Populations

Several years ago, in “Half-Life,” I projected that the populations of other species, measured by the Living Planet Index (LPI), would reach the half-way point by this year (relative to its value in 1970). That isn't going to happen, mainly because humanity would need to be consuming 1.9 times the ecological production of the planet (“Earths”), and we are only consuming about 1.6.

This expectation is based on the notion, common in sustainability literature, that the sum of the ecological resources consumed by all species (including ours) is a constant. Further, it assumes that the consumption by other species are related to the size of its population as my current population-consumption model describes for humans. As I discussed in “Approaching the Peak,” our consumption appears to be climbing to a maximum of 2.0 Earths, which corresponds to an LPI of 0.46. I now project that if we manage to consume a little more than 3.1 Earths in a given year (a number very close to the constant pi), the LPI will be at zero, which is a euphemistic way of saying that we will have effectively killed the planet, and almost certainly ourselves. Note that this is another one of those strange rules of thumb: Consume up to one Earth to live sustainably; consume two Earths as a natural target (which may still coincide with consuming Nature's producers that we most depend on, and result in our population crashing), and consume three Earths to wipe out everything.

The U.N. recently reported its own projections for population and consumption in 2050. I was able to reproduce its numbers by performing curve fits on population and the consumption that I had derived in my recent modeling (see “Discontinuity”). As I did, they may have used three possible scenarios for population and consumption to derive their expected values. In my case, one of the scenarios is a “worst case” curve-fit, showing our population peaking in 2028 and dropping to zero by 2073; as our consumption falls, other species will have more to work with and their populations will rise after bottoming out at an LPI of 0.57. Another scenario is my population-consumption model's gradual leveling off as consumption stabilizes. The last scenario is a best-case curve fit, with our population and consumption rising rapidly, at the expense of other species, who die off by 2029. Combining these three scenarios using a PERT estimate is what yielded the U.N. estimates, which, if it meets the definition of “expected case,” will finish off other species by 2041, and likely us too.

"Green" Economy?

According to the U.S. Department of Labor, “The green economy encompasses the economic activity related to reducing the use of fossil fuels, decreasing pollution and greenhouse gas emissions, increasing the efficiency of energy usage, recycling materials, and developing and adopting renewable sources of energy.” This presumably reflects the thinking about “green” jobs in the real economy of the United States, which prioritizes the continued energy and material flow through our civilization and the availability of those parts of “the environment” that people directly use.

The use of the term “green” triggers imagery consistent with a natural setting dominated by plants, and by extension, more biodiversity. Rightly, many of us tend to associate this with a better life. Unfortunately, because the green economy as presently defined only peripherally addresses a few of the causes of our biosphere's degradation, and is likely to exacerbate others, the result is not likely to match our expectations from the imagery.

Biodiversity loss is perhaps the largest single manifestation of biosphere degradation. Habitat loss, population growth, and invasive species (three of the five largest causes) may actually increase as a result of green activities, and the continued reliance of green technologies on electronic technology may not alleviate the pollution problem (the fourth cause) outside of a very narrow range of harmful substances. Habitat loss is a consequence of our appropriation of land and other resources from use by wildlife, which is likely to increase as we mine more materials for new technologies, build more buildings, erect large-scale wind and solar installations (along with their distribution and transportation infrastructure), and devote land to the growth of biofuels. More efficient resource use tends to drive up consumption because people feel free to use more (viewing the savings as the equivalent of new resources); and as per-capita consumption increases, so does population (enabling full use of the available resources). Wherever people go, other species go with them, among them our favorite monoculture crops, often displacing the natives and sabotaging ecosystems. Now, with biotechnology and species bred for biofuel use, we can introduce a range of new species that may wreak even more havoc.

If we were to more broadly define the goals of a green economy to include a healthy biosphere where people use only what can be replenished without harm to each other and other species, we might truly have a healthier world as a result. It is almost certain to be very different from what we currently have, so different perhaps that a job classification system like the one used by our government wouldn't even be meaningful.