This is the third in a series of articles addressing the USA’s energy situation (...see article 1 here, article 2 here).
In the previous article I pretty much laid down the following as an axiom:
A growing economy requires growing energy input.
Since then, I’ve received five emails (four friendlies, one smart-alec) questioning that assertion—and they all point to our nation’s track record of steadily improving energy efficiency, year by year. Although they are all correct that we have established a long track record of using energy more and more efficiently to generate each dollar of GDP, the axiom above still stands.
Two pictures are worth two thousand words. Chart 1 shows “Energy Efficiency.” Click to enlarge.
Since 1947, the (real) economy has grown at a 3.47% average annual pace, and energy efficiency has improved at a 1.37% annual pace. Compared to 1947, we now use less than half the amount of energy for each dollar of GDP. That’s good.
Chart 2 adds “Total energy consumption” to the mix. Click to enlarge.
Total energy usage (Quadrillion Btu’s consumed by our economy) grew at a 2.05% annual pace. Compared to 1947, we now use three times as much energy to drive our (much bigger) economy. We're lighting a lot more 10' x 10' rooms at night—a lot more effectively and efficiently per room. We're moving a lot more tons of consumer goods cargo to the store shelves—at a much higher efficiency per ton of cargo.
I hope that clarifies the point, which bears repeating:
A growing economy requires growing energy input.
Also, please note the question mark next to the word “Future” on each chart. It’s important—because even though extrapolating the past is usually about the best anyone can do in the forecasting arena, I can guarantee that things will not unfold that way. Changes come in surprising spikes with surprising timing, and that’s what will happen in energy. (The “Peak Oil” folks are counting on a bad-news spike, by the way. Others of us think the opposite kind of spike just might be possible, and some of us even think our nation might have a little influence over the timing of a good-news spike. More on this in future articles.)
Lastly: In the first article of this series, I estimated we’d be using 250+ Quads in twenty years. That was probably too high, as the chart indicates—unless future economic growth is a lot higher than 3.5% (...a distinct possibility, if Ray Kurzweil is correct that we're now at "the knee" of an exponential growth curve).
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Here are links to all seven articles in the energy series:
• Article 1: Energy facts, certainties, and possibilities
• Article 2: Government spending and its consequences
• Article 3: Yes, growth DOES require more energy
• Article 4: Dissenting from Mr. Gore
• Article 5: The obstacle to oil independence
• Article 6: A tankful of electrons
• Article 7: A 21st Century “GI Bill”
