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I don't think this shift has anything to do with people wanting to reduce the birth rate, though I agree that this situation is something we were going to have

I don't think this shift has anything to do with people wanting to reduce the birth rate, though I agree that this situation is something we were going to have to deal with eventually. We live in a world with finite resources. I've seen a few scientists point out that you can never continue exponential growth in a finite system. Whether it is the population or the economy, we have to level-off at some point. Sadly, the ecological limit is imposed by starvation. I'd like to think we're smart enough to stop before that.

Dove 17y ago
World population growth is not exponential, but logistic. A logistic curve looks exponential until you pass the inflection point. IIRC, we did that in the '80s.
- lotharbot 17y ago
  Yes[1]; most of the current population estimates show the world population leveling off in the 9-12 billion range. Percentage growth rate actually peaked in the mid 1960s (about 2.2%), and absolute growth peaked in the late 1980s (about 85 million people per year.) This is completely expected from logistic growth models[2]. Different species reach logistic growth in different ways. As the grandparent post noted, "reduced birth rate" is better than alternatives like "mass starvation". Lower birth rates are not a bad thing from a population growth perspective, though the demographic shift they bring about will require changes to our expectations regarding retirement. It's rather unfortunate that we're still using a retirement model designed when life expectancy was lower and birth rates were higher. [1]"Who's that insightful person who posted about logistic growth and stole my thunder? Oh, hi, honey!" [2]The image at http://www.growth-dynamics.com/articles/Kurzweil_files/image004.gif http://www.growth-dynamics.com/articles/Kurzweil_files/image... shows actual world population data following a logistic curve, compared to an exponential curve above.
dgordon 17y ago
Fortunately, another limit is imposed by women getting access to education and then birth control. That has played a huge part in bringing the birth rate down.
BearOfNH 17y ago
We live in a world with finite resources 150 years ago, i.e., back when I was born, we were worried about that finite resource called whale oil. It was indispensable for lighting lamps. But somehow we managed to find an alternate. So yes, if you think in terms of say petroleum then we're facing some unpleasant limits. But there are many alternatives including renewable resources that aren't so finite. Silver, rhodium and a number of rare earths are more problematic.

Dove 17y ago

World population growth is not exponential, but logistic. A logistic curve looks exponential until you pass the inflection point. IIRC, we did that in the '80s.

lotharbot 17y ago
Yes[1]; most of the current population estimates show the world population leveling off in the 9-12 billion range. Percentage growth rate actually peaked in the mid 1960s (about 2.2%), and absolute growth peaked in the late 1980s (about 85 million people per year.) This is completely expected from logistic growth models[2]. Different species reach logistic growth in different ways. As the grandparent post noted, "reduced birth rate" is better than alternatives like "mass starvation". Lower birth rates are not a bad thing from a population growth perspective, though the demographic shift they bring about will require changes to our expectations regarding retirement. It's rather unfortunate that we're still using a retirement model designed when life expectancy was lower and birth rates were higher. [1]"Who's that insightful person who posted about logistic growth and stole my thunder? Oh, hi, honey!" [2]The image at http://www.growth-dynamics.com/articles/Kurzweil_files/image004.gif http://www.growth-dynamics.com/articles/Kurzweil_files/image... shows actual world population data following a logistic curve, compared to an exponential curve above.

dgordon 17y ago

Fortunately, another limit is imposed by women getting access to education and then birth control. That has played a huge part in bringing the birth rate down.

BearOfNH 17y ago

We live in a world with finite resources 150 years ago, i.e., back when I was born, we were worried about that finite resource called whale oil. It was indispensable for lighting lamps. But somehow we managed to find an alternate. So yes, if you think in terms of say petroleum then we're facing some unpleasant limits. But there are many alternatives including renewable resources that aren't so finite. Silver, rhodium and a number of rare earths are more problematic.