What unsustainable behaviour needs to change:

Speeding trucks on unpaved construction roads stir up large amounts of dust, posing serious health risks. Truck movement can contribute up to 50% of PM10 emissions—fine dust particles small enough to enter the lungs— on-site (Giunta et al. 2019). Yet on many sites, speed limits are ignored due to weak enforcement and low awareness.

At the Gurugram (part of the National Capital Region) pilot site—an active Indian construction zone grappling with air quality concerns—only 16% of heavy-duty vehicle drivers followed the 10 km/h speed limit. With no reminders from guards, dust control wasn’t seen as a priority.

The Green Nudge:

To reduce dust, a simple strategy was introduced: guards were trained to verbally remind incoming truck drivers about the 10 km/h speed limit and explain its role in improving air quality. Posters reinforced the message visually, and drivers were invited to voluntarily commit to following the rules.

Why did it work? People are more likely to comply when reminded by someone credible,when they actively commit to a behaviour, and when consequences are made concrete. Guards fit this role perfectly, reinforcing site rules with authority and clarity. This approach combined salient cues, social reinforcement, and personal accountability.

The results: This low-cost nudge raised compliance from 16% to 63%. As trucks slowed down, dust pollution dropped–PM10 by 11%, PM2.5 by 29%—regardless of weather conditions.

The business case: Less dust means healthier workers, fewer sick days, and stronger regulatory compliance—all achieved with minimal investment and no new infrastructure required.

Do you know of any other nudges that reduce construction site pollution and thus cut health costs?
Feel free to get in touch: hello@green-nudges.com

From the Clean Air team at the Council on Energy, Environment and Water (CEEW), Delhi: Arvind Kumar (behavioural science), Dr. Mohammed Sahbaz Ahmed (air quality modelling), Dr. Arpan Patra (urban pollution compliance), Sandeep Narang (sustainable construction), and Dr. Abhishek Kar (Senior Programme Lead). The team combines behavioural science, air quality modelling, and on-ground interventions to tackle urban air pollution—from construction dust to transportation emissions.

What unsustainable behaviour needs to change:

It’s Friday afternoon. You’re tired after a long week, rushing through the supermarket on autopilot. You have good intentions — to eat healthier, shop more sustainably — but in the moment, those values are quickly overridden by fatigue, convenience, and price cues.

Sound familiar? This everyday scenario reveals why good intentions often fall short in the grocery store. Despite growing climate awareness, most of us still grab the convenient, familiar choices. The problem isn’t that we don’t care—it’s how our brains respond under pressure.

Here’s why:

• Mental shortcuts under pressure (decision fatigue): When we’re tired and rushed, our brains default to familiar patterns
• Too much information (cognitive overload): With thousands of products competing for your attention, we can’t process what’s truly sustainable
• Bold price tags win (price salience bias): Eye-catching sale stickers trigger our deal-seeking instinct, regardless of actual value

Traditional campaigns often miss the mark on promoting more sustainable choices because they expect people to be deliberate. But most shopping is reactive– shaped by fast, unconscious judgments, not slow, rational decisions.

The Green Nudge:

In a study with a Danish supermarket, Krukow Behaviour Change tested a remarkably simple intervention:

• Yellow dot stickers were added to healthy, everyday vegetables like cabbage, potatoes, and broccoli.
• The dots mimicked „sale“ tags, using price cues to trigger the brain’s deal-seeking instinct — but without changing the price.
• These items were placed in high-traffic areas, making them easy to grab without extra effort.

The results: Shoppers who encountered the yellow dots were 46% more likely to choose the healthier option.

No discounts. No education campaign. No added friction. Just a subtle visual cue that leveraged our brain’s automatic assumption that visually prominent items offer special value (price bargain heuristic).

The intervention cost virtually nothing to implement and required no staff training or system changes. This shows how design tweaks—not big budgets or awareness campaigns—can shift real-world behavior.

The Business Case: The yellow dot acts as an evolutionary nudge that drives purchase behaviour through instinctive attention cues — raising sales without eroding margins or requiring promotion spend.

What other clever in-store nudges have you spotted that actually work?
Feel free to get in touch: hello@green-nudges.com

From Sille Krukow, a global leader in Behaviour Design with over two decades of experience helping organizations like Procter & Gamble, Electrolux, and the European Commission turn behavioral insights into measurable sustainability outcomes. She’s a frequent keynote speaker and guest lecturer whose design based methodology shows how small environmental cues can drive big shifts in decision making. 

