For decades, Girl Scouts have pledged to make the world a better place. Now there’s scientific proof that they do.

After completing five hourlong courses on energy conservation, Junior-level Girl Scouts boosted their households’ energy-saving activities by as much as 49 percent, according to a study published today in the journal Nature Energy.

They didn’t stop there. In one of the courses, the fourth- and fifth-grade girls also prompted their parents to increase their conservation behaviors by up to 12 percent.

The Girl Scouts’ success in this unique clinical trial demonstrates that children have the potential to serve as agents of change for their entire families, Hilary Boudet, an assistant professor at Oregon State University’s School of Public Policy, and her colleagues concluded.

Americans could certainly use the help. According to the U.S. Energy Information Administration, U.S. households account for 21 percent of the world’s energy use, despite making up about 4 percent of the world’s population.

The energy-conservation course — Girls Learning Environment and Energy, or GLEE — was developed at Stanford University. It encourages girls to save energy by having them practice skills, like making sure charging cords were plugged into power strips. Also, by rehearsing these skills with their fellow Girl Scouts, the girls reinforced one another’s motivation to follow through with their new skills at home.

The GLEE team invited Girl Scout Junior troops from Santa Clara, San Mateo and Alameda counties to try the program. Fifteen troops were randomly assigned to a course focused on saving energy at home, and 15 were assigned to a different course examining energy use related to food production and transportation. Altogether, 327 Girl Scouts and 303 of their parents tried one of the two programs.

In both cases, the Scouts created a fake newscast about energy conservation. As part of their newscast, the girls demonstrated and filmed examples of energy-saving behaviors. It took between eight and 12 weeks for most of the troops to complete the training.

The course focused on energy conservation at home was the more effective of the two, survey data showed. By the time the training sessions were over, the girls who had increased their residential energy-saving activities by 49 percent — a change the researchers were able to measure by using the girls in the food and transportation course as controls.

Eight months later, the girls who were trained in residential conservation techniques were still applying what they had learned — their energy-saving behaviors were up 27 percent compared to where they had been before the course began.

The biggest changes they made in their homes included turning off power strips at night, changing the temperature settings in their refrigerators and using cold water in the washing machine.

Surveys of parents revealed that the moms and dads of these Girl Scouts were also doing more to save energy as a result of their daughters’ training. By the end of the course, parents’ energy-saving behavior had increased by 12 percent compared to the pre-training baseline. Nine months later, their conservation efforts were still 6 percent higher than they had been at the start of the study.

The parents were most likely to make improvements by adjusting the temperature of their refrigerators and water heaters, and by air-drying their clothes instead of using a dryer.

The course about ways to save energy by modifying eating and transportation behaviors didn’t have quite the same effect. When the training was over, the girls in this group increased their energy-conservation activities by a more modest 7 percent. (Again, the researchers were able to determine this by using the girls in the residential-energy group as controls.)

These girls learned they could save energy by cutting back on meat and processed foods, by re-using their water bottles, by checking the tire pressure on their family cars and by walking or biking to school instead of driving.

But when they were surveyed again seven months later, the effect had worn off, the researchers found. Surveys of parents also showed that the lessons hadn’t rubbed off on them.

In hindsight, the researchers speculated that the Girl Scouts had less power to influence things like the amount of meat their families ate or the modes of transportation their families used.

Still, the GLEE interventions worked well enough for the researchers to recommend extending them to more Girl Scout troops, and perhaps to kids in other youth organizations as well. They noted that the course about household energy use prompted each Girl Scout family to cut its energy use enough to prevent the emission of 160 to 330 pounds of carbon dioxide per year, on average.

These results “suggest great potential to produce more widespread and far-reaching impacts,” the study authors wrote.

Alice Gronhoj, who studies environmental policy and the consumer behavior of children at Aarhus University in Denmark, agreed that the courses motivated families to conserve energy. But she added that more research is needed to understand which aspects of the GLEE curriculum were responsible for the changes in the girls’ behavior, and that of their parents.

No matter how much energy the Girl Scouts might save, policymakers had better not rely on them too much, Gronhoj wrote in an essay that accompanied the study.

“This should not distract us from the fact that the ultimate responsibility for reducing energy consumption and transforming a non-sustainable energy system rests with adults, and not with children,” she wrote.

——

©2016 Los Angeles Times