I have known about the concept of carrying capacity for a long time, but have been thinking about it more lately, as world news brings more and more evidence of humans bumping up against our planet's physical limits. It also is in the back of my mind as I consider what this 40 acres ( 16 hectares) might ( or should) look like in 20 years.
Carrying capacity is another of those fractal things, where it can be viewed from the planetary level, right on down to plant spacing in a garden row.
Carrying capacity is also complex in that it's not just the human centric view of how many humans can be supported ( though that's usually what is implied) , but should really focus on long term overall health of the entire biota. And local ecosystems are not static either, evolving and going through cycles on different and sometimes random durations.
In looking at our farm, and food production in general, it can be tricky to draw an appropriate system boundary and fully account all the inputs and outputs crossing that boundary. Thought needs to be given on what a reasonable area is for calculating carrying capacity.
A watershed? A region? A homestead? I happen to live in the Kickapoo River drainage basin, or watershed. No question at all that I still import large amounts of fossil fuel enabled external inputs in our little farm, but I hope year by year to reduce that.
The reality is, humans have been transporting resources and materials across distances for millennia, though of course for the last century give or take, we are a couple orders of magnitude beyond what can be done with muscle power or water or wind.
It is pretty obvious that carrying capacity of a specific area is lower if no material movements or cross subsidies are done, and some balance will be struck at a much lower rate of production as we end the fossil fuel era.
And human activity can affect the "base" carrying capacity absent external inputs as well. Trees can be cut down, soil eroded, square miles paved over in urban areas, with regrowth or healing taking from decades to centuries. In the other direction, trees can be planted, water retention structures built, or complex and resilient plant communities can be nurtured.
Overall the planetary carrying capacity has been degraded by human actions quite a bit. A couple years ago, I posted about humans as a keystone species that lost our way. The rogue keystone species
I guess I'm still dwelling on it, and still hoping we can renew our role as a positive contributor and an intelligent collaborator with our fellow organisms.
Humans are ( hopefully, maybe?) a special case, in that we are able to anticipate, or imagine possible futures, and then steering our actions in the present to make them so. Human scale agriculture, permaculture, animal husbandry, and similar technologies give us the chance to increase our species' individual carrying capacity, but with wisdom, we could be improving the carrying capacity of a region for all its inhabitants.
Og and Trog were creeping up on the megatherium, and each slowly nocked an arrow to prepare their attack. Only two men attacking a huge ground sloth was borderline doable, but they couldn't pass this up. As they drew back and began aiming, Og's bowstring went "twang!" and broke.
"Well crap" he said. "I didn't bring a spare, have you got one?"
Trog said, "Sure; here, string it up before this beast gets away."
Og took it and unrolled it, and began to string it, but then he looked at it for a bit, puzzled. He then took one of his arrows, and tried to see if the string would fit in the arrow nock, which it did not, it was too thick.
He looked at Trog, and hissed "What the hell is this?"
Og had been staring intently at the megatherium, but turned and looked at Og, who was almost hopping foot to foot, so anxious was he that the tribe's next week of meals was slowly shambling away, and he had no functional weapon.
Og whispered back " Do you mean you are still using the OLD strings? Bog has been making the new stronger ones for four moons now. I can't believe this!"
Trog was purpling around the temples now, and said "Nobody told me about this crap, and you know I've missed the last three hunts with that leg the wooly rhino stepped on!" He sputtered "And besides, the old strings worked just fine."
"Well", Og said, "We don't dare try to take down this beast with only one weapon, I guess we are screwed."
Being paleo-Indians, they didn't talk much. This had been a remarkably extended conversation, brought on by extreme duress. They silently trudged back home, knowing that by the time they rearmed, the big lug would be long gone.
And so Og and Trog's tribe did not make it through the winter that year. Oh, there was still some game around, but it was getting more scarce every year, what with more and more mouths to feed, and another tribe taking up residence just two valleys over, and all the smaller game seemed to be quicker and more wary than the big lumbering ones they had relied on for many generations.
14,000 years later:
Steve remembered that he had tucked away the Home Power magazine collection on CD when they had moved, but had't looked at them for ages. When he had finally decided to move to a Mac instead of a PC, that had been one of the main reasons he made a point of purchasing the accessory external CD drive, since the Mac had no disc drive. He was thinking this might be the year to do solar thermal water heating, and wanted to go back and pull up the best articles for review.
He fed the first CD into the drive. It hissed and clicked, the software finally launched, and the table of contents came up on the screen.
The first article he clicked on did not come up however. Instead, a message said that Apple no longer supported power PC. "But these are PDFs, why does that matter?" he thought. Steve, not being a computer whizz, had no idea why the Mac was not backward compatible with what he thought was a universal format.
He played around with different ways of trying to get at the files, but to no avail. How odd, the table of contents come up, but not the individual files. This was over his head.
He then used bad language, a bad habit which showed no signs of going away.
Yes folks, all those terabytes of research, heartfelt blog droppings, cat videos, and political memes that our species cranks out continually will be as mist over a pond come the morning sun. Slowly fading and gone forever. Oh, some of it might still exist in some sense, but after twenty upgrades and four format revolutions, it will be as useless as a Clovis point would be to try to start your car with.
