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Comment by pfdietz

7 hours ago

Back when LtG came out, there was a study of the limits imposed by resource availability. The conclusion was that, to first approximation, the only resource that we had to worry about was energy. Fossil fuels would have to go, but everything else was either available in effectively unlimited amounts or could be substituted with things that were. An example of the latter was mercury -- effectively all previous uses have been replaced with better substitutes (because of toxicity issues, not shortage of the element.)

Pollution also has to be worried about, but there's nothing in a non-fossil fuel powered world that would prevent the current world population from enjoying prosperity indefinitely. There are ultimate limits to energy use on Earth from direct thermal pollution but the world could enjoy US levels of wealth without great trouble.

The exponential process one should be most concerned about today is exponential decline in population.

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pfdietz

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projektfu  6 hours ago

When is the world population expected to decline? Or are you talking about a specific country?

  • pfdietz  6 hours ago

    I'm talking about the entire world.

    Almost everywhere, the total fertility rate is well below replacement (which is around 2.1). UN estimates that say global population will peak around 2084; they assume global TFR increases back to 1.6, but there is no evidence for this assumption, so global population will likely peak sooner. Every first world country will be in population decline by 2050; some already are.

    There's something about global civilization that's acting like a kind of human pesticide. People just aren't having kids, and this is getting worse, not better.

    • projektfu  1 hour ago

      So it seems there is a median projection of mild decline way in the future. There are also reasonably probable scenarios that show no decline, or more precipitous decline. However, they generally agree that there will be at least 1 billion more people in the world, most likely 2 billion, and possibly more.

      What is the real risk of the Earth eventually going back toward having 8 billion people after reaching 10 billion? Why is this "the exponential process one should be most concerned about today"?