[flgb]

The earth doesn't have a "carrying capacity" or a "maximum population". The earth has resources that are used more or less sustainably at different times and in different places. If we all still lived like hunter gatherers we would have run out of resources and become extinct thousands of years ago. Luckily we've had social, economic, and technological development.

As soon as anyone frames sustainability challenges in terms of the earths "carrying capacity" they are revealing a bias that is unhelpful. Even if you accept the premise that the earth does have some 'maximum population' then so what? It's a useless proposition -- what are you going to do, force everyone to only have one child, that is unsustainable as China discovered.

Luckily, as the parent pointed out, overpopulation is not a problem. The rate of growth continues to decrease, and global populations will peak in my lifetime.

[Bill_Dimm]

About 20 years ago, when I was a grad student, I attended a colloquium where the speaker (a physicist, for better or worse) had computed the number of people that the planet could support if everyone consumed natural resources at the rate that Americans do. His number was 2 billion. I don't remember who the speaker was and I don't know what assumptions he made -- I don't know how much error there might be in his result or how improvements in technology might change it. If his number is even close to being right, "global populations will peak in my lifetime" isn't even close to being adequate unless you expect the bulk of the population to be satisfied with remaining poor while a small proportion of the population devours the planet.

[Idontagree]

Which is a calculation based on current technological standards, which is also not proof that we will not become more efficient and better able to manipulate our resources as needed.

[Panoramix]

Ah, the good old "future generations will solve it, so let's trash this place"

[throwaway_789]

Strawman. Strong environmental protections and positive population growth can coexist.

And, of course, we should be striving in our generation to solve these existential challenges, rather than squandering our time optimizing sales funnels and click-through-rates.

[tremon]

"Ecologists define carrying capacity as the maximal population size of a given species that an area can support without reducing its ability to support the same species in the future" http://www.dieoff.org/page112.htm

In the interest of (scientific) discourse, it is generally unhelpful to redefine or ignore generic definitions. Are you asserting that the earth doesn't support any species, or that is perfectly possible to have googolplex people living on earth without reducing earth's ability to support googolplex people in the future?

[hguant]

I think the post is saying that defining the carrying capacity of a technological species is an exercise in futility. Malthus was writing about this many years ago - humans have a habit of raising the bar.

In answer to your googolplex question - I think it's safer to bet on the technology developing to support such a population than against it. (Though I think we'll either be extinct or an interstellar species before then.)

[tremon]

I (think I) understood the GP post, I just have very little tolerance for idiotic and easily falsifiable statements. Therefore, I chose to respond to the first sentence only, and ignore the rest of the post.

My use of that population number was simply that: a refutation of the assertion that the earth has no population limit, as it will be hard to argue that our planet can support 10^9980 humans per square millimeter of land area. A genuine "argumentum ad absurdum", to counter the GP's completely nonsensical opening statement.

[ubercore]

I interpreted the opposition to using carrying capacity to mean that it's not helpful from the perspective of a technological species. If we had that many humans, the odds seem high that we would have a way to supplement resources available to use from outside Earth. Carrying capacity is really about an _ecosystem_ and the resources it can provide vs competition with other species. We effectively have no competition, and we can create our own ecosystems, so it's kind of a strawman to apply the wildlife biology concept to our understanding of how human populations will evolve in the future.

[tremon]

Ah, but that would have been an interesting discussion. We could have discussed the merits of carrying capacity with respect to a species that builds its own ecosystem, or whether it makes sense to consider the entire planet a single ecosystem. We could have a meaningful discussion about the various population estimates and what they're based on. Or we could have discussed whether it makes sense to consider ourselves in competition with future generations.

But instead of that, the initial reply:

- refused the basic premise that would have allowed that discussion, by indirectly positing that space on earth is infinite

- followed it up with a very questionable assertion that earth's resources are used "more or less sustainably" (which is already at odds with the previous assertion that resources are infinite, and ignores the many species we've already hunted to extinction)

- added a non-sequitur that we would have run out of resources as hunter-gatherers (again at odds with the initial statement)

- justified the plain refusal of the basic premise with an ad-hominem about bias

- continued on with the apathetic rationalization that nothing can be done anyway

- concluded by reiterating the initial statement without further substantiation

Now, you may argue that my refusal to engage in that discussion is my weakness and it would still have been possible to salvage something positive, however my time is finite and there's better, less taxing discussions to be had.

(/me out, accepting that meta-justification is considered offtopic and will be downmodded).

[hellbanner]

Eventually we'll have to reach other planets.. and invent wormholes to move past the universe expanding preventing our light cones from reaching other materials.

[TeMPOraL]

Aren't we a cancer that consumes the worlds?

It gives me an idea for a sci-fi story, where a stable civilization of smart beings faces a threat of the sphere of all-consuming humans expanding at the speed of light.