Tuesday, January 29, 2008

Limits to Overhead

As I’ve mentioned, my population-consumption model predicts that on a per capita basis the world must add at least one new energy resource for every resource we consume to keep the world’s population (technically, the amount of people using energy) from decreasing. Our ability to survive this situation depends on how much of what we consume that we can devote to finding new resources, what business people might refer to as “overhead.”

In that vein, an economic perspective can be gained from my equivalent model of the Gross World Product (GWP), which shows that we must currently add 80 cents worth of productivity for every dollar an average person produces; this happens to be close to the average of the required per capita ecological and energy resource additions as a fraction of consumption. Put another way, we must each (on average) acquire 80 cents worth of resources for every dollar we spend. How much of that dollar we use to acquire those 80 cents is the “overhead” that allows us to use the remainder without causing people to die.

Of course, the longer we wait, the more resources we will need to add. My GWP model suggests that if we wait until 2020 to start adding resources (as well as keeping the population from growing and keeping per capita consumption constant), the 80 cents per dollar climbs to 88 cents. If we wait until 2079, we will each have to add more than the total we spend (replacing more than our entire economic output). The time we will each need to add more ecological resources than we consume is much earlier: 2036, which is much more problematic since the associated population peak is only two years later.

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