Swedish climate activist Greta Thunberg has scolded world leaders for failing to save her generation from climate change, rallying youth climate strikes and taking millions of people to the streets worldwide, demanding action. For many, Thunberg’s emotional oratory is a spark.
To us, however, Thunberg’s environmental actions are more impressive than her words. Thunberg crossed the Atlantic Ocean aboard a zero-emission sailboat to attend September’s climate talks in New York, eating freeze-dried food, not showering, and eschewing other comforts of air travel to spend 15 days on the high seas.
Thunberg’s sacrifice epitomizes the challenge underlying climate change: if global warming is to be curbed, comfortable lifestyles in developed countries must be amended. Put another way, it doesn’t matter how much uproar an activist’s speech creates because it distracts from the fundamental fact that the only way to save our planet is to change how we live.
Policy makers have long struggled with how to encourage uptake of more eco-friendly behaviors, such as eating fewer animal products, reducing air-conditioning use, flying less and taking more public transportation. A die-hard assumption is that when people are presented with information about how to curb climate change—for instance, via energy labels (Energy Star), public-service announcements or media messaging (“Save Water, Take Shorter Showers”)—they will adopt greener habits.
But our research, which was recently published in Nature Communications, throws ice water on a theory that was already frosty. People do not change their environmental behaviors simply because they are told to. Rather, they must be enticed to make greener lifestyle choices with interventions sufficiently compelling to overcome the strong resistance to changing habitual, comfy habits. Identifying these motivators, and the psychology behind them, could help slow the climate-change crisis.
To understand how interventions affect environmental behaviors, we looked at more than three million observations of peoples’ habits from 83 field experiments conducted between 1976 and 2017 in more than 20 countries. Our focus was not to gauge the climate benefits of a given mitigation strategy; we only examined how policies influence behaviors.
What we found will be surprising to most policy makers, practitioners and environmental advocates. While the majority of the world’s climate-mitigation efforts appear to be information-based interventions, these campaigns rarely produce impactful behavioral changes. Information designed to influence lifestyle choices—such as whether we buy energy-efficient appliances, or turn off the water when we brush our teeth, or even how many towels we use at hotels—is not an effective climate solution.
Behavioral interventions work best when people are exposed to strong competing motivations. One example is social comparison, the idea that people will change behaviors when they realize they are doing less for the environment than their peers or neighbors. But interventions are most impactful when subtle contextual changes rearrange the physical context in which people make choices. These changes, also known as “nudges,” pave the path of least resistance, making the pro-environmental choice the convenient and easy one.
For example, when recycling bins are located on every floor of a building, rather than only at the entrance, people are more apt to recycle because they have less distance to walk. Similarly, when hotels automatically set air conditioning to sustainable temperatures (77 degrees Fahrenheit) they save energy because guests tend not to adjust the thermostat.
Given these insights, how should the world respond?
Policy makers can lead by recognizing that people will not easily alter their high-carbon habits; they must be nudged. Just because someone believes in climate change or expresses support for carbon neutrality does not mean they will trade in their SUV for a bus pass. Information without motivation is useless. To halt global warming, leaders must ditch the decades-old strategy of providing information and hoping that people will make the “green” choices themselves.
When applied strategically, behavioral nudges could become powerful policy tools in the climate-change fight. If, for instance, utility companies implemented a default choice for renewables (opt-out), customers could lower their carbon footprints without doing anything. Supermarkets could reduce the consumption of animal products by designing stores that displayed meat and dairy in less accessible areas. And if cities did more to promote bicycling—with more bike lanes than car lanes, for example—vehicle use could naturally fall. These strategies may be especially relevant at the state and local level, where the bulk of climate action in the U.S. is now focused.
Consumers also have a role to play. If people are serious about saving the planet, they must stop hiding behind false hopelessness and realize that corporations respond to consumers’ demands. At the moment, that message is not being delivered. For instance, while “flight shaming” has won favor as a way to reduce carbon dioxide emissions, too few travelers are opting to stay on the tarmac. One recent poll found that only 14 percent of people surveyed would stop flying if the alternative was less convenient or more expensive. In other words, voluntary sacrifice is not a widespread virtue.
Climate change is at hand, and within a decade, warming trends could become irreversible. And yet, even as concern for climate change grows, ecological behaviors are stuck in slo-mo. Blaming the industry and policy makers for limited action is an attribution error.
Perhaps that’s what draws us to activists like Thunberg. Against the odds and contrary to most peoples’ habits, her climate actions match her climate words. Thunberg doesn’t seem to need nudges, social influences or taxes, which, as our research shows, is a rare quality. But our findings also suggest that with some restructuring of social environments, possibly combined with incentives and regulations, it’s possible to push more people to follow in her concrete ecological footsteps. Best of all, when nudges are well designed, the sacrifices will become second nature.