On Climate, Symbols Can Overshadow Substance

A hot-air balloon promotes this year's Earth Hour as it floats over Sydney Harbor in Australia. (By Mark Kolbe -- Getty Images)

Once a person buys a house in the exurbs, for example (or once officials approve such a subdivision), asking people to think about the environmental costs of commuting isn't very effective, because they are already locked into lengthy commutes. In the same way, installing motion sensors that automatically turn lights off at night produces far larger energy savings than depending on people to switch them off.

"Depending on people to make a hard choice every day -- don't turn on the lights so much -- is a less-promising solution than getting people to make a hard choice once," by paying more for a high-efficiency bulb, "and thereafter having the 'save energy' decision be automatic," said Travis Reynolds, a graduate student at the University of Washington in Seattle who studies how societies save energy.

Reynolds's argument is supported by the numbers: Let's say people participating in Earth Hour have 10 100-watt light bulbs in their houses, on average. If you also assume that high-efficiency compact fluorescent bulbs last three years and use only 25 percent of the energy of conventional bulbs, you would have to persuade more than 400 people to turn off their lights for an hour to get the same energy savings as persuading one person to switch one conventional bulb to a high-efficiency bulb.

Gary Flomenhoft, an economist at the University of Vermont, said his state's decision to set up a public utility whose sole job is to reduce energy consumption produced huge savings in energy use, most of which had little to do with individual acts of virtue. The utility goes into businesses and homes and helps people figure out practical ways to save energy. As a result, Burlington today uses the same amount of energy it did in 1989.

"Some people react to ethical and environmental concerns, but a vast majority of people react to price," Flomenhoft said. "The biggest effect on people's behavior is price. When gas reaches $4 a gallon, everyone talks about hybrids."

As gasoline prices have soared in recent months, the number of people using public transportation has risen sharply, as has interest in fuel-efficient cars. While the U.S. trends are a result of market-driven prices, many European countries have obtained the same results by raising the price of gas through taxes.

The powerful role of structural factors also explains why some personal sacrifices count more than others. When it comes to turning off lights, for example, Earth Hour would have produced far more energy savings -- although no cool photos of darkened cities -- if it had asked people to save energy during the late afternoon, rather than at 8 p.m.

That is because energy use fluctuates during the day. There are times when power companies bring more plants online, and times when plants are taken offline. In general, said Denny Ellerman, an energy and environmental economist at the Massachusetts Institute of Technology, large energy savings are produced when energy is generated and used in a steady manner.

"The more a power plant operates steadily, the more efficient it will be," he said. "To the extent you can shift the peaks toward the valleys, you are going to improve the efficiency."

Richard Kafka, manager of transmission policy at Pepco, said usage in the Washington area is highest between 4 p.m. and 8 p.m., and lowest between midnight and 4 a.m.

"Which is smarter -- running on level ground or running up and down a hill?" Kafka asked. "There is a characteristic of heat engines that they are most efficient at some point, and anytime I move off that I am less efficient."

Borenstein, at the University of California, said he recently decided to take his own advice about focusing on measurable outcomes. He bought a device called a Kill-o-watt, which can measure how much energy is used by appliances and electronics, and took it around his house to look for savings.

"It turned out the TV and VCR in our guest room, which is almost never used unless I am exercising, uses 17 watts all the time when it is plugged in, and it does this 24 hours a day, seven days a week," he said. By unplugging the devices when they are not used, Borenstein found he could save nearly 150 times the amount of energy that a household with 10 100-watt light bulbs would save by turning them off for an hour.

"We are not going to solve this problem with voluntary measures -- it is a problem of externalities," he said. "It is true of pollution and the way we use oil. We address tailpipe emission problems by asking people to make sure they meet emission requirements -- we actually check. We have found voluntary approaches don't work when it comes to pollution."