Date of Original Version

Summer 2009



Abstract or Description

Efficient technology that requires less energy than is currently used to get the same or better output has fueled the growth of our economy for more than a century. But while America was building its infrastructure and developing its industry and service sectors, the energy intensity of the economy, BTU per dollar of output, fell dramatically. If this had not happened, it would now take four times as much petroleum, coal, and natural gas to produce current GDP, at the 1919 energy-intensity level. This would amount to 85 percent of the current world production of fossil fuels—just to support the U.S. economy. Producing, transporting, and using that much energy, even if it were technically feasible, would devastate the natural environment and contribute to carbon dioxide emissions that would exceed the atmospheric concentration some scientists think would be catastrophic.



Published In

The Bridge: National Academy of Engineering , 39, 2, 5-14.