With the polar ice caps melting at alarming rates, temperatures rising worldwide and tropical storms becoming more violent, all signs point to global peril. Yet Earth's fate may depend on the globe atop your shoulders.

Psychologists are becoming increasingly aware of their role in curbing the devastating effects of global warming, and the best solution to climate change is behavior change, they say.

"With any problem of society that involves human behavior, such as global climate change, psychologists have a role to play in that," says APA President Alan E. Kazdin, PhD, of Yale University. Kazdin argues that if global warming is indeed due to human influence-as most scientists think-then changing human behavior is the most important step toward correcting the problem. "And that's wildly right in the middle of psychology," he says.

Kazdin chose to make Psychology's Contributions to the Grand Challenges of Society one of his priorities during his term as president. Effecting positive change in people's attitudes toward the natural world is a large part of this priority, he says. And it's also an opportunity for psychologists to showcase tangible effects of their skills, he adds.

"Let's show the public we can make a real contribution," Kazdin says. "We have the knowledge-there's no question about that-but we need to show we can get some things done."

Spreading the word

For starters, that means convincing people to reduce their energy consumption.

The American Geophysical Union, a scientific society composed of more than 50,000 earth scientists, teachers and students, issued a statement in January emphasizing that climate change is intimately tied to human energy use, and that successfully reducing our energy usage will depend upon the willingness of scientists, industries, governments and the public to work together.

According to the U.S. Environmental Protection Agency and the Department of Energy, if every household in the country replaced a single normal lightbulb with an energy-efficient compact fluorescent light bulb, it would reduce greenhouse gas emissions by an amount equivalent to that produced by 800,000 cars.

But convincing large numbers of people to act in concert is not easy. For one thing, there's a lot of confusion and misinformation out there, says Christie Manning, PhD, a visiting cognitive psychology professor at Macalester College in St. Paul, Minn., who also contributes to a Web site, www.teachgreenpsych.com, dedicated to helping instructors incorporate conservation topics in the classroom.

"People actually aren't aware of the extent to which their actions are contributing to environmental problems," she says. For example, people don't realize that eating a meat-heavy diet contributes more to climate change than not recycling, says Manning. And while recycling is well and good, she says, a more effective way to help the environment would be to eat less meat-a message that isn't as firmly entrenched in the public consciousness.

Responsibility for getting the word out about effective environmental solutions doesn't fall exclusively to psychologists, but they can and should do their part, says Britain Scott, PhD,a psychologist at the University of St. Thomas in St. Paul. Scott, who founded www.teachgreenpsych.com, advises academic psychologists to teach their students about the importance of sustainability.

"We have the opportunity-and the responsibility-to educate tomorrow's conservation scientists, policy-makers and grassroots activists about the fundamental connections between human behavior and the environmental crisis," she says. Scott's St. Thomas colleague Elise Amel, PhD, encourages psychologists to hold seminars for the public and for teachers in other disciplines to help them bring conservation into their classrooms, too.

Manning urges psychologists to reach out to their communities by helping local "green" organizations to fine tune their messages.

Peer pressure

But even when people do have all the right information, they still don't often act on it. "Information by itself is not enough," says Robert Cialdini, PhD. "You have to motivate people to use it."

Cialdini, an Arizona State University psychology professor who studies the science of persuasion, is putting his research to work for the planet. One of the most effective motivators he's found is a positive version of the classic adage "If everyone jumped off a bridge, would you?" By manipulating what people perceive as social norms, Cialdini says, you can achieve remarkable behavioral changes.

In a 2007 study, for example, Cialdini experimented with the wording on door-hanger notices encouraging people to conserve energy. One notice urged residents to think about their effect on the environment. Another informed them how much money they could save by using fans instead of their air conditioning. A third implored them to consider future generations. The fourth and final notice told residents that most of their neighbors actively conserved energy. Cialdini and his team distributed these door hangers randomly, then waited to see what, if any, the effects on energy conservation would be.

The first three notices-the appeals to the environment, money and future generations-all fell flat, achieving essentially no energy conservation. The final one, though, made a big difference. On average, those households dropped their energy usage by nearly two kilowatt-hours per day-a 10 percent reduction in daily power usage.

The study results reinforce mounting evidence for the theory that people, as social beings, rely far more on social cues than informational ones.

"There's an evolutionary explanation for it," Cialdini says. "The most primitive way we've developed to make decisions is to watch what other people in similar situations are doing."

These subtle cues can, of course, swing both ways. Well-intentioned environmental messages can have negative effects if they hype the idea that many people are contributing to the problem, he says. A public service announcement that proclaims, "So many people today are littering that the aluminum cans lying on our streets would stretch to the moon and back" would do more harm than good because it normalizes littering, Cialdini says. Instead, psychologists should make litterers feel as if they're in the minority, he advises.

