What unsustainable behavior needs to change:

When we look back to the fall of 2018 in Germany, one topic stands out: Climate change had the undivided attention of the media for the first time. Fridays for Future was only a few months old, but had already mobilised many people onto the streets. Consumers were becoming increasingly aware that they and their behaviour could make a difference. This sparked a newfound willingness in over half of Germans to alter their consumer habits.

Nevertheless, many remained entrenched in their old habits. This was apparent when examining the intention-behaviour gap, particularly when switching energy suppliers. For example, in 2018, of the Germans surveyed, 75% looked at alternative energy offers and prices, whereas  60% had never switched their supplier before 2018; ultimately demonstrating that consumers still had not yet opted for designated green energy.

A municipal energy supplier from Hamburg aimed to address this issue, without pointing fingers at citizens or launching information campaigns with infographics.

The Green Nudge:

While many other suppliers attempted to convince customers to act rationally through education and explanation, Hamburg Energie chose to leverage the (often) emotional nature of decision-making, as an opportunity. 

During their campaign (from October 2018 to March 2019), Hamburg Energie nudged customers to switch their energy provider for the first time ever; using the following behavioural approaches:

• Visual Cues: a set of simple yet likeable icons and emojis which merged climate change and personal energy consumption; to make the causality between the two apparent.
• Social Norms: Telling people that by choosing anything other than HAMBURG ENERGIE and/or a green energy supplier is not very “hamburgish”.
• Feedback: They made it crystal clear that consuming power from coal – is in no way, okay today.
• Social Identity and Loss Aversion: Using  meaningful landmarks and iconic sites from Hamburg, they teased what the immediate risk of losing such heritage would be like; in order to trigger a sense of identity and make citizens fear the risk of losing their beloved hometown from climate change.

The result: Hamburg Energie not only exceeded their new customer target of 5,000 for the campaign period, but surpassed it by 90%, with a total of 9,500 new customers acquired. Of these, at least 5,000 originated from the dominant supplier, Vattenfall. This resulted in a customer growth rate of 7.1%, marking a staggering 380% increase, compared to the average growth in comparable periods from previous years.

Are you aware of any other nudges that help promote sustainable products or services? Feel free to get in touch: hello@green-nudges.com

What unsustainable behavior needs to change:

Many Dutch municipalities face challenges in encouraging residents to dispose of their waste properly. Regrettably, bags filled with garbage and other debris often end up beside underground waste containers rather than inside of them. Typically, a polluted environment tends to attract more litter and antisocial behaviour, whereas a clean and orderly environment tends to stay cleaner (the Broken Windows Theory).

Concurrently, traditional communication methods like posters, often fail to produce effective results, particularly in diverse neighbourhoods with various ethnic backgrounds. This prompted a search for a more universal approach. The team at Fama Volat sought to explore whether scent could serve as a potent, universal language to address this issue.

The Green Nudge:

The creative agency came up with the idea to use sensory priming to encourage proper waste disposal. By dispersing a fresh scent reminiscent of cleaning products, they activate the brain’s association with cleanliness, subtly encouraging individuals to maintain cleaner environments. 

To implement this, „birdhouses“ designed to release lime-scented pellets were installed around problematic waste container sites. The birdhouses, closed off to birds but filled with scent pellets, allowed the wind to spread the lime scent, which significantly helped to reduce the misplacement of waste and thereby promote cleaner behaviour amongst users.

The result: A study of 38 underground waste containers—18 with scented birdhouses (study group) and 20 without (control group)—revealed a 13% decrease in incorrectly placed waste in the study group. Whereas, the control group saw a 214% increase. On top of that, there was a 24% reduction in litter in the neighbourhoods surrounding the problem locations.

Are you aware of any other nudges that help to prevent littering? Feel free to get in touch: hello@green-nudges.com

What unsustainable behavior needs to change:

Diets heavy in animal-based foods (meat, dairy, fish and eggs) come with high climate, environmental and public health costs.  From greenhouse gas emissions to land use, research has evidenced that plant-based diets are a healthy and sustainable alternative that countries in the global North should embrace to significantly reduce food-related emissions.

There are however social, cultural, psychological, and situational factors that stand in the way of plant-based diets from being widely adopted. In this context, editing one’s options of choice can successfully increase the consumption of plant-based alternatives.

The Green Nudge:

Cambridge University researchers investigated whether increasing the proportion of plant-based options on a menu can lead to increased consumption of vegetarian and vegan dishes among college students. Results suggest that this simple and cost-effective nudge can effectively encourage sustainable food choices.

The study modified the menu of three college cafeterias so that 50% of the dishes on offer were plant-based (vegan or vegetarian). A total of 94.644 meals were assessed and previous students‘ consumer choices were anonymously recorded.

The result: doubling the availability of plant-based options increased sales  and consumption  of plant-based foods, particularly amongst those who usually preferred meat dishes. In fact, meat sales decreased by 40.8%, 61.8% and 78.8% in the three cafeterias, respectively.

The study evidenced that, even though personal taste matters, food choice is also influenced by availability. Therefore, simply increasing the availability of plant-based options can gently nudge consumers to choose the most sustainable option and provide a gentler alternative to more explicitly top-down initiatives such as „meatless Monday“.

Are you aware of any other nudges that promote plant-based diets? Feel free to get in touch: hello@green-nudges.com

What unsustainable behavior needs to change:

Gelderland Province offers abundant natural beauty that’s cherished by both humans and animals. Nevertheless, where nature and human activities intersect, accidents can occur. In the Netherlands, thousands of wildlife collisions happen annually, often due to speeding motorists unaware of animals along the roads. This behaviour poses risks to both traffic safety and animal welfare. 

