09 October 2008

Eating the seed grain

Alex Steffen at World Changing frames our problem well.
One way to wrap our brains around the implications of that many people sharing a small planet is to do some math, divide up the usable part of the globe by the number of folks who want to use it. This would give us a sense of what a fair share would be for each of us.

To be really fair, though, we should probably not use up everything right away. Our kids and grandkids may want to eat, drink and breathe, too. So, we should probably only take as much as we can while allowing nature to renew itself.

It's like when people plan for retirement. You save money — build up a investment portfolio, say — and then try to live on the revenue those investments create. In this case, our natural “capital” is a gift we've inherited simply by having the good luck to evolve on such a bountiful planet. And in using that capital, we should leave enough nature undestroyed that future generations can draw upon it as well. We should leave the capital alone and live off the interest.

So, really, we don't have an entire planet to use, if we're being fair about it. We don't even have a quarter of the planet to use. What we have, if we're being fair, is that portion of the planet that we can use without trashing nature so badly that our grandkids are reduced to grubbing for withered tubers in a world of cockroaches and weeds — divided by the number of people who want to use it.

How much nature is that per person? Well, luckily, some ecogeeks have worked that out for us. They've found a way to measure the impacts of our lives on the planet, what they call our “ecological footprints.” In a fair and sustainable world, these ecological footprints would work out — in Matthis Wackernegel's equations, which really smart people seem to think are pretty accurate, if not perhaps a bit optimistic — to about 1.9 hectares per person (that's 4.7 acres). In other words, if you divided the usable part of the world up by the number of people who want to use it, we'd each have find a way to meet our needs sustainably from the bounty of a little under 2 hectares.

Unfortunately, we're already using an average 2.3 hectares per person, planetwide. To make matters worse, our sustainable share of the planet is shrinking. Part of this is a natural result of population growth: divide the planet by more people and you get a smaller piece of land.

But the planet is shrinking for another reason: we're using it up. We each get 1.9 hectares, and we're already using 2.3. Where's the extra half a hectare coming from? It's coming from nature's capital. Every year, we cut more forests, graze more cows, drive more miles, dump more trash — gobble up more stuff, and spit out more waste. And since we're already gobbling and spitting more than the planet can sustainably take, the result is that every year nature has less to offer us. To make matters worse, this spiral seems to be accelerating and the gap between sustainability and reality widening.

Here too, really geeky guys with supercomputers have gone to work, and one thing they've found is pretty shocking: as they'd put it, we're already using between 40 and 50% of the world's “net primary productivity.” What that means, for those of us whom math makes sleepy, is that humans are using about half of all the life on earth — that about half of all the plants, insects, microbes and mammals alive on the earth are being sucked into the systems that go to feed our needs.


d.a. said...

Holy crap - I just about wet my pants in fear from that last paragraph. Yikes!

Jonathan Korman said...

Aye. It's the fundamental reason why we're seeing so many species extinctions: there ain't enough capacity left over in the biosphere to support them all.

ArtSparker said...

How do you convince people to have less babies? T. Coraghessan Boyle said something in the NRDC magazine a couple of years back about ten years of sexual abstinence solving a lot of the problem...

Jonathan Korman said...

That's actually easy, artsparker. Giving women more education in general, more family planning education in particular, and more economic independence all have been shown to reduce birthrates; give women all three and birthrates go down a lot.

Now if we can just figure out how to run an industrial economy without population growth ...

Anonymous said...

Sorry, Artsparker and JK, but I get annoyed by people in a country that consumes most of the world's resources talking about population growth as though that is the major problem. The major problem is US, folks! Our country consumes far, far more of our fair share, far, far more than those "overpopulated" places.

Yes, population is too big. I get it. I'm not having children, (and our friend Germany's low birth rate is now starting to concern their govt). But over-consumption is a much greater issue. Let's educate women about that. While we're at it, let's educate the men, too.

Great article, though. Thanks for the link.

Jonathan Korman said...

Well, the US consumes roughly 25% of the world's resources, depending on how you count. As we have about 5% of the population, that's both an injustice and and opportunity — if Americans can reduce their consumption, it can make a big difference.

But it doesn't make enough difference. If Americans could live on locust and honey and stop consuming any resources, that would only bring us down to 75% of our global consumption, which ain't enough to save the world. Humans would still be using a lot of resources, and most of us are living too close to the bone to survive on any less. We really do need less people.

Western consumer culture and global overpopulation are two of our top four problems, especially given that the latter is projected to get significantly worse very quickly. (The other two are the structural commitments we've made to inefficiency like urban sprawl and bad agricultural policy, and the poor alternatives we have to carbon-emitting energy sources.) Thorn is of course right to emphasize Western consumption—but global population is indeed of equal importance ... and these two are the ones where we actually have the knowledge and ability to make things a lot better if we just have the will to do it.