Thoughts about Gasoline

One of the primary points in Bill McKibben's Deep Economy is that work and transportation were transformed by the rise of the use of fossil fuels. Instead of human (or horse) effort to farm crops or move cargo, petroleum was used instead. McKibben writes,

The number of farmers has fallen from half the American population to about 1 percent, and in essence those missing farmers have been replaced with oil.

Petroleum releases an incredible amount of energy from a small quantity. We are so used to it, though, we don't even realize how amazing it is.

Think of this: If you have a car that gets kind of average gas mileage -- 25 mpg -- you can put four people in it, plus all their luggage, and move that one-and-a-half ton vehicle 25 miles on just one gallon of gas...which weighs about eight pounds and takes up maybe half a cubic foot of space.

You would traverse that distance in less than half an hour (at 60 miles per hour), or maybe an hour if you were going at city street speed.

25 miles is about the distance that a horse pulling a wagon could go IN A DAY. And the horse would need to eat some amount of oats or hay and drink some water, probably significantly greater in volume than the gallon of gas, I imagine.

So that single gallon of petroleum-based liquid can do an amazing thing, which I, for one, generally do not appreciate.

Too bad burning it creates pollution and releases carbon into the atmosphere that had been buried underground. But you can see what we're up against when it comes to replacing petroleum fuels with anything else. They pack an incredible amount of energy into a very small and portable medium.

On a side note that also involves gas tanks and the number 25: this morning, I heard on the Marketplace Morning Report that the amount of corn it takes to make 25 gallons of ethanol (enough to fill the tank of an average SUV) could feed a person for a year. This was according to Lester Brown of the World Watch Institute.