Of equal interest is the extended comment on Eschenbach's essay from rgb@duke, a professor of physics at Duke University. He makes the intriguing case that future sources of energy are essentially unlimited. Since you may not scroll down through the comments, I've reprinted it below.
A few small notes. Looking at the table, there is a difference between “reserves” and “recoverable resources”. We have 81 years of the former, but well over ten times that in recoverable resources. The former has proven to be a rather flexible and hence perhaps pointless number as it keeps changing as new resources are discovered and proven, which is why we haven’t reached “the end of oil” quite yet. In particular, there is a LOT of coal that is recoverable, and nothing prevents us from using a venerable process for converting coal into gasoline but price — the general availability of cheaper gasoline produced directly by refining crude oil.
Second, you deliberately (I imagine) did not address nuclear energy and its reserves. Uranium is problematic — perhaps — because high pressure light water cooled reactors have technical risks of meltdown and associated risks of nuclear proliferation, but nevertheless there are at least hundreds, possibly tens of thousands thousands of years worth of Uranium reserves (the latter if we use breeder reactors and actually burn all of the Uranium instead of a pitifully small fraction of lightly enriched U-235). Of course breeder reactors that are efficient in this regard burn plutonium for most of the energy they produce, and plutonium is bomb material at this point for pretty much any country that gets it as the concept of implosion lenses and critical density is hardly either secret or technically inaccessible any more even to a very poor and backwards country. Still, we have 30,000 years of Uranium WITHOUT using Uranium from seawater from proven reserves if we use breeder reactors. If anyone works out how to economically extract Uranium from seawater we have an effectively infinite supply — humanity would evolve before we ran out, as the 60,000 years in seawater would be amplified by 100 to 6 million years. Admittedly, this is “at current consumption rates” so it would be less if we converted over to using fission reactors on a broad basis, but I think that it makes the 81 years entirely moot.
Third, that doesn’t include Thorium, either. Thorium has a number of advantages over Uranium as a reactor fuel, the principle ones being that it is somewhat (but not decisively) more difficult to use as the basis for a clandestine bomb building program, it produces anywhere from 10 to 10,000 times less nuclear waste depending on the fuel cycle selected, and it is MUCH more difficult to make a thorium reactor “melt down” the way existing solid-fuel LWR Uranium designs can. The most advantage fuel cycle appears to be liquid salt reactor designs, which literally cannot melt down, have reduced (but nonzero) proliferation concerns, and which could literally be used to burn EXISTING nuclear waste and in the process would release a lot of the unburned energy in existing spent nuclear solid fuel (currently only around 1% of the available energy is being recovered in LWR Uranium non-breeder designs). Estimates of thorium reserves and available energy necessarily vary because only prototype reactors have been built of the various kinds and because little effort has been put into developing Thorium reserves (Thorium is currently a radioactive waste byproduct of mining rare earth metals and has only a handful of industrial/commercial applications as things now stand) but it is at LEAST tens of thousands of years. As a side effect of adopting Thorium as an energy fuel, we would completely solve the problems with global shortages of rare earths and hence e.g. rare earth magnets and exotic semiconductors, both essential components in other aspects of efficient energy production and transmission and utilization.
I know that we don’t necessarily agree on the eventual utility of solar power, but IMO there is also no question at all that over the next decade or two solar cell technology and engineering will progress to where the cost per watt at over the counter retail rates drops below fifty US cents (to as low, eventually, as ten cents or even less). This will correspond to wholesale prices that are roughly half of these retail prices. This will push the amortized cost recovery for large and small scale solar energy projects to well under a decade, with an expected plant lifetime of at least twice that, and IMO will make solar a no-brainer energy resource for the entire tropical and subtropical band. Although without efficient energy transportation and storage (which are both more speculative and less predictable) solar alone is not a viable single energy resource for a steady state global civilization such as the one you propose, they can easily eke out both nuclear and carbon-based resources and double or triple any of the numbers above for years of available energy.
If (say) high temperature superconducting transmission lines are discovered/invented that facilitate the transport of electrical energy distances on the order of 10,000 miles with minimal loss, and/or high capacity high efficiency multicycle energy storage is ever worked out (say zinc oxide batteries are eventually developed that have charged energy densities that are roughly comparable to gasoline) it would both permit the eking out of “fossile” resources (carbon, Uranium and Thorium) to “indefinitely long” and could even serve as the basis for a truly steady state civilization, which I believe should be our long term goal regardless of greenhouse issues.
Finally, on the speculative front, is low temperature fusion. Fusion in some sense is the holy grail of energy production mechanisms. If economically feasible deuterium-based fusion is ever worked out, we will literally never run out of energy. It would take us tens of millions of years of utilization to BEGIN to deplete deuterium even if you provided energy to every person on Earth at levels equal to or in excess of US consumption per capita, and with that much energy we could cost-effectively mine e.g. Europa, Titan and the gas giants if we should ever actually significantly deplete the Earth’s oceans. A mix of solar and fusion energy production would make the human species secure well past the point where it is no longer recognizably human, time frames longer than the interval from the end of the Cretaceous to the present, geological time scales. The human species might well die off over that sort of time frame, but probably not because we ran out of energy. To ensure survival of the species even beyond that would likely require at least interplanetary if not interstellar colonization, and still more speculative advances in physics and technology for the latter to become even imaginatively possible.
Otherwise, yes, I agree, we have little excuse for not ending energy poverty worldwide. Nor do I think Spain/Italy should be the standard — our goal should be lifting people up to e.g. the rate of energy utilization in the US. Eliminating poverty might actually facilitate a reduction in the rate of population growth or even initiate a period of population decrease, and that too is a way of extending and improving per capita consumption. Finally, there is a world of undeveloped technology that might reduce per capita consumption without impacting quality of life. The past conversion from incandescent to CF light bulbs, the future conversion from CF to LED bulbs (that use still less energy and have far longer lifetimes) are a prime example. Houses that use integrated local solar for local daytime AC are another. Smart houses that deliver e.g. light or AC only when and where it is needed (without loss of comfort or utility) yet another. A lot of this is technically feasible right now; it simply isn’t implemented because the cost-benefit is marginal with energy being as CHEAP as it is, but as energy prices increase over time, the marginal return from these technologies and their broader implementation and economy of scale will greatly reduce the real dollar cost and eke out our energy resources further still.
It would be a whole lot easier to establish a stable and sustainable global civilization with a billion humans than it is or will be with 7+ billion humans. OTOH, I’m not quite ready to go out there and pick 6+ billion humans to be “culled”. Nature — via pandemics, asteroid collisions, ice ages — might do it anyway. Or, we might get there by simply improving the standard of living worldwide to the point where humans (apparently) stop reproducing at rates that lead to population growth, and then gradually ramp it down by having fewer babies than people who die of natural causes for a century or two.
Either way, I won’t be around to watch most of this, probably. Interesting to think about, though.
rgb
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