How Behavioral Science Supports Climate Action: Interventions That Turn Intent Into Measurable Change

Last updated October 23, 2026

In a survey of nearly 130,000 people in 125 countries, published in Nature Climate Change by Peter Andre, Teodora Boneva, Felix Chopra and Armin Falk, about 7 in 10 people said they would give 1% of their household income each month to fight climate change. The same respondents guessed, on average, that only about 4 in 10 of their fellow citizens would do the same.

Behavioral science supports climate action by finding out why people and organizations fail to follow through on sustainable intentions, then redesigning the decision environment through defaults, social norms, incentives, well-timed prompts and easier choices. The most effective programs measure real behavior, such as energy use, travel, purchasing or waste, rather than relying on attitudes alone.

At The Decision Lab, our climate and sustainability work ranges from helping the City of Rome prepare residents for a diesel vehicle ban to moving customers of one of the world's largest coffee chains toward reusable cups. In each project we start from the specific decision people face, and we judge the work by what people do afterward.

The Intergovernmental Panel on Climate Change estimates that demand-side measures, meaning changes in how people use energy, travel, eat and build, could cut greenhouse gas emissions in sectors such as buildings and land transport by between 40% and 70% by 2050, compared with baseline projections. That estimate covers new technology and infrastructure as well as everyday habits, but each piece still depends on people and organizations choosing to adopt it.

For most climate programs, public goodwill is already in place, and what fails is the step between a favorable attitude and a repeated action. In our work, and in the research we draw on, that step breaks for five recurring reasons.

1. Misread social norms. People underestimate how many others care, and many will only act when they believe others are acting too. Andre and colleagues found that in 110 of the 125 countries, most people believed they were in the minority, even though a majority were willing to act.
2. Extra effort. When the greener choice requires opting in or carrying something extra, a small cost today wins over a large shared benefit later.
3. Habit. Commuting and thermostat settings run on routine, and routines respond poorly to new information.
4. Distance. Emissions figures feel abstract and far off, so they rarely compete with values people already hold about their family or their city.
5. Incentives that point the other way. In an office, employees rarely see the energy bill, so the saving that motivates households is invisible at work. In agriculture, the rewards farmers face may not match the practices a program wants.

Behavioral science supports climate action in two ways. It designs programs that change specific behaviors directly, such as home energy use or how people commute. It also helps climate policies and infrastructure work as intended, by dealing with the decision barriers that stop people from accepting or using them. In both cases it adds to policy and infrastructure rather than replacing them.

Behavioral interventions work best when they target a specific barrier and sit alongside the policy and infrastructure a program needs. Defaults can raise uptake of renewable energy, but they cannot make clean energy affordable. Messaging can build acceptance of a transport policy, but it cannot stand in for public transit that people can actually use.

Rome shows what happens when the behavioral side is skipped. Before its diesel ban, the city restricted diesel cars to alternate days based on whether their license plates ended in odd or even numbers, and many families responded by buying a second car. When the city later decided on a full ban in its historic center, it brought us in to help residents accept the change before it took effect.

The behavioral interventions with the strongest field evidence for sustainable behavior are social comparisons, financial incentives, defaults and prompts timed to moments when routines change. Information and education campaigns tend to change behavior the least. Average effects are modest, so programs should focus on the behaviors and groups where a small shift adds up to a large saving.

The most complete summary of the field comes from Magnus Bergquist, Maximilian Thiel, Matthew Goldberg and Sander van der Linden, who combined 10 earlier meta-analyses covering 430 field studies in a second-order meta-analysis of climate mitigation interventions in the Proceedings of the National Academy of Sciences. Interventions built on social comparison or financial incentives changed behavior the most, and education and feedback changed it the least. Energy conservation behaviors also moved more easily than transportation behaviors such as driving less.

