Doing the Car Math

In his latest Do the Math post, physicist Tom Murphy estimates that total human energy use, in all forms across the whole globe and its 7 billion inhabitants, is something like 13 TW (TW = terawatts, or trillion watts). Murphy also calculates that the United States’ annual use of 7 billion (yes, it’s the same number now as the planet’s population) barrels of petroleum constitutes an energy burn of 1.3 TW, or ten percent of total human power use.

For those tracking the insanity of cars-first transportation, this suggests a few follow-up calculations.

We know that, as of 2009, 72 percent of U.S. oil use was in the form of transportation fuel. We also know that some additional petroleum is used both to build automobiles and to build and maintain asphalt roads for automobiles, so the true share of U.S. oil use explained by cars and trucks is certainly at least 75 percent.

Since the United States burns 10 percent of humanity’s total current energy budget on oil, and since cars-first transportation accounts for at least three-quarters of total U.S. oil use, then oil-based transportation in the United States devours 7.5 percent of humanity’s total energy budget.

At present, the population of the United States is about 4.5 percent of Earth’s human population.

Interestingly, the 59 percent of the total U.S. oil burn that goes into personal cars and trucks works out (.59 times 7.5) to 4.4 percent of total world energy use, meaning that, if energy use were distributed fairly across the planet, the U.S. fleet of personal-use automobiles would be devouring the nation’s entire per-capita share.

This, of course, doesn’t include the gas and diesel fuel that gets used in the country’s cargo-delivery trucking system. Much or all of the long-distance trucking sector exists as a way to break and preempt labor unions and thereby restrain labor expenses/incomes, as long-haul truckers are about as disinclined to form unions as railroad workers are prone to forming them.

The President who happily signed the most recent major legislation encouraging the ascendance of long-haul trucking over railroad freight, the Motor Carrier Act of 1980, despite the obvious energy inefficiency of trucks compared to trains? Nope, not Reagan. Our old friend and darling of phony-green false history, one James Earl Carter, Jr.