Mean perceptions of energy used or saved as a function

of actual energy used or saved for 15 devices and activities. The diagonal

dashed line represents perfect accuracy. Inset: Individual regression

curves for 30 randomly selected participants. Source: Attari et al. Click to enlarge.

A new survey by researchers from Columbia University, Ohio State University and Carnegie Mellon University finds that many Americans have a very poor understanding of energy use and savings. Many of the 505 participants believed they can save energy with small behavior changes that actually achieve very little, while severely underestimating the major effects of switching to efficient, currently available technologies. The study appears in this week’s Proceedings of the National Academy of Sciences.

The largest group, nearly 20%, cited turning off lights as the best approach—an action that affects energy budgets relatively little, according to the researchers. Very few cited buying decisions that experts say would cut US energy consumption dramatically, such as more efficient cars (cited by only 2.8%), more efficient appliances (cited by 3.2%) or weatherizing homes (cited by 2.1%).

Previous researchers have concluded that households could reduce energy consumption some 30% by making such choices—all without waiting for new technologies, making big economic sacrifices or losing their sense of well-being.

Notwithstanding a few bright spots (e.g., knowing roughly how

much energy is saved by a CFL), participants in this study exhibited

relatively little knowledge regarding the comparative energy use

and potential savings related to different behaviors. Relative to

experts’ recommendations, participants were overly focused on

curtailment rather than efficiency, possibly because efficiency

improvements almost always involve research, effort, and out-of-pocket

costs (e.g., buying a new energy-efficient appliance), whereas

curtailment may be easier to imagine and incorporate into

one’s daily behaviors without any upfront costs.

Participants were also poorly attuned to large energy differences

across devices and activities and unaware of differences for some

large-scale economic activities (transporting goods by train vs.

truck) and everyday items (aluminum vs. glass beverage containers).

Knowing these relative magnitudes would allow individuals to

make more informed choices regarding energy-saving behaviors.

—Attari et al.


Mean perceptions of energy used for automobile-related activities (A), and saved via modes of transporting

goods (B). Source: Attari et al. and Click to enlarge.

Previous studies have indicated that if Americans switched to better household and vehicle technologies, US energy consumption would decline substantially within a decade. Some of the highest-impact decisions, consistently underrated by people surveyed, include driving higher-mileage vehicles, and switching from central air conditioning to room air conditioners.

In addition to turning off lights, overrated behaviors included driving more slowly on the highway or unplugging chargers and appliances when not in use. In one of the more egregious misperceptions, according to the survey, people commonly think that using and recycling glass bottles saves a lot of energy; in fact, making a glass container from virgin material uses 40% more energy than making an aluminum one—and 2,000% more when recycled material is used.

Many side factors may complicate people’s perceptions. For instance, those who identified themselves in the survey as pro-environment tended to have more accurate perceptions. But people who engaged in more energy-conserving behaviors were actually less accurate—possibly a reflection of unrealistic optimism about the actions they personally were choosing to take.

On the communications end, one previous study from Duke University has shown that conventional vehicle miles-per-gallon ratings do not really convey how switching from one vehicle to another affects gas consumption (contrary to popular perception, modest mileage improvements to very low-mileage vehicles will save far more gasoline than inventing vehicles that get astronomically high mileage). Also, said Attari, people typically are willing to take one or two actions to address a perceived problem, but after that, they start to believe they have done all they can, and attention begins to fade. Behavior researchers call this the single-action bias.

Many people’s concerns about energy are simply not strong

enough, relative to their other concerns, to warrant learning about

energy conservation. Although it may be appropriate to criticize

the media for not presenting the case for climate change more

strongly and for not presenting the implications of individual behavior

more clearly , scientists share at least some of the responsibility

for the current state of affairs. For example, Fischhoff

recently argued that scientists may have failed the public by not

providing information in a credible and comprehensible manner to

facilitate better climate-related decisions. In addition to improved

communication efforts, increasing fossil fuel prices to reflect the

true environmental costs of CO2 emissions would also provide

strong incentives for learning and behavior change.

Research has demonstrated that successful risk communication

requires an understanding of people’s knowledge gaps and misconceptions, and the same is likely to be true for communications

about energy. The results of this study imply that well designed

efforts to increase the public’s knowledge of energy use

and savings could be quite beneficial, although we hasten to add

that providing appropriate information is only one component of

a successful intervention strategy and that other barriers

to individual emissions reductions must also be addressed.

Recent research indicates that investments in non–price-based

behavioral interventions can be effective in decreasing energy use. However, many campaigns have focused on behaviors that

save relatively small amounts of energy, such as unplugging one’s

cell phone charger, whereas other more effective behaviors have

been neglected. So long as people lack easy access to accurate

information about relative effectiveness, they may continue to believe they are doing their part to reduce energy use when they

engage in low-effort, low-impact actions instead of focusing on

changes that would make a bigger difference. If people are uninformed,

the substantial potential of behavioral interventions to

reduce energy consumption may go unrealized. It is therefore

vital that public communications about climate change also

address misconceptions about energy consumption and savings, so

that people can make better decisions for their pocketbooks and

the planet.

—Attari et al.


  • Shahzeen Z. Attari, Michael L. DeKay, Cliff I. Davidson, and Wändi Bruine de Bruin (2010) Public perceptions of energy consumption

    and savings. PNAS Early Edition doi: 10.1073/pnas.10015091