The same review is a useful check on expectations. Once the authors corrected for the tendency of journals to publish successful studies, the average effect came to a shift of roughly 2 to 7 percentage points in the targeted behavior compared with control groups, depending on the correction used. The authors suggest one reason large programs show smaller effects: they often reach people who never signed up, while small studies often work with volunteers.

Hunt Allcott studied home energy reports that compare each household with its neighbors, sent by the company Opower to about 600,000 US households that were randomly assigned to receive the reports or not. Households that received them cut energy use by 2% on average compared with those that did not, about the same effect as a short-run electricity price rise of 11% to 20%. The highest-using tenth of households cut their use by 6.3%, while the lowest-using tenth cut theirs by 0.3%.

Felix Ebeling and Sebastian Lotz ran a randomized trial of green energy defaults with about 42,000 German households shopping for an energy contract. When the more expensive green tariff was pre-selected, so customers had to untick it to refuse it, households were nearly ten times as likely to buy it as when they had to tick it themselves. Support for the Green party predicted green purchases only when there was no default.

Bas Verplanken and Deborah Roy gave a sustainability intervention to 800 people in a field experiment on habits and moving house, half of whom had recently relocated. The intervention changed behavior more among recent movers than among matched households who had not moved, and that window lasted about three months after the move.

In our own program design, this evidence pushes us toward defaults and social comparisons, timed to moments when routines are already changing, before we consider an awareness campaign.

Organizations change employee sustainability behavior by choosing behaviors employees can control and making the sustainable option the default in company systems. Visible ownership of shared spaces and feedback at team level keep the change going, and the program should be judged in operational units such as kilowatt-hours or travel emissions rather than by staff surveys.

Employees face a version of every barrier above, plus one more: at work, the person acting is rarely the person paying. Russell and colleagues co-designed a workplace energy conservation program with one organization, combining visible commitment from top management with prompts to save energy. Over six months, both observed and self-reported energy-saving behavior improved, and the program worked best for behaviors that employees were individually responsible for.

In our organizational behavior work, we build workplace sustainability programs around six practices.

1. Choose a behavior employees can control. Good starting points include shutting down equipment, booking travel, choosing suppliers and printing, because each one sits with an individual rather than a facilities team.
2. Make sustainable behavior the organizational default. Travel platforms, purchasing systems, printer settings, equipment sleep modes, catering rules and building controls can all present the sustainable option first, so employees opt out rather than in.
3. Create visible ownership. Shared equipment and common spaces drift because no one person is responsible for them, so name an owner for each shared space or operational target.
4. Use team-level feedback. Social comparison was among the strongest levers in the Bergquist review, and comparing departments or sites gives employees a reference point without publicly singling anyone out.
5. Time interventions around routine changes. Research on household moves shows that disrupted routines can create a temporary opening for behavior change. Organizations can test whether comparable moments, such as new-hire onboarding, office moves, procurement-system changes or shifts to hybrid work, create the same opportunity.
6. Measure behavior and operational impact. Tie the program to kilowatt-hours, contamination in waste streams, travel emissions, purchase compliance or reuse rates, and set a baseline before anything changes.

These practices also need a way to spread beyond the first pilot. For one global coffee chain, we built a Behavior Change Blueprint, an interactive framework that anyone in the company could click through to see the drivers of and barriers to reusable cup use, so that teams beyond the sustainability function could design their own interventions after the project ended.

Energy use

Home energy reports and green defaults are the best-tested tools in the field. For utilities and public agencies, we focus early on which households to reach, since Allcott's data show savings concentrated among the heaviest users.

Transportation

Travel behavior is harder to shift than energy use, so programs work best when paired with a change in infrastructure or rules. The behavioral work then goes into how the change is framed and when it arrives, as in Rome, where we recommended describing the policy as a gradual transition away from diesel rather than an abrupt ban.

Recycling and waste

Reuse and recycling programs often fail at the point of purchase or disposal, where convenience wins. The levers that apply are defaults at the counter and visible norms about what other customers do.

