Slate: It is widely assumed that over the coming decades, increased energy efficiency will help the world meet its energy needs and reduce carbon emissions. That may be true, but recent research suggests that energy intensity--a widely used way of measuring efficiency--isn't the right metric.
Energy intensity is a simple ratio: energy use per dollar of GDP. According to the U.S. Energy Information Administration, the energy intensity of the U.S. economy declined by 1.6 percent per year from 1985 to 2004,...