Why Reducing Emissions Is So Hard

It seems we humans tend to sabotage our own climate-improvement efforts.

The findings revealed two surprises. First, state governments' policies aimed at helping consumers improve energy efficiency had no effect on CO2 emission. Rather, states with economy-wide lower energy input per each unit of economic output (per capita gross domestic product, GDP) emitted lower levels of the greenhouse gas. Second, investment in renewable energy sources led to increased levels of CO2 emissions in the residential sector. These outcomes are evidence of a well-known phenomenon called the rebound effect that describes when people respond to saving energy by consuming more, negating the benefit of CO2 reduction.

"Lots of energy analysts tend to look at emissions as a technical problem that requires a technical solution; build more efficient vehicles, build homes to use less energy. What they don't consider is human behavior. If you've got a hybrid car, the money you save on gas might allow you to drive more," said the study's lead author Lazarus Adua, assistant professor of sociology at the U. "My goal here is to let policymakers know that this rebound effect is a problem, and they need to address it. If you're only paying attention to improving efficiency and investing in renewables, you're not going to solve the problem."