I asked my freshman seminar to write an essay about energy use in the US in the past 50 years based on this EIA data table showing GDP in 2000 dollars, energy consumption in BTUs, population, and other stuff. Here’s what I (and they) learned from the experience.
Total energy consumption in the US has increased over the past 50 years. The only time it decreased was in the mid-1970s, as a result of the OPEC oil embargo and the resulting economic recession.
However, energy consumption per $ of GDP has consistently, if not steadily, fallen over the same time period. This fact indicates that we get more economic bang for the buck out of each BTU of energy we consume. In fact, BTU/$GDP has fallen by about half in the past 50 years, meaning that it takes half the energy today to generate a dollar of economic value that it took in 1949. Technological change plays an important role in this story, as does the structural shift in the US economy toward production of services and away from manufacturing.
Energy consumption per capita, however, has generally increased, even though population in the US has been growing. This fact suggests that the energy consumption growth rate is generally larger than the population growth rate over the past 50 years. Again, this should not be surprising if you consider the lifestyle changes that have occurred since then — cars, appliances, computers, televisions …
To me the most valuable insight from this exercise is to see how much more economic value we generate today using a given amount of energy than we did a half century ago.
UPDATE: Thanks to David Stone for the link to this Economist article commenting on the current situation of the world oil markets in a historical perspective.