Higher levels of energy efficiency does not decrease demand. Instead it increases it. This counter-intuitive effect is called rebound. Thus, expected energy savings and reductions in emissions from better efficiency are substantially less than might be expected.
The IPCC made clear: climate mitigation strategies that heavily rely on energy efficiency measures must be re-evaluated. After years of simplistic accounting, which was roundly criticized by Breakthrough and independent scholars, the IEA has finally caught up to the academic literature. Their latest report, Capturing the Multiple Benefits of Energy Efficiency, acknowledges that direct rebound in wealthy countries ranges from zero to 65 percent and agrees with a major modeling effort finding globally averaged rebounds from energy efficiency could reach as high as 52 percent by 2030.
“Rather than saving energy, in many cases we can expect the adoption of energy efficiency-improving technologies to contribute to processes that lead to an overall increase in energy consumption.”
This pattern is similar to water use in the Imperial Valley of California. Big agriculture is constantly and successfully finding ways to grow crops with less water per acre. However, water usage there is increasing because farmers simply plant crops on more land. Water usage per acre has dropped. The number of acres growing crops has increased. The same process is true for energy usage. Increase efficiency and demand increases too.