We all know carpooling is good for the Earth. So highway departments build high-occupancy vehicle lanes and companies offer prime parking spaces for employees who share rides.
But carpooling is unlikely to save the environment. It's too hard.
So say scientists who have studied how people confront environmental and energy challenges. Carpooling, they say, has low "plasticity" -- that is, people are unwilling to do it -- so its "reasonably achievable emissions reductions" are low, as well.
Unfortunately, that is not how U.S. policymakers see it.
"We tend to fund efforts that appear to have, on the surface, the greatest potential emissions reductions," said Mike Vandenbergh, director of Vanderbilt University's Climate Change Research Network. "A real value is in looking not just at potential emissions reductions, but also at plasticity. Because otherwise, you'll be frustrated."
Carpooling, it turns out, is frustrating. Vandenbergh was part of a research team that examined 17 environment-saving behaviors, finding carpooling the second most effective in potential energy savings but dead last in potential consumer uptake. Their paper was published last month in Proceedings of the National Academy of Sciences (E&ENews PM, Oct. 26).
The study's finding: "Reasonably achievable" behavioral changes can cut U.S. emissions of heat-trapping carbon dioxide within a decade by an amount equivalent to the total emissions of France or the U.S. petroleum refining, iron and steel, and aluminum industries.
The work is lowbrow and low-tech, but effective. Sealing leaky windows, switching to low-flow showerheads, making sure car tires are inflated properly, regular auto maintenance and similar changes can reduce U.S. carbon emissions by 7.4 percent yearly, the study says.
But to craft a large-scale plan for promoting such behavioral shifts, scientists have a lot more work to do, Vandenbergh said.
For example, his group tried to assess the impact of turning down home water heater temperature settings, but found a dearth of information on what temperature settings people use. Without that information, he said, it is difficult to measure the room for improvement.
"We're trying to set up a framework to help policymakers and researchers take a more systematic approach," Vandenbergh said in an interview. "Regulating industrial emissions would be very systematic. Changing behavior should be just as systematic."
Case study: California
The 2001 California energy crisis served as a laboratory for studying energy-related behavior changes.
When power shortages led to statewide price spikes and rolling brownouts, utilities and state and local governments worked together to reduce power use and keep the lights on.
Government officials were surprised at how much individuals changed their behavior to save energy.
Responding to a variety of stimuli -- including a publicity campaign called "Flex Your Power," financial incentives, news reports and direct appeals from public officials -- Californians reduced their electricity use by nearly 7 percent from the previous year, adjusted for weather and economic change, according to the California Independent System Operator. Peak summer demand dropped by between 8 and 14 percent.
Loren Lutzenhiser, a professor of urban studies and planning at Portland State University who studied the crisis and California households' responses, found that while many people followed traditional paths like buying more efficient light bulbs and upgrading equipment, the biggest share of energy savings came from behavior change.
Turning off lights, unplugging equipment and adjusting thermostats to use less air conditioning accounted for 84 percent of the drop in energy use, Lutzenhiser reported in a study commissioned by the California Energy Commission and based on telephone surveys conducted in 2001 and 2002.
The 2001 survey found that 71 percent of households said they had taken at least one "conservation action," while 30 percent reported doing three or more things to save energy.
And while conventional wisdom would point to financial concerns as the biggest driver of energy efficiency, Lutzenhiser found that civic responsibility, altruistic motives like protecting the environment and using natural resources wisely and "doing one's part" were reported widely as motives.
Among those who did not change their behavior, most said it was because they felt they already used a low amount of energy.
The California results surprised many in energy policy circles. They had long assumed that cost-driven, technology-based measures were the best bets for trimming home energy use. Lutzenhiser points to the history of energy policy to help explain why behavior changes are downplayed today.
In the 1970s and 1980s, Lutzenhiser said, equipment change was the preferred conservation measure because it was predictable and produced reliable results. The human factor was seen as too difficult a policy target, he said.
Adding to that, he points out, policymakers were conscious of the ridicule directed at President Carter after he suggested during the 1978 energy crisis that Americans turn down thermostats and conserve power. "There is simply no way to avoid sacrifice," Carter said.
