalayan Mountains. The authors found that half of the studied glaciers in the Karakoram region are stable or advancing, whereas about two-thirds are in retreat elsewhere throughout High Asia.

    SkepticalScience: are glaciers growing or retreating?

    What about the long term trend in global glacier mass change? There are several method to calculating global glacier mass change. One way is to use the average value of the 30 reference glaciers. Another is to calculate the moving average of all available glaciers….

    Both approaches show consistent results (with all glaciers showing a slightly faster drop in mass compared to the 30 reference glaciers). There is strong mass loss in the first decade from 1945. Note that at this time, there were only several glaciers monitored – not quite a global sample. The mass loss slows down in the second decade so that around 1970, global mass balance was close to zero. Glaciers were in near equilbrium which indicates glacier shrinkage in the late 20th Century is essentially a response to post-1970 global warming (Greene 2005).

    After 1975, glacier shrinkage continues to accelerate until present. The mass loss from 1996 to 2005 is more than double the mass loss rate in the previous decade of 1986 to 1995 and over four times the mass loss rate over 1976 to 1985.

  28. I seem to recall that Jared Diamond had a few cases where things didn’t turn out so well in his “Collapse” book.

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