What unsustainable behaviour needs to change:

Urban noise pollution–although often overlooked—is a silent threat. Excessive honking in congested cities like Mumbai can reach over 100 decibels, well above the WHO’s safe threshold of 85 dB.

Prolonged exposure contributes to stress, cardiovascular strain, hearing loss, and a lower quality of life—particularly for children, the elderly, and shift workers living near busy intersections.

Yet honking persists due to impatience, social norms, and the illusion of control at red lights. Traditional fines don’t scale, and awareness campaigns rarely shift deep-seated habits.

The Green Nudge:

To reshape this noisy norm, Mumbai Traffic Police, in collaboration with FCB Interface, launched a pilot campaign in late 2019 called the „Punishing Signal.“ At five busy intersections—including CSMT and Marine Drive—traffic lights were fitted with decibel meters and LED displays. If honking exceeded 85 decibels, the traffic light’s countdown timer reset, extending the red light duration.

The display delivered a cheeky but clear message: “Honk More, Wait More.”

This intervention flipped the script. Honking—usually seen as a way to assert urgency—suddenly became counterproductive. The campaign applied negative reinforcement, where the removal of an unpleasant experience (waiting) depended on a desired behaviour (staying quiet). Rather than moralising, the nudge aligned with drivers’ real-time emotions—turning impatience into a self-imposed delay.

The results

• 32 % reduction in average honking decibels one month post-pilot (Source: Ad Age)
• Widespread awareness: social media video generated 3.6 million views, 22,000+ likes, and 9,000+ retweets
• International acclaim for combining humour, salience, and enforcement—without compromising driver autonomy

By turning honking into a self-imposed penalty, Mumbai reframed impatience as an incentive to stay quiet—reducing noise pollution by nearly a third. The campaign’s traction and acclaim hint at its potential to influence public norms in other cities. 

Do you know of any clever nudges that help cut noise pollution in cities?
Feel free to get in touch: hello@green-nudges.com

From Laura Sommer PhD from the Green Nudges Consulting team. This edition explores how urban frustration was turned into a force for collective calm by Mumbai Traffic Police and FCB Interface.

What unsustainable behaviour needs to change:

The World Economic Forum’s Global Risks Report 2025 ranks misinformation as the most pressing short-term global risk. Coordinated climate mis- and disinformation is among the most damaging of forms–eroding trust, fuelling division, and delaying essential climate action.

This is not simply a failure of awareness, but a result of manipulative content designed to bypass critical thinking. Emotional language, conspiracy cues, and divisive dichotomies exploit our cognitive shortcuts—making people more likely to dismiss climate science or reject effective policies.

In a world where public consensus is vital for large-scale action, the spread of false information undermines both civic engagement and sustainable behaviour change.

The Green Nudge:

Psychological inoculation—offering a “mental vaccine” against misinformation—is proving effective in building resistance. Roozenbeek et al. (2022) tested this through “prebunking” interventions that mirror vaccine logic: exposing people to a weakened dose of misinformation, paired with a clear breakdown of the manipulative tactic behind it.

In collaboration with YouTube, short ads warned viewers about common manipulation tactics, such as emotional language and scapegoating,explained simply and reinforced with humour. The aim was to help people recognise these tricks and learn how to resist them. For example, Cambridge’s ‘Emotional Language’ prebunking video shows how alarmist words like ‘hoax’ and ‘scam’ fuel doubt about climate science– and how learning to spot these cues makes them far less persuasive.

The results: Within 24 hours, participants were significantly better at spotting misleading headlines using the tactics they had just learned. Across studies, the approach improved critical judgement and reduced willingness to share false content. These effects held up across political affiliations and demographic groups—crucial in today’s fragmented media landscape.

Implications for Communication Campaigns:
For communicators, these findings offer a practical and scalable intervention:

• Prebunking content can be integrated into social media, news platforms, or public service ads.
• Humour and storytelling improve recall, making “cognitive antibodies” stick.
• Campaigns should name the tactic, not just refute the claim (e.g. “This uses fear to manipulate you”).
• Prebunking is more effective before exposure to misinformation than reactive debunking.
• This approach supports media literacy without needing to change minds through argument—making it well-suited for polarised audiences.

Have you used similar techniques or considerations in your own communication campaigns? 
Feel free to comment or get in touch: hello@green-nudges.com

From Nanon Wollenhaupt, an applied behavioural scientist who designs evidence-based interventions for public good. Her work focuses on communication strategies and behavioural change in mental health and sustainability.

