penciling it out

One almost has to be deaf and blind not to conclude that the writing is on the wall, dare I say it, that we're nearing the end of our civilization. Proving it to a faretheewell is a little harder, but not so if one makes one very plausible assumption, that technological breakthroughs won't save the day. The assumption is plausible because we humans are very clever to have gotten to where we are already. But remember also, as Kunstler puts it in The Long Emergency:

we tend to confuse and conflate energy and technology. They go hand in hand but they are not the same thing

In the same paragraph, Kunstler adds:

Much of our existing technology simply won't work without petroleum, and without the petroleum "platform" to work off, we may lack the tools to get beyond the current level of fossil-fuel based technology.

[even if, a big if, otherwise possible]

Another way of putting it is that we have an extremely narrow window of opportunity to make that happen.

Two hoped-for breakthroughs are nuclear fusion and cellulosic ethanol. Physicists have been trying to harness fusion for decades without much success. Richard Heinberg talks about the difficulty in his book, The party's over: oil, war and the fate of industrial societies.

To sustain our wonderful American lifestyle, we use up a lot of oil, about 25 barrels* per American per year. We burn most of that up for energy and most of that as liquids in transportation. (Let us also not forget how dependent we are on plastics.) Remember that the energy-dense oil we extract from the earth is solar energy concentrated over vast amounts of time. Is it reasonable to expect that we can harness the diffuse solar energy that impinges on the U.S. in sufficient quantities to replace that which has accumulated in the earth over eons? What kind of infrastructure, with how much in the way of energy inputs, would be required? It's questionable even whether corn kernel ethanol, with its massive government subsidies, has a positive EROEI. There seem to be biophysical limits to cellosic ethanol which make it more problematic than from sugar-based ethanols. Further, there are reports about problems with the mono-cultured sugarcane-based ethanols from tropical Brazil.

We need a substantial permanent harness-able energy source, along with the technology to store and transport that energy. Even if those were theoretically available, we need the energy, will and time to get to such a place, all in short supply.

* - 25 barrels per American per year doesn't sound like a lot, but when you consider that we Americans use 25% of the world supply, that amounts to 1000 barrels per second extraction worldwide.

Running the Numbers: An American Self-Portrait
For some basic energy numbers, see this PDF from the University of Washington, School of Oceanography.