capacity also applies to us.
TaaL: Those “upper limits” are also subject to change as a species changes. The environment’s carrying capacity for humans living as hunter - gatherers in the Pleistocene, eating mammoths, was far lower than the carrying capacity for humans engaged in agriculture, because humans learned to co- opt a greater portion of the land’s primary productivity for your own species and were additionally eating, primarily, on a lower trophic level: there will always be more biomass capacity for plant-eaters than carnivores. (Individually, your agriculturist ancestors lived much harder lives and died younger, but there were more of ‘em compared to their hunter gatherer ancestors). One thing early man discovered was that it is possible to enhance (or degrade) an environment’s carrying capacity. Irrigating with salty water messes up your fields after a few years and stuff won’t grow there anymore. If you burn down a forest to catch game, you may wind up with a grassland which supports different game. If you allow your topsoil to be washed away, you can no longer grow crops and must pull up stakes and move somewhere else. One other thing your ancestors discovered, rather more recently, was the ability to expand beyond the “agriculture” niche to the “proxy detritivore” niche, which drastically increases the agricultural carrying capacity of land by using soil as an inert medium with which to convert fossil carbon compounds into food. Most notably, your widespread use of chemical fertilizers to grow livestock feed has more than quadrupled the terrestrial vertebrate biomass of Earth in the last 150 years by decoupling it from solar flows. This increased vertebrate biomass exists as humans, cows, pigs, sheep, chickens, dogs, and other animals you favor. This redesigned human ecosystem currently has a ginormous (but fluid) carrying capacity. Other terrestrial vertebrates (known as “wild” animals) now have a drastically limited carrying capacity, for the same reasons. You no longer think you “need” topsoil, or crop diversity, or soil organisms, or bug- eating birds because they aren’t really needed when tons of inorganic fertilizer, herbicides, and pesticides dumped on each acre will pro duce higher yields. You’ve named this the “green revolution” and thereby reproduced yourself into the high-single-digit billions of individuals, shooting for double digits within decades. That being the case, there’s another ecological term you might wish to ponder: overshoot . The dynamics of carrying capacity include situations in which a species expands past the environment’s sustainable limit and over - consumes the environment, resulting in a compensatory population crash
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