United State's "Carrying Capacity" reached in the late '70s ?

DUers, awhile back in a calculus text re growth and decay rates I came across the estimate that the US had reached its environmental carrying capacity of about 200 million sometime in the '70s. The only eqivocation with this conclusion came from factoring in the deaths from wars, mostly the Civil War, into the mix.

What IS the US's carrying capacity, now that we're about to hit 300 million ?

http://dieoff.org/page110.htm

Because carrying capacity varies with resource availability.

The US population has effectively increased it's "foraging" range since the 70's through increased imports.

If you take away the energy subsidies that make agriculture and imports possible and availability of resources to the population markedly changes.

Thomas Malthus came up with the whole concept that humans were doomed to reach the limits of their resources and would begin to die back. Some historians used to talk about "Malthusian Cycles" to explain the rises and falls of population and even civilizations.

Malthus's writings seemed to predict the fall of civilization in the 19th century, and advocated abstinence and late marriage as a way to voluntarily delay the ultimate demise of mankind (There's debate whether Malthus was actually making a prediction or was just demonstrating what could happen). Advances in technology, agriculture, economics, government, etc, allowed population to survive a bit longer.

Still seems to be surviving. Doesn't mean it won't die one day, but so far we keep making advances that outpace our population. Better transport, refrigeration, computer models, etc.

Every religion has its Doomsday, including science (which has several). They are healthy, in that they warn of the possibilities of wrecklessness, like the Ant and the Grasshopper story. But they are lousy, so far, at predicting the actual end of all as we know it.

Religion has nothing to do with it, by 2031 China and India-- emulating the US's economic system, which requires what, 5 earths now ?-- will force the issue.

Plan B 2.0 book on web
http://www.earth-policy.org/Books/PB2/Contents.htm

Please read the segment "Learning From China".

One of those books comes out every year or so, and has since humans began writing. Before that, they told the same story around the campfire. So far they've been as right as the various other predictions of the end of the world.

I think clearly the major issue facing humans is answering the question how many people should populate the Earth? I think clearly we CAN survive with 300 million people in the US, but that doesn't mean we should. In terms of population density the US is actually in better shape than many nations.

We're in better shape.