Letters to the Editor

• Biomass

  [Read the article: "The World Without Us"]
  [Read more letters about this article: Here]

  Sounds like a great book to add to the shelf with Jared Diamond, next to Dawkins' "Ancestor's Tale", "Rare Earth", any number of essays by Asimov, whole swaths of SF - and plenty of standard textbooks on economics and population dynamics. Google "Malthus" and "tragedy of the commons". Our problem isn't that our best and brightest don't understand the issues. Our problem is the smug inaction of imagined personal gain. It is the pure mathematics of compound interest that will kill us:

  "The power of population is so superior to the power of the earth to produce subsistence for man, that premature death must in some shape or other visit the human race. The vices of mankind are active and able ministers of depopulation. They are the precursors in the great army of destruction, and often finish the dreadful work themselves. But should they fail in this war of extermination, sickly seasons, epidemics, pestilence, and plague advance in terrific array, and sweep off their thousands and tens of thousands. Should success be still incomplete, gigantic inevitable famine stalks in the rear, and with one mighty blow levels the population with the food of the world." - Malthus

  The current population scorecard stands at 6.602 billion souls growing at a rate of 1.167% annually. Plug the numbers into any mortgage calculator on the web - that's 60 years until the next doubling. This seems optimistic since the last doubling took 40 years, but stretching the doubling timescale a few decades makes no difference to the outcome.

  The Earth's biomass scorecard stands at 1900 gigatonnes of carbon. Human flesh is about 18% carbon. Plug the numbers in (I assumed an average human weight of 30 kg, e.g., 67 lbs) and we find that the mass of human flesh will equal the mass of all life on Earth in just 960 years.

  The mass of the Earth itself is 6x10^24 kg. Plug the numbers in - The mass of human flesh will equal the mass of the Earth in 2700 years. This Yertle scenario may seem a little unlikely due to the unknown behavior of co-gravitating human bodies, so how about limiting our horizon to the crust of the Earth, about a half a percent of its total mass. Pop - just 38 doublings of the current population taking us to AD 4287. A few millennia more, however, and the mass of human flesh equals the mass of the entire universe - so much for a space-based solution.

  The point isn't that we will reach these absurd limits - the point is precisely that we can be sure that we won't. The implication is that something most definitely will change in the next millennium - and it won't be the mathematics. Slowing down compound interest is a vain hope - even a 0.1% growth rate will lead to "peak human" scenarios no less dire within a few centuries.

  We also can't base our hopes on a change in human nature. We won't evolve that quickly. Education can help - but only in the sense of an educated community influencing lawmakers and lawbreakers (e.g., corporations and the current administration).

  What will happen is one of only two things: a catastrophic collapse of civilization - perhaps not such a bad thing given the book being discussed. Or - a reconfiguration of our local and global governance to be responsive to the shared real world outside our species, not just the diverse fantasy worlds within.

  Permalink Monday, July 23, 2007 02:37 PM

• it IS about ZPG

  [Read the article: "The World Without Us"]
  [Read more letters about this article: Here]

  Without a functioning throttle on Malthusian growth, our species' population will soar and crash over and over. Meanwhile, each cycle of collapse will exhaust more - and more types - of resources, starting with petroleum. Each successive industrial civilization will have less available to reboot the system. Even if we avoid a global catastrophe of the nuclear winter or hey-where-did-the-gulf-stream-go variety, our progeny will ultimately live a stunted and persistently brutish existence approximating the complete absence speculated upon in this book. The only two ways to achieve a zero population baseline is to minimize births or maximize deaths. Presumably we would prefer the former.

  Alternatively, I suppose, one could play the game by positing that our absence has been caused by the biblical rapture. Surely, however, the natural market for this book rests within the reality based community.

  All that ails humanity scales with, or faster than, population.

  Permalink Monday, July 23, 2007 07:24 PM