Procurement

Organizational purchasing is a chain of defaults: approved supplier lists, standard specifications, pre-filled order forms and travel booking settings. Changing what appears first, and what needs a justification to override, applies the logic of the Ebeling and Lotz trial to an organization's own buying.

Climate resilience

Preparedness behaviors, such as signing up for heat or flood alerts or checking insurance coverage, face the same gap between concern and action. Here we apply the same principles: make enrollment the default where rules allow, and time outreach to moments when routines are already changing, such as a move.

We report each of our climate projects in the same format, so readers can see what was measured and what the result does and does not prove.

Public policy and mobility: the City of Rome

• Client context: the City of Rome's diesel vehicle ban for its historic center, set to start in 2024, after earlier restrictions had been worked around.
• Behavior targeted: residents' acceptance of the ban and their compliance with it.
• Barrier identified: air-quality statistics felt abstract, and past rules had prompted workarounds.
• Intervention designed: a messaging strategy that tied the transition to values residents already held, including family and the city's history, and framed it as a gradual shift away from diesel.
• What was measured: the published case study reports the strategy's reach, more than 3 million residents.
• What the result does and does not prove: it documents how we diagnosed and designed for public acceptance, but it does not report a measured change in compliance.

Consumer reuse and waste: a global coffee chain

• Client context: one of the world's largest coffee chains wanted customers to switch from disposable to reusable cups in its cafés and its mobile ordering app.
• Behavior targeted: choosing a reusable cup.
• Barrier identified: customers' reasons varied, from the hassle of carrying a mug to feeling out of place as the only person using one.
• Intervention designed: a review of more than 100 papers and three workshops with the client produced more than 115 possible behavioral levers, narrowed to 39 interventions ranked on criteria including projected cost and estimated impact, plus the Behavior Change Blueprint described above.
• What was measured: the client reports hundreds of thousands of cups diverted from landfill in pilots that included some of the playbook's interventions.
• What the result does and does not prove: the interventions reached real rollouts, but the figures are client-reported, come without a controlled comparison, and cannot be attributed to individual interventions.

Climate-smart agriculture: Solidaridad

• Client context: Solidaridad's programs to encourage climate-smart farming in the municipalities where it works in the Brazilian Amazon.
• Behavior targeted: farmers' adoption of climate-smart practices.
• Barrier identified: incentives did not match the practices the program wanted. Social norms also carried less weight than in Solidaridad's earlier South African work, because Brazilian farmers often lived far apart and talked mostly over WhatsApp instead of meeting at the market.
• Intervention designed: a structured method for building incentive frameworks for any population, applied through face-to-face interviews that senior Solidaridad staff ran with farmers, and a behavior change framework built from the results.
• What was measured: the published case study describes the method and framework and reports no adoption figures.
• What the result does and does not prove: it shows why a lever that worked in one country cannot be assumed to transfer to another, but not how much adoption the framework produced.

Corporate sustainability communication: carbon pricing research

• Client context: our own research on how consumers judge corporate sustainability initiatives under Canadian carbon pricing.
• Behavior targeted: consumers' willingness to do business with a company.
• Barrier identified: it was unclear whether framing a company's clean-energy investment as its own choice, rather than as compliance with regulation, would change how consumers saw it.
• Intervention designed: an online experiment with 118 Canadians, who saw the same information about companies investing in sustainable energy under one of the two framings.
• What was measured: consumers were significantly more willing to do business with companies framed as green, and described them more favorably.
• What the result does and does not prove: framing changed stated willingness in a small online sample, but the study did not measure actual purchases.

Our behavioral design process has five steps, and the first two take more time than most clients expect.