What unsustainable behaviour needs to change:

Every summer, UK music festivals generate a tidal wave of waste—an estimated 250,000 tents are left behind after just one use. Often made from non-recyclable, fossil-fuel-based materials like polyester and nylon, each tent equals the plastic content of about 200 bottles or 9,000 straws.

Despite awareness campaigns and environmental concern, this wasteful habit lingers. Why? Behavioural barriers stand in the way:

• Present bias: When tired festival-goers head home, packing up a tent feels like too much effort.
• Diffusion of responsibility: Seeing others leave their tents makes it feel acceptable to do the same.
• Perceived disposability: Cheap, easy tents marketed for single use reinforce throwaway culture.

The result? Mountains of tents destined for landfill or incineration—despite good intentions.

The Green Nudge:

Decathlon’s No Tent Left Behind campaign is a smart nudge towards circularity. Here’s how it works:

• Purchase: Buy any Decathlon tent between 9 June and 14 September 2025.
• Return: Bring it back used or unused to any Decathlon store, with proof of purchase, before 14 September.
• Reward: As a free Decathlon Member, receive a gift card for the full purchase value.
• Reuse: Returned tents are refurbished for resale through Decathlon’s Second Life programme or dismantled and recycled.

The scheme removes friction and reframes the end-of-use moment as a win-win—rewarding responsible behaviour rather than relying on guilt. It works by:

• Framing the return as a reward instead of a loss.
• Simplifying the process with clear steps and no hidden costs.
• Normalising reuse through visible reminders at festivals—look out for flags reading “I’m not leaving my tent behind. You shouldn’t either.”

By embedding circular design into the experience, Decathlon shows how businesses can lead on sustainability—making it easy to do the right thing, not harder.

Are you aware of any other nudges that help cut wasteful habits at events?
Feel free to comment or get in touch: hello@green-nudges.com

From Tessa Clarke, co-founder and CEO of Olio, the award-winning app tackling household and community waste. Tessa grew up on a farm where wasting food was unthinkable—a mindset shaped by her mother’s mantra: “Waste not, want not.” After more than 15 years in the corporate world, where waste was rife, she set out to become part of the solution. Through Olio, she’s built a global community of over 8 million users who have shared more than 100 million meals and 14 million household items—proving that systemic change starts with local action.

What unsustainable behaviour needs to change:

In densely built cities like New York, dark rooftops absorb and trap heat, intensifying the urban heat island effect. During summer, rooftop temperatures can reach up to 190°F (88°C), which is7 to10 °C higher than surrounding green spaces.

This raises indoor temperatures, strains cooling systems, and increases health risks–especially for vulnerable residents. Despite clear environmental and economic costs such as higher emissions and electricity bills, most building owners don’t take action.

Barriers include perceived complexity, upfront effort, and behavioural biases like default thinking (“my roof’s always been like this”), the invisibility of energy waste, and a tendency to underestimate long-term benefits.

The Green Nudge:

NYC °CoolRoofs makes climate action easy, social, and visible—three key ingredients for changing behaviour. Instead of relying on people to seek out solutions, the programme removes effort: building owners simply sign up online, and the city provides everything—paint, gear, and labour. This reduces friction and helps overcome the status quo bias.

The initiative is also deeply social. Volunteers, students, and community groups work together to paint roofs, creating a sense of shared purpose. This taps into social norms:we’re most likely to act when we see others doing it too.

To reinforce impact, participating buildings get a °CoolRoofs placard and are shown on public maps—offering recognition and encouraging others to follow. Before-and-after thermal images make energy savings visible, building trust and motivation.

The results:

• Since its inception in 2009, NYC °CoolRoofs has coated over 12 million square feet of rooftop surfaces across more than 600 buildings.

• The reflective coating can lower rooftop temperatures by up to 43°F (24°C) and reduce indoor temperatures by as much as 30%, leading to significant energy savings.

• For every 2,500 square feet of coated rooftop, the city’s carbon footprint shrinks by approximately one ton of CO₂ annually.

• Beyond environmental impact, the program doubles  as a workforce development initiative– providing paid training and hands-on work experience in the construction sector to job-seeking New Yorkers.

By combining smart timing, easy steps, and visible social proof, °CoolRoofs nudges people from good intentions to real action.

Do you know clever nudges that help cities stay cooler and reduce energy cost?
Feel free to comment or get in touch: hello@green-nudges.com

From the Green Nudges Consulting team—drawing on New York City’s °CoolRoofs initiative to showcase how behavioural insights can help cities stay cooler, cleaner, and more resilient.

