by VMarcHart » Fri 22 May 2009, 09:39:31
$this->bbcode_second_pass_quote('jdmartin', 'T')hat [carrying capacity] definition is always changing, both locally and globally. It's impossible to say with any certainty, though most of us suspect as much, that the planet's future carrying capacity for humans won't increase or decrease. If you told scientists 200 years ago that we'd be sustaining 7 billion humans on the planet, they probably would have laughed and said it was impossible. Just as we today say that 10 or 11 billion is impossible ... we'd probably easily support another couple of billion just as we are.
One American probably equals three or four Africans...we could subtract 25% of our food intake, provide it to someone else, and they'd be great.
JD, it sounds you're a bit confused with the definitions and terms.
The definition doesn't change. The carrying capacity does, due to weather, technology, etc. Thus, the planet's future carrying capacity will change; it's always changing.
200 years ago, people knew they had exceeded the then carrying capacity, they knew they were using the phantom carrying capacity, and they knew they had more people than they could feed, clothe, etc. (By people, I mean the same proportion of people that know that today; people like you and me.) Then some key inventions, such as the steam machine, increased the carrying capacity. Yes, they would've laughed at me, but the extra 6 billion since aren't being “sustained” or “supported” as you say. We are rather simply living. No different than the extra 2-4-6 extra billion people that will be added to the current population. The planet’s reserves are huge, and can allow for billions to live off it, but that doesn’t change the definition of carrying capacity.
BTW, on a footprint scale, one American equals 5-6 Africans, and on an energy basis, as many as 40.