I haven't written anything here in many months. In some ways not much has happened in the world, in other ways a lot. The problems of unsustainable economic and ecological systems increasingly occupy my mind. In the face of a corrupt oligarchical political system, the only way to prevent mass revolt by the starving masses is to increase total growth. As long as most people have an acceptable minimum income (whatever that level is), they seem willing to tolerate gross total inequality of distribution. "Growth" is presented as a panacea, and every piece of evidence of it is taken up by mainstream media as a positive message.

The problem is, as a biologist I see unrestrained growth as an evil. Our bodies grow when we are young, but once we reach maturity, continuing growth of any subunit of the body basically means cancer, which is ultimately fatal. The entire body can't grow indefinitely, for one thing we aren't built that way, for another we would obviously reach physical limits. For example, several hundred million years ago, the concentration of oxygen in the atmosphere was substantially greater than it is currently (it's now about 21%). One consequence was that insects could be larger. As a group, insects lack a dedicated circulatory system, so the only way the interiours of their bodies can get oxygen is by diffusion (ok there are systems of air ducts in at least some insects, but not an active circulatory network). If their bodies get too large, the cells in the center can't get enough oxygen to support their energy needs, which limits potential growth. If the overall oxygen pressure of the air is higher, then enough oxygen can diffuse to support larger bodies. There are fossils of things like dragonflies with wing spans of feet versus inches. In the case of humans, we have all kinds of physical limits that are not usually considered by economists. We can't live in air of 10% oxygen, I'm not sure where the lower limit is but it must be somewhere between 10 and the current 21% I imagine. We can't tolerate extreme heat and humidity, if we can't sweat then we die of internal overheating. We need a regular daily dose of pure water or salt concentrations and pH become unbalanced which is fatal (probably to our brains first).

Economists tend to assume human technologies can overcome all such physical limits. Indeed this may be the case at least enough to support some people, but not all. Technological solutions have to work not just for a few, but for all 7+ billion of us, else we end up with dystopias as described by many science fiction writers and movies.

The point is that economic growth requires energy consumption. For now that mostly means fossil fuels, with the result of increasing greenhouse gases. If we keep this up too long, we'll end up like Venus (atmosphere mostly carbon dioxide and water, super high pressure and temperature that of molten lead). I imagine a handful of elite could survive this underground, but imagine bunkers for 7 billion - not likely.

Even if we manage to wean ourselves from fossil fuels, energy consumption still means heat, as there is no beating the second law of thermodynamics (when it comes to energy, you can't win, and you can't even tie). If the heat can't escape the earth, then temperature rises. Things like melting the permafrost and releasing trapped methane, could cause a Venus-like future even if we were fully "green" in terms of energy production.

No one can predict the future. Extremists like Guy Macpherson aver that it is already too late and the earth will become void of all large plants and animals inevitably in the next century if not decades. I agree this could happen, although from what I read of climate science, even given very alarming evidence of accelerating ice cap melting etc, it still doesn't seem a foregone conclusion. But even if not, it's a likely outcome, in centuries if not sooner. What rational species would continue on the same path given this information? None of course, which just goes to show that mankind is not as rational as it tends to claim it is. From the basic theory of evolution, I presume that all species have a drive to grow and expand in numbers, and that any limits are imposed only by the external environment not by any evolvable behavior. That bodes poorly for mankind. The tragedy is that the same evolutionary forces have given us minds that are capable of imagining such a future. If only those minds were strong enough to allow us to modify our actions to contradict the deeper biological drive to expand, grow, reproduce. But I fear not, ever or anytime soon at least. The question is whether we can survive as a species until we mature sufficiently to attain such mastery over basic evolutionary impulses.