How Many People Can the Earth Support? Some Thoughts

How Many People Can the Earth Support? Some Thoughts October 30, 2011

Rather than a tightly argued piece with a particular conclusion, I want to just share some ideas (and links and videos) that have come into my head given the recent media flurry about the fact that, as of Oct. 31, 2011, there are going to be more than 7 billion of us.

Much hullabaloo has been made about this number, but it seems to me that virtually no one actually knows what on earth they are talking about.  Much of the commentary I have read seems blissfully unaware that population growth is actually slowing dramatically and that virtually all demographers expect human population growth to be negative by the end of this century.  Most are trucking along with an idea they heard in middle-school, helpfully illustrated by scary looking wall-charts, namely, that human population is expanding exponentially and will keep doubling until certain cataclysm.

Here’s a graphic refutation of those numbers:

(Now there’s a lot of refuting of the Population Research Institute out there, but I haven’t seen any refutation of this.  Feel free to share if you have seen such a refutation.)

If you’ve read the news stories and blogs, and especially the comments, you know that the ignorance people are willing to showcase on the issue is simply staggering.  Many will throw out some random number that they have no way to substantiate:  “The earth can support 3 billion people.  We’re already 4 billion over the limit!”  I mean, what on earth does such a claim even mean?  Others say things like, “We need a world war or an epidemic to save us from certain disaster!”  But world wars and epidemics are disasters.  What exactly are they saving us from?  Future wars and epidemics?  Of course dead people don’t do a lot of dying, but what of it?  One of the creepier things is the blatant racism in many of the comments I’ve read.  Concern about minorities breeding and coming to steal our land and resources makes me queasy.  And, in Canada, we’re begging them to come over in order to support our retirement funds.

One of the more balanced pieces I read noted that, as the earth’s population nearly quadrupled over the last century, it’s food production “miraculously” kept pace.  But why “miraculously”?  There were four times as many workers to grow the food, weren’t there?  And it’s not like we’re close to running out of arable land.  I mean, take a walk down the street and try to estimate how many potatoes could be grown on the lawns of you and your neighbors, should necessity demand it.  As urban gardening projects are starting to show, cities themselves have room to produce a serious percentage of their own food, especially poorly designed sprawling cities.  And the amount of resources we put into growing grass that nobody eats is overwhelming.  Heck, we grow grass on farms and ship it into the cities!

One of the more interesting things I’ve encountered in this schmozzle is an argument that the earth could easily support 100 billion people:

Now, while some Catholics will be happy to make such arguments their own, I would offer a caution against salvation by technology.  Benedict XVI himself has warned against this temptation.  And conservative Catholics who want to argue for the earth’s capacity to hold vastly more people than it currently does need to be careful about endorsing something that would necessarily require massive social engineering.

Now, I have no idea how many people the earth can support.  As Joel Cohen, who actually wrote a book on it, notes, the only reasonable answer is, “It depends.”  The problem is so complex, with so many variables (think only about the vast discrepancy in resource consumption between one person and the next), that no one can actually give any serious answer to it.  Cohen’s measured and thoughtful approach here is one of the more helpful things I’ve encountered:

In any case, these basic claims seem true:

1.  No matter how many people have lived on the earth in the past, a good number of them have been close to starving.  Getting rid of people isn’t going to get rid of this problem.  We live in an age where we can easily produce enough food for all, with such a surplus that there is enough to help when disaster strikes a particular locale.  We need to focus on building a system that distributes food justly and efficiently.

2.  Certain lifestyle choices and economic systems are destroying our environment and that destruction increases when such lifestyle choices are made by more and more people.  It makes no real difference whether that means people born into the most wasteful cultures, people who immigrate to them or people who are importing wastefulness into their own cultures.

It strikes me that population growth is not, in itself, a problem.  On the other hand it serves to highlight these two other problems (at least).  It may be that a lower percentage of us is near-starving than in much of human history, but the total numbers (900 million) still demand something be done, especially given our incredible productive capacity.  It is obscene to throw away so much food while others starve.

And something must be done about our whole throw-away lifestyle.  Our per capita waste keeps going up even as we recycle more.  My Mom was a teacher for 30 years.  When she began, the garbage pail at the end of lunch time has a few apple cores and banana peels.  Today it is overflowing with plastic.  Even recycling all that plastic, if it doesn’t go to the landfill, takes resources.  Consumerism simply produces too much junk.  And my Mom’s classroom is only a tiny microcosm of a world that throws away whole mountains and rivers.

There are some of my rather disjointed thoughts.  What are yours?  In particular, have you seen any credible claims about how many people the earth can support?

You might also find these other pieces of mine interesting:

Demography and the Future of Religion:  Eric Kaufmann’s Shall the Religious Inherit the Earth

Preliminary Ramblings on Population and the Environment

Brett Salkeld is a doctoral student in theology at Regis College in Toronto. He is a father of three (so far) and husband of one.

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