In the social circles I move in there is a lot of concern with overpopulation. Now, it is somewhat ironic to me that those who are concerned do not tend to breed so as to be virtuous…while others who are not so concerned, such as Sarah Palin (and also these ladies and gentlemen) make up for the balance (and some!) and render the valiant efforts of the concerned rather moot. In any case, I had a thought today…I remember when I was a small child that world population was between 4 and 5 billion. Today is between 6 and 7 billion. That is rather staggering…that my lifetime has witnessed the birth of billions. I’m not that old.
Of course I’ve read The Population Bomb and The Population Explosion. I was interested in demographics enough so that I actually used to read The Population Bulletin. But over the years I’ve gotten less interested in the topic. First, when it comes to civilizational collapse I think our psychological constraints and the consequent problems with irrational herds are more problematic than the risk of exogenous environmental shocks (the latter may trigger the former, but I am of the opinion that the former may emerge naturally even without exogenous environmental shocks; the real estate bubble and collapse did not occur because of the shock of new land supply!). Second, birth rates are dropping.
A quick back of the envelop using data you can find on Wikipedia suggests that the world population has increased by 37% in my lifetime, with the United States itself increasing in population on the order of 25%. The low, median and high projected populations in 2050 suggest that the increase between now and then will be 11%, 27% and 39%, respectively. Even the highest projected values show slower growth than in the last quarter of the 20th century (previous UN projects have tended to overestimate in the future because of the unpredictability of fertility drops). Here’s the rate of growth over the past 50 years or so:
I assume the “correction” in the early 1960s is thanks to Chairman Mao. Now that’s making a difference!
Razib Khan’s degrees are in biochemistry and biology. He has blogged about genetics since 2002, previously worked in software development, is an Unz Foundation Junior Fellow and lives in the western US. He loves habaneros.
December 21st, 2008 at 8:25 am
Would the population growth be concentrated in groups that don’t support equal education, and tend to keep women barefoot and pregnant?
December 21st, 2008 at 12:40 pm
Would the population growth be concentrated in groups that don’t support equal education, and tend to keep women barefoot and pregnant?
the last is almost tautological
December 21st, 2008 at 4:53 pm
The growth won’t last.
Thanks to the global economic crash, the most unstable nations will probably decend into civil war and collapse, and if we are really lucky/unlucky, we get major international wars as well.
December 21st, 2008 at 5:34 pm
People worry about the ethics of putting corn into gas tanks with ethanol when populations are hungry.
Compressed natural gas in cars, and replacing coal for electrical production, are worse. Natural gas is what fertilizer is made out of. Increasing demand and consumption of it will cause the price of fertilizer to go up, and accelerate the inevitable.
December 21st, 2008 at 10:32 pm
So when Haber and Bosch, back in WWI, used their process to make ammonia without using a smidgen of natural gas, they must have been cheating.
December 21st, 2008 at 10:51 pm
Most fertilizer is made from natural gas. If the demand for, and price of, natural gas goes up, food gets more expensive. That makes things worse for populations on the edge. Then we fight over resources even more than we do today.
If you look at world population vs. oil output, there is an almost linear relationship. For every 4.5 bbl/yr of additional capacity, one more person has been added to the earth’s population.
December 22nd, 2008 at 12:53 am
Would the population growth be concentrated in groups that don’t support equal education…
The best cross-national predictor of low fertility is the level of female education.
December 23rd, 2008 at 10:47 am
In the social circles I move in there is a lot of concern with overpopulation.
Hooray for Oregon! I’m glad to know such social circles exist.
I’ve eschewed breeding for both environmental and personal reasons. Based on observations of myself and others, I conclude that the personal reasons trump the environmental. People who just don’t want kids – the “childfree” – won’t have ‘em, whether they’re environmentalists or not. People who do want kids will have them, regardless of larger concerns.
Breeding simply isn’t rational. If an environmentalist wants to breed, they will. Sometimes they go through absurd mental contortions to rationalize it, which is embarrassing: witness Bill McKibben’s intellectual train wreck Maybe One. But rationalizing either way isn’t necessary. You want kids, or you don’t. Reasons why are a mystery, like sexual orientation.
That said, many people ignore their hearts in these matters and simply do what is expected of them, which historically is to (heterosexually) marry and have kids. Often people who really don’t want kids have them anyway, due to social pressures. So it’s worthwhile to remind people that not having kids can be more altruistic and unselfish than having them, since many unthinkingly believe the opposite. Hence this cartoon.
December 23rd, 2008 at 11:19 pm
Nina P, have you read the antinatalism blog?
December 24th, 2008 at 5:53 pm
Great, just great…All the people ahead of the bell curve don’t want kids, whereas those behind are mating like bunnies. If you truly care for the environment, make some babies that are capable of dealing with the problem! The real issue isn’t overpopulation-its whether or not future generations will be equipped to deal with it.
December 26th, 2008 at 2:53 pm
I agree with Dionysus. People should have as many or as few children as they want, be that number 8 or 0. But I see no reason to not have children because of the environment. Past predictions of doom resulting from overpopulation have never come to pass. Either intelligent people stepped up to the plate and came up with technologies to increase the world’s carrying capacity, or the world’s carrying capacity has always been more than people supposed. Either way, I notice that it’s only intelligent types who wrestle with the idea of whether to breed. We have more to fear from a coming idiocracy than we do from overpopulation.
December 28th, 2008 at 8:01 pm
Paul Collinvoux, in “Fates of Nations” suggests that people tend to have as many children as they can afford. Well-off people find children to be very expensive to raise, and thus can only afford a few. Poor people find children much less expensive to raise, and possibly an economic plus, so they tend to have more. This strikes me a bit simplistic, but having some truth to it. This sugggests that as human population grows, the proportion of poor in the total population will increase. Seems to be the case. One of the most effective things to do is to change the status of women so that first births are at a later age. This was shown years ago (by Sokol?)that this is mathamatically much more effective than attempting to limit total number of children. It is said, in illustrating that war is not effective in limiting population, that the population of Viet Nam doubled over the course of the Viet Nam war. Maybe so.
December 30th, 2008 at 5:01 pm
Mark, Yes, as we all know from the story of the boy who cried wolf the wolf never came.
December 31st, 2008 at 1:53 am
There’s also the question of personal preference, isn’t there?
1) I don’t like an ethic of “let’s pack as many in as we can! Just because we can!” I just don’t. Don’t like it where food is concerned, where housing is concerned, where cars are concerned … Well, maybe where “transistors on a chip” is concerned I’m ok with it. Otherwise, I find it bullying and inelegant. Blech to it.
2) I’m old enough that the population of the U.S. has doubled in my lifetime, from 150 mill to over 300 mill. I liked the place better (at least so far as pop. density went) when it had fewer people than I do now that it’s twice as crowded.
*Can* we pack more people in than we have already? Probably, what do I know? But is it desirable? That’s a question that isn’t asked often enough, IMHO.