What unsustainable behaviour needs to change:

From concrete tiles in front gardens to sealed sidewalks and patios, many cities are suffocating under impermeable surfaces. This excessive “urban sealing” blocks rainwater, overheats neighbourhoods, and erases space for biodiversity. In the Netherlands, paved private gardens alone account for over 60% of the country’s residential outdoor area, contributing significantly to local flooding and heat stress.

Still, residents often don’t realise their own driveway or back patio plays a role. It’s a classic case of ‘diffusion of responsibility’ and ‘status quo bias’—“everyone does it” and “it’s always been there.” The default is inaction.

But what if removing pavement felt like a point of pride—not a chore?

The Green Nudge:

Since 2020, the Netherlands has hosted NK Tegelwippen, the National Tile-Flipping Championship. From March to October each year, Dutch cities compete to see who can unseal the most surface area—not just tiles, but all kinds of concrete pavement.

Residents pull up slabs, bricks or tiles and register their removals online. Each city’s tally is updated live on a national leaderboard. In 2023, Arnhem led the way, removing over 460,000 tiles, while the national count surpassed 5 million since the contest began.

So why does this work so well?

• Gamification
  – Turning a sustainability task into a game adds urgency, clarity, and fun.
  – People can track progress in real-time, earn virtual recognition, and feel rewarded for each square metre unsealed.
• Social Comparison
  – Public leaderboards show which city—or neighbour—is pulling ahead, triggering friendly competition.
  – Visibility normalises the behaviour: “If others are doing it, I can too.”
• Local Pride
  – Cities and districts build identity through participation (“We’re not just greener—we’re winning!”).
  – Municipalities often highlight local champions or give small incentives (e.g. free plants or compost).

By celebrating each removed tile as part of a bigger collective win, NK Tegelwippen transforms unsealing into a shared achievement—not an isolated effort.

And it’s easy to replicate: whether in neighbourhoods, schools or housing co-ops, the magic lies in giving people permission, visibility, and momentum to rip up what’s no longer serving them—or the climate.

Do you know clever nudges that help cities stay cooler and manage water better?
Feel free to comment or get in touch: hello@green-nudges.com

From the Green Nudges Consulting team—behavioural science consultants on a mission not just to shuffle the chairs on the Titanic, but to drive real change that makes a measurable difference. We’re always inspired by bold, practical approaches that create impact at scale.

What unsustainable behaviour needs to change:

In Bogotá’s Bilbao neighbourhood, residents weren’t sorting recyclables or handing waste to official recyclers. The real problem wasn’t bins or collection routes—it was about trust.

A behavioural diagnosis from ETHOS BT revealed a shared desire for cleaner, safer streets. Yet deep mistrust blocked collective action. Residents questioned recyclers’ legitimacy, feared being the only ones participating, and doubted neighbours would follow through. Years of conflict and neglect had frayed social ties, fuelling scepticism: “Why bother if no one else will?” Trust had to be rebuilt for collective change to stick.

The Green Nudge:

The project was commissioned to ETHOS BT, funded and delivered together with Fundación Grupo Social and Fundación Corona. As part of Fundación Grupo Social’s long-term plan in Bilbao – launched in 2023 – to strengthen trust, community bonds and quality of life.

Rooted in behavioural insights, the intervention reframed recycling as a form of connection. ETHOS BT, led by Beatriz Vallejo, champions context-driven innovation from the Global South.

• Game-led Learning: A former recycler taught children a sorting game. Kids influenced adults, wearing caps reading “I write Bilbao’s story.”
• Dialogues for Trust: Meetings built empathy and coordination between recyclers and residents.
• Sound Mural: Using recycled materials, residents co-created a mural that turned a conflict-prone wall into a symbol of community creativity.
• Visual Feedback: Installations revealed the impact of waste by linking it to local landmarks.
• Public Commitments: Pledge boards made promises visible, turning accountability into a social act.
• Neighbourhood Gamification: Block contests rewarded teamwork with paint and lights.
• Norm-Shifting Messaging: Flyers used social proof and identity cues to frame recycling as a shared achievement.

The results: In just three weeks, trust in recyclers rose by 58% (vs. 9% in the control). General trust doubled, and neighbour trust rose 24%. The recyclables collected jumped from zero to 106 kg. What began as recycling became a spark for trust and community renewal.

