You see, I thought there would be a very simple answer. I was sure that a scientist had done some calculations that would figure out the exact carrying capacity of Earth. By "space" I was assuming that we'd be talking mostly about food. Food takes space to grow and it seems like simple math. The problem is that there are lot of variables that go into it. First, the better we get at growing food, the more people we can have. We're getting better all the time. Plus, the more people that start growing food in their yards, roofs and indoors, the more people Earth will support. But none of this takes into account the natural environment.
I'm a biologist, and the one thing I find most dear are wild places. If you stop and think about it, do we include the land in our national parks as free game for growing more food? I would say we wouldn't but in theory, it is space!
The next time you go for a drive think about all the places we could theoretically grow stuff. Everyone has yard space. Shopping centers have space. Roofs to buildings have space. The woods in neighborhoods could be chopped down and planted with food crops. Every body of water could have aquaculture. The list goes on and on. But is that what we want?
Do we really want to get better and better at using our space, just so that we can have more people on Earth? I pondered that very question last month when a friend turned their yard into a garden. Obviously a lot of hippie types advocate that we should all do that. The more I think about it though, the less I think it's something we need to promote everyone to do. I mean, it would make sense if we were then going to convert the existing cropland into forests and the human population had stopped growing. The better we get at maximizing space, the more free space we open up for population growth. Does this sound ridiculous and somewhat selfish? Probably.
The way I see it, I want to save biodiversity. I'd like nothing more than to buy up lots of land and protect it. I'll have my little house, and burn my firewood from trees that fall on the property. People might complain that I'm not using energy efficiently, but it's all carbon neutral, so I won't feel too bad. The native critters will come and go and hopefully I can create one big island in the ever growing concrete landscape. That can't be so bad, right?
To wrap this up, I'd simply like to say that I hope we don't ever really hit a number where we as a human species run out of space. I hope that we can find a way to stop growing, simply because we want to maintain a healthy lifestyle, not because we're hungry and can't grow more. That is my hope, and I'm not sure exactly what we have to do to get there. Oh well, I suppose I don't need to obsess about it too much. I've already got my little house and a bit of land. Let's see how long I can keep it that way.