How to make climate transitions stick

During the COVID-19 pandemic, air travel declined dramatically. Many view the disruption as a potential tipping point for reducing emissions from the aviation sector. However, once travel restrictions were lifted, passenger traffic quickly rebounded to pre-pandemic levels and, in many regions, even surpassed them. As flying restrictions did not translate into a shift in social norms in which society acquired new values, or long-term incentives, aviation demand returned. In the COVID-19 case, the significant change in behavior did not lead to a lasting transition.

A study led by Claudia R. Binder, professor at the Laboratory on Human-Environment Relations in Urban Systems (HERUS), suggests that long-term climate action success depends on creating a stable transition through supportive policies, infrastructure, and social acceptance. "In a transition toward net-zero emissions, we want people to adopt and maintain more sustainable behaviors," says Binder. Published in PLOS Climate, the interdisciplinary study combines ideas from ecology with evidence from real-world climate transitions to identify policies that can help sustainable changes endure over time.

Pully as a laboratory for climate transitions

A social tipping point occurs when enough people adopt a new behavior or technology so that it starts spreading rapidly through society. While many studies focus on how to reach these tipping points, much less attention has been paid to how the resulting changes can be maintained over the long term.

In natural ecosystems, these tipping points occur frequently. For example, a coral reef can reach a tipping point when ocean temperatures become too high and many corals die. Once a certain number of corals is lost, algae take over the reef, and fish and other marine life begin to disappear.The reef can then become stuck in this damaged state, even if conditions later improve.

For their study, Binder and her team worked with the municipality of Pully. In collaboration with the sustainability team, the researchers analyzed how different technological, behavioral, and policy factors interact within the local energy system.

They focus on the adoption of solar technologies. Following a qualitative approach, they found that before solar technologies become widely adopted, factors such as costs, financial incentives, and technology availability play the dominant role. After the tipping point, however, cultural and societal interactions appear to become increasingly important. As more people install solar systems, for instance, they make the technology visible to others, helping to establish new social norms and increase public confidence in renewable energy. “If all my neighbors are installing photovoltaics, I'm more likely to do it than if they don't,” says Binder. Conversely, without complementary technologies like electric vehicles or heat pumps, solar adopters may be more likely to revert when circumstances change.

The findings from Pully point out that, while technology and incentives can help initiate change, the adoption of sustainable technologies over time depends on establishing social norms and community networks. “While the strength of these effects may vary from one municipality to another, the underlying mechanisms are likely to be relevant to other municipalities beyond Pully,” says the professor.

Beyond tipping points

The recommendations address both objectives: accelerating the transition and stabilizing it once it takes place. According to the study, effective policy initiatives should combine a long-term vision, including efforts to shape social norms and public perceptions, with short-term incentives such as subsidies and financial support.

The study suggests that infrastructure investments can support long-term adoption of sustainable technologies. For example, expanding electric vehicle charging networks makes electric cars a more practical long-term choice. Policies that encourage to adopt complementary technologies can further reinforce and lock-in change, such as pairing rooftop solar panels with home batteries or electric vehicles.

Governments and organizations can also work with early adopters of sustainable technologies to showcase them and help bridge the gap between adopters and non-adopters.

A shift in thinking

These questions build on the team's broader interest. Binder and her team are now exploring how urban infrastructures, such as those related to mobility, housing, and local services, can shape sustainable behaviors. The question is whether designing neighborhoods around accessible facilities can make low-carbon lifestyles the easier choice. “If people live very close to public transport, have a gym nearby, and have places to meet friends just around the corner, will this lead them to stop using their car?” Binder asks.

Further research aims to quantify both the costs and benefits of such investments. For example, the researchers want to estimate how much carbon, materials, and resources are required to build these infrastructures and assess the extent to which this can change behavior without compromising their perceived well-being. The goal is to understand how cities can create environments that naturally support more sustainable choices. As Binder puts it, quoting Einstein, “Solving today's interconnected environmental challenges might require a shift in thinking rather than simply more of the same.”