Have you seen other smart ways to nudge people into recycling?
Feel free to comment or get in touch: hello@green-nudges.com

From Natalia Riveros Anzola, a Bogotá-based consultant specialising in strategic communications, behavioural science, and public policy for social impact. With nearly 15 years’ experience across governments, multilateral agencies, the private sector and civil society, she designs interventions that strengthen strategy and storytelling to deliver measurable, sustainable change.

What unsustainable behaviour needs to change:

In urban summer heat, air conditioning often becomes a default behaviour—especially in poorly insulated buildings. But cooling our homes with energy-intensive appliances drives up electricity use, strains power grids during peak hours, and contributes to carbon emissions. Japan’s data shows that AC demand can rise by over 20% during summer heatwaves.

This dependency is reinforced by habits, perceived lack of alternatives, and the “invisibility” of passive cooling options. Our brains are wired to favour quick, effort-minimising fixes—even when greener solutions exist.

The Green Nudge:

Japan’s “Green Curtain” programme offers a refreshing alternative—literally. Local governments distribute free starter kits — seeds (like bitter melon, morning glory or cucumber), netting and instructions — to schools, homes and public offices. As the vines climb façades and windows, they shade walls, block direct sunlight, and cool the air through natural evaporation. Many households even enjoy fresh vegetables from their vines.

The nudge works on three key behavioural principles:

• Ease: Free starter kits lower the barrier to action.
• Salience: Green façades serve as visible cues that spark imitation.
• Social proof: Public curtain maps and neighbourhood contests promote friendly competition and norm-setting.

The results: Empirical trials show indoor temperatures drop by 2–3 °C in shaded rooms. During peak hours, this translates into an average 20% reduction in AC electricity use, helping lower energy bills, reduce emissions, and ease grid pressure. It’s a simple, nature-based intervention with measurable impact—scaled across more than 80 Japanese cities.

Do you know of any other nudges that help cool cities or fight urban heat?
Feel free to comment or get in touch: hello@green-nudges.com

From the Green Nudges Consulting team, drawing on insights from Japan’s “Green Curtain” initiative — launched in Okinawa in 2007 and now spreading to over 80 cities.

What unsustainable behaviour needs to change:

In northeast Syria—once hailed as the “breadbasket of the Middle East”—years of conflict, political instability, and recurring droughts have devastated agriculture. Farmers face a mounting set of challenges: collapsed subsidies, lack of scientific support, war-driven inflation, and intensifying climate shocks. Together, these factors are accelerating the decline of seed quality. The widespread use of low-quality wheat seeds has resulted in poor yields. With each season, this cycle worsens—further eroding seed quality and food security.

High-performing wheat varieties –adapted to drought and heat– are urgently needed. But in the absence of functioning institutions or reliable supply chains, farmers are left with few options to access suitable varieties. This isn’t just a technical issue—it’s a behavioural and systemic one. Without trusted mechanisms for learning and adoption, farmers understandably stick with what they know, even when it’s failing. Reversing this trend means rebuilding both confidence and capacity at the local level.

The Green Nudge:

In September 2022, the International Rescue Committee (IRC) launched the Farmer Seed Stewardship Network (FSSN) in northeast Syria to help restore the local agricultural system. The pilot introduced two key interventions:

• Seed Testing Competitions, where farmers ran small-scale trials over a season;
• Seed Multiplication, where promising varieties were grown on farmers’ land to improve local seed supply.

Farmers tested different wheat seed varieties, soil types, inputs and planting methods on their own land. This hands-on approach enabled rapid learning and helped identify a more drought-tolerant, high-yielding variety—later multiplied and shared more widely. Beyond improved yields, the competitions encouraged knowledge sharing and built a sense of pride among participants.

Agricultural experiments are typically led by research institutions. In contrast, this programme placed farmers at the centre. Through training sessions and WhatsApp groups, farmers were supported in their efforts, helping bridge scientific insights with traditional practices. The pilot strengthened community ties and sparked strong interest from other farmers. Now in its third year, the programme is being adapted for use in Niger and South Sudan—supporting seed system resilience in other climate- and conflict-affected regions.

Do you know of any other nudges that strengthen sustainable farming systems?
Feel free to get in touch: hello@green-nudges.com

From Yanna Vogiazou, who led the human-centred design process for the IRC’s Airbel Impact Lab (April–September 2022). She co-designed the program with the local IRC team, conducted design research, crafted & tested prototypes, and facilitated co-creation workshops with farmers and agro-dealers in Syria. Check out her website.