Eventually, conservation lost favor, with plainly economic, cost-benefit-based decision-making taking its place as the primary means by which consumers were understood to approach energy use.
Ed Vine, an energy analyst for Lawrence Berkeley National Laboratory who works on energy efficiency program evaluation, said the California crisis brought to light some important points for researchers.
"Even though there were a lot of messages going out [to Californians in 2001], a lot was to get people to buy energy efficiency equipment with rebates, so I would have expected more of that," Vine said. When the time came to change on a dime, though, the data showed it was easier to affect behavior.
Vine said social scientists are critical of policy models that focus exclusively on financial drivers because energy use is, in the end, very much a social undertaking.
"There are habits, and customs, and cultures, and attitudes that need to be changed," Vine said. "And sometimes, people can be convinced quickly; other times, it takes a long educational effort to make them aware."
Companies see market potential
While policymakers have been cool toward cultural change approaches, businesses have noticed the emerging research.
Trading on studies that show how making energy information available to consumers can promote behavior change, many vendors are offering gadgets that track power use.
GreenRoad is among those vendors. The Redwood Shores, Calif., company is selling a device that coaches drivers based on real-time measurements of acceleration forces, providing indicator lights that signal driving safety and fuel efficiency. The company also markets services that report individual vehicle data to a central dispatcher for remote tracking and fleet management.
GreenRoad maintains that using the device can reduce crash risk by as much as 50 percent and trim fuel use and associated emissions by up to 10 percent, with the potential to alter driving habits in the long term.
The 10 percent figure is a common milepost among behavioral approaches. Studies consistently show that just seeing timely information about energy use is enough to spur cutbacks of about that same amount.
Many expect that over the coming decade, utilities will convert to "smart meters" that track minute-to-minute electricity use. Combined with time-of-day pricing and "smart" appliances, utilities will let consumers manage their energy bills.
Companies are already pitching information-based home energy-detection devices. Among them is Charleston, S.C.-based Energy Inc., which makes a device it calls TED -- an acronym for "the energy detective" -- designed to monitor home energy use second by second. TED costs $200 and hooks into a home's electrical system. The company claims the device will register a power jump when you open the refrigerator door and the light goes on.
Researchers say energy-saving behavior is boosted when people are told not just how they can cut back but that others are already doing so.
Psychologist Robert Cialdini researched campaigns at hotels aimed at reducing laundry bills by asking guests to reuse towels. He said appeals relying on descriptive social norms -- messages that say other guests reuse their towels at high rates -- were most effective at spurring people to do the same.
"Commercial decision-makers commonly base important program or policy choices on thinking grounded in the established theories and practices of a variety of business-related fields," says a paper written by Cialdini and published in Observer, a journal of the Association for Psychological Science. "What is vexing is how seldom these decision-makers avail themselves of established psychological theories and practices."
Some home energy monitoring systems do try to take advantage of that principle. Google Inc.'s software-based monitoring system, PowerMeter, for example, displays how a home's energy use compares either to historical use patterns or to the energy use of a "typical" home of the same size.
Everyone is doing it
Vanderbilt University's Vandenbergh said that if policymakers really want to lower energy use, they would do well to integrate social science systematically into project design.
"In the long run, to take advantage of the opportunities for low-cost, prompt carbon emissions reductions, agencies will need to be staffed to include people who understand not just the economics of behavior but the other social science components of behavior," Vandenbergh said.
Politicians have a responsibility to convey the importance of individual behavior, he added, noting that President Obama has mentioned the importance of personal responsibility in energy use.
"Once we have enough information to understand how large the opportunity is, individual behavior change should be something that appeals across the political spectrum," Vandenbergh said, because it can offer an alternative to relying on government programs.
In Europe, there are signs that decision-makers see the connection. Paul Stern, director of the U.S. National Research Council's Committee on the Human Dimensions of Global Change, said European governments show a greater interest in research and policy that integrates behavioral science.
"They are trying to use policy to change behavior in a more extensive way than is happening here, and there is more social research on this topic in Europe than here," Stern said. "But the link between the two, I think, is still being forged."
The message to U.S. policymakers: Others are doing it; why not you?
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