Cialdini is publishing these findings not just in psychology journals, but in hotel-management publications, consumer research journals and popular magazines-for anyone who will listen, basically.

Overcoming obstacles

Psychologists can also address shortcomings where the potential for positive change exists but people, for whatever reason, are hesitant to embrace that potential. Raymond Nickerson, PhD, offers e-mail as an example of an environmental promise yet to deliver. Nickerson, a psychologist at Tufts University whose 2003 book "Psychology and Environmental Change" discusses these topics, says that despite the Internet Age's ability to reduce our paper consumption, people are still using just as much paper as ever-and possibly even more, according to some studies.

"This so-called 'paperless society' we've heard about hasn't really worked out," Nickerson says. "Ironically, it may have done the opposite. People prefer to read things on paper as opposed to a computer screen, and e-mail and the Internet have made it easier to just print it off."

Psychologists are investigating whether this is just a generational thing-Nickerson suspects younger people who've grown up reading on the computer might be less averse to electronic displays-or if the displays themselves are the problem.

This disconnect between innovation and environmental intention illustrates an important point: You can't predict exactly how people are going to use new technologies, Nickerson says. Just because an industry produces an environmentally friendly product doesn't mean that it will be used that way.

"If the technology gives you the promise but no one wants to use it, that's a tough obstacle," Nickerson says. "That's a psychological issue."

Like Cialdini, Nickerson believes psychologists play a big part in understanding why people might be averse to positive behaviors and that they can help cobble together strategies to make those behaviors more palatable.

Of course, psychologists can't do it alone. They, like the rest of the world, rely largely on the research of climate scientists, oceanographers, geologists and other physical scientists whose job it is to assess what behaviors are causing damage, and the risks associated with them. But Cialdini considers psychologists to be the arbiters of this information, charged with turning that research into action when it hits the public.

"We know how to most powerfully craft and transmit a message," he says. "We can be a lever for change."

A pivotal moment

These changes need to come quickly, though. Global warming is not something scientists can debate anymore, says psychologist Rep. Brian Baird, PhD (D-Wash.), who in January traveled to Antarctica, the Great Barrier Reef and an Australian rainforest to witness firsthand the effects of climate change. One disconcerting sight, Baird reports, was seeing the devastation to the expansive coral reefs off the northeast Australian coast. In response to rising ocean temperatures and increased ocean acidification, the reefs are losing the unicellular algae that they rely upon for photosynthesis. There's about a 50 percent probability that all of the world's coral reefs could die within 50 years, Baird says.

He likens the immobile coral's predicament to our own: The reef can't get up and move to a new climate, and we can't move off this planet. We have to live in the environment around us.

So if we're not going anywhere, we need to work to make here a better place. Changing public policy is one way to get people to be more environmentally conscientious, says Baird, who chairs the U.S. House of Representatives Subcommittee on Research and Science Education. Industry regulations and financial motivation will eventually have to reflect a greener outlook on production if we expect any lasting changes. But adjusting policy takes time and is largely dependent on the ebb and flow of politics-not really an option when catastrophic consequences loom low on the horizon.

To that end, the field of ecopsychology promotes a less egocentric mode of thinking in favor of a more eco-centric one. By encouraging humans to rethink their position in the natural world, some psychologists believe they can influence people to be more responsible stewards of nature.

"Attitudes toward nature are very important," Nickerson says.

For instance, hikers and snowmobilers both use mountains recreationally, but hiking is generally less damaging to the ecosystem, he says. A hobby like hiking, ecopsychologists say, fosters a positive, self-inclusive attitude toward nature that reflects in other behaviors, as well. It's one more tool psychologists can use to promote environmental responsibility.

Baird recognizes that behavioral and attitudinal change is ultimately what's going to make or break the planet, and that's where psychologists need to step up their game.

"If psychologists just spend their time talking to each other about esoteric topics," says Baird, "they'll have no impact whatsoever. But if they realize they need to be active in their own communities, go to town hall meetings, craft a strategy and become activists, then they can make a difference."

Kazdin agrees, saying APA can serve as a sort of clearinghouse for pro-environmental psychological approaches. Members can talk with staff of APA's directorates and devise a plan for how their individual talents map onto the overarching goals of conservation and sustainability. Kazdin believes APA's depth of experience and diversity makes it a natural choice for coordinating joint research projects between different fields and then disseminating information.

"By mobilizing our own group and bringing in diverse people, we can provide a science-based technology for effecting change," he says.