[jeffreymcmanus]

I've seen people react at this figure in horror, as if there is some fixed limit to the number of humans that earth could possibly support. But earth's resource problems are really problems of distribution, not scarcity. And at least one of those 7 billion will figure out how to enable the earth to support 8 billion and more.

[jbooth]

I dunno if I'd definitively say it's purely distribution. Surely even with perfect distribution there's a point where scarcity becomes a factor, even assuming technological progress, unless you're talking unlimited energy and star trek replicators.

[artmageddon]

I'm more curious / concerned about how we'll be able to manage all the resources needed to support another billion without stripping the earth to the point that we find ourselves in a collapse because we've run out of water / food / oil / etc.

Of course, the same thing was said when the global population hit 1 billion, and so forth... thus I do agree that given we're an innovative species there is a good chance we'll survive.

[0x12]

Whatever the limit is, there is a limit. Because there is a limit to the earth. Whether that limit of sustainability is 2 or 50 billion is something we haven't figured out yet but that there is a limit seems to be something you can't around.

[ars]

Why is the limit on earth?

[0x12]

Because it just so happens that this is where we are.

Earth can only sustain so many people, and since we do not currently have a viable way to get off this earth and/or to terraform other planets (hell, we can't even agree on a common plug to use for household appliances) it looks like it will remain that way for a while.

[ars]

Yah, but it will also take a while to reach the limit of the earth, by that point we will hopefully be able to expand off of the earth.

[jeffreymcmanus]

Um, we've left the earth already. The only reason why we don't continue to do so is that it isn't cost-effective -- which means that we have another resource-allocation problem rather than some mysterious insurmountable challenge.