1. Define the behavior precisely. "Reduce emissions" is a goal. "Facilities managers lower office heating on weekends" is a behavior someone can do and someone else can measure.
2. Diagnose barriers with the people who face them. Our Solidaridad work showed that a lever copied from another country can turn out to be much weaker where it is applied.
3. Design against the barrier. A default answers an effort barrier, a norm message answers a misread norm, a values-based frame answers a distant issue, and a change of incentive answers rewards that point the wrong way.
4. Test before scaling. A randomized controlled trial is the strongest evidence, but it is not always possible or necessary. When a city policy applies to everyone at once, a staggered rollout or a matched comparison area can still show whether behavior moved.
5. Hand over the tools. Clients keep the playbooks and measurement plans, so their teams can extend the work after we leave.

A climate behavior program should report what people did, in units that connect to emissions or waste: kilowatt-hours used, car trips taken, contamination in recycling streams, or the share of purchases that meet a sustainability standard. Attitude and awareness surveys can help explain a result, but they are a poor stand-in for the result itself.

Two further checks matter. The first is persistence. In Allcott's early Opower pilot in Minnesota, households that received reports every quarter saved less in the months between letters and saved more again when the next letter arrived, so the timing of reminders shaped the result. The second is distribution. An average can hide large differences between groups, as the gap between the heaviest and lightest Opower users showed, and those differences decide where a program should spend its budget.

How can behavioral science support climate action?

Behavioral science helps at the moment people decide, such as signing an energy contract or choosing a commute. One low-cost starting point is correcting misread norms: Andre and colleagues suggest that telling people how many fellow citizens are willing to act could raise willingness further. Programs should then test whether behavior changes, since opinion can shift without it.

What are examples of behavioral interventions for sustainable behavior?

Examples include energy reports comparing a household's use with its neighbors', renewable energy tariffs set as the default, reusable-cup prompts at the point of ordering, peer comparisons between office teams, and sustainability programs delivered to people who have just moved house. Each targets a specific barrier, so the right choice depends on what is holding people back.

Which sustainability behaviors should organizations target first?

Start with behaviors that employees control individually and that already show up in company data, such as travel bookings or purchasing. Within those, prioritize the behaviors with the most emissions or cost at stake. Shared spaces and shared equipment usually need a named owner before any behavioral program can work there.

Do nudges work for climate change?

Yes, with realistic expectations. Across 430 field studies, average effects were modest once publication bias was accounted for, a shift of roughly 2 to 7 percentage points. Some single tools are much stronger: a green energy default made German households nearly ten times as likely to choose renewable power. Nudges work best alongside prices and regulation.

What is the intention-behavior gap in sustainability?

The intention-behavior gap is the distance between what people say they will do for the environment and what they actually do. It usually comes from the situation people are in, since effort and habit stop many people who mean well. Programs that measure only stated intentions will overestimate their own impact.

How do you get employees to adopt sustainable behaviors at work?

Visible commitment from senior leaders matters: in Russell and colleagues' workplace study, it was a core part of the program that changed energy-saving behavior. Pair it with prompts where the behavior happens and defaults in shared systems, and launch changes when routines are already shifting, such as during an office move.

How do you measure the impact of a sustainability behavior change program?

Measure the behavior itself in units tied to emissions or waste, such as kilowatt-hours or car trips, against a baseline and ideally a comparison group. Track results for months rather than weeks, because effects can fade between reminders. Report results by segment, since the heaviest users often account for most of the savings.

Should behavioral programs replace carbon pricing or regulation?

No. Behavioral programs help prices and rules work and fill gaps neither reaches. Allcott found that neighbor-comparison energy reports cut household use about as much as a short-run electricity price rise of 11% to 20%, and compared favorably on cost with traditional conservation programs. In Rome, behavioral messaging supported a ban the city had already chosen.

• Reducing Smog in the Eternal City: behavioral messaging for Rome's diesel ban
• Brewing Better Habits: nudging coffee customers toward reusable cups
• A Blueprint for Climate-Smart Farming with Solidaridad
• Consumer perception of corporate sustainable practice initiatives

If your organization is planning a climate or sustainability program and wants to know which behavior to target first, talk to our behavioral science team about a diagnostic.