Additionally, the annual shift in daylight patterns brings earlier darkness. While wild animals maintain their regular rhythms, human travel occurs later; thus contributing to an increase in wildlife collisions.

The Green Nudge:

To mitigate this issue of wildlife collisions, creative agency ANDC has developed interventions targeting motorists‘ behaviour.

Their research identified three promising approaches: capturing attention and offering actionable perspectives, heightening risk perception, and reinforcing desired behaviours among the respective target audience (drivers).

Signs were created to welcome motorists into the wildlife domain, fostering a sense of being “guests” in the animals‘ territory. These signs concluded with a clear demarcation, distinctly outlining the area’s boundaries. Furthermore, in order to amplify the perception of risk, a dynamic light sign was developed to indicate the frequency of wild animal crossings.. Finally, strategically positioned silhouettes of wild animals along the road served as attention-grabbing symbols to evoke associations with the local wildlife.

The result: This set of interventions significantly reduced the speed of motorists. In the short term, the average speed decreased by 3.64 km/h. Over the long term, the average speed was consistently lower, showing a reduction of 5.19 km/h on average.

Are you aware of any other nudges that help to protect wildlife? Feel free to get in touch: hello@green-nudges.com

What unsustainable behavior needs to change:

Water waste in hotels resulting from showering is a significant problem, especially when guests do not concern themselves with the extra costs. On average, hotel guests likely shower for 8-10 minutes, a significantly increased use of water as compared to a more economical 5-minute shower when at home.

This behaviour is simply bad for the environment and contributes to unnecessary water depletion. And moreover, because hotels consume thousands of litres of water on a daily basis to accommodate this increased demand, hotel operational costs are also inflated.

The Green Nudge:

As part of its ongoing mission to reduce water usage, Disneyland Paris is testing special water-saving shower heads at Disney Sequoia Lodge. These illuminated showers start with a soothing blue for the first 10 litres; switch to an encouraging green up to 20 litres; then shift to a reflective purple when the guest uses up to 30 litres; and finally signal with a bold red, when guest usage exceeds 30 litres. This clever use of universally recognized colours not only promotes shorter showers, but also merges significant behavioural change with enjoyment.

The result: The „Hydrao shower heads“ have successfully reduced water use in showers by 22% at the testing lodge. Pending their continued effectiveness, the resort plans to expand the installation of these efficient shower heads and water-saving toilets in all of Disneyland-Paris hotel rooms.

To boost conservation efforts even further, Disney-Paris ought to consider enhancing the water-light system by activating the red light earlier.

Are you aware of any other nudges that help to save water? Feel free to comment or get in touch: hello@green-nudges.com

What unsustainable behavior needs to change:

Deutsche See, renowned for its fresh and frozen fish and seafood, faced a recurring issue: employees habitually left the refrigeration unit doors open during operations, resulting in increased energy consumption as the cooling systems had to work harder.

As we’ve seen in our previous nudge, the ‘radiator paint’ in public buildings developed for the City of Copenhagen – people often fail to change unsustainable behaviour when unable to assess abstract factors; such as temperature increase and subsequent energy waste.

For employees working in the refrigeration units at Deutsche See, the consequences of temperature increases and the associated energy implications remain intangible and often go unnoticed.

The Green Nudge:

What unsustainable behavior needs to change:

India used to have a significant issue with the habitual practice of open defecation, which led to the contamination of drinking and bathing water. To address this issue, the Government of India initiated the Swachh Bharat Mission or Clean India Mission in 2014. The country-wide campaign aims to eliminate open defecation and improve solid waste management, promoting a cleaner and healthier environment for all.

The Kumbh Mela is one of the world’s largest religious festivals, attracting around 200 million people over 55 days. However, in terms of sustainability, the festival presents unique challenges – particularly regarding open defecation and water waste.

The Green Nudge:

To effectively address the issue of open defecation, the organisers of the 2019 Kumbh Mela festival incorporated behavioural insights to implement a proactive solution. They recognized that breaking unsustainable habits can be difficult, therefore, they developed an action plan that taps into various nudge tactics; namely encouraging individuals to use toilets instead of practising open defecation.

Default: The organisers strategically placed toilets near religious sites to make them more convenient and comfortable than when openly defecating. This approach is an example of a default option, where the preferred behaviour is made the standard and more attractive than the alternative. Establishing a new default option is an effective means of influencing the hierarchy of choice for individuals and thus promoting positive habits. By making the preferred behaviour the default as well as a more attractive choice, individuals are more likely to adopt it. 

Feedback: In addition to the default nudge, the organisers installed over 122,500 eco-friendly „smart toilets“ to cater to the needs of pilgrims and tourists. These toilets were equipped with sensors that provide immediate feedback to users on their water usage. By making the abstract (amount of water used) more concrete, this encouraged visitors to be mindful of their behaviour. The smart toilets incentivized water conservation by displaying information such as the amount of water used for flushing and handwashing.

The result: 9,888 MT of waste collected during the Kumbh Mela 2019, sent to Baswar solid waste treatment plant for scientific disposal, ensuring zero waste disposal in Ganga or Mela area.

This approach can be replicated in other contexts throughout India to effectively address the issue of open defecation and therein promote sustainable practices.

Are you aware of any other nudges that help to establish more sustainable habits? Get in touch: hello@green-nudges.com

What unsustainable behavior needs to change:

Radiators in public buildings such as schools, libraries, etc. are often wasting energy in rooms that are not being occupied or where windows are opened. 

According to a study conducted by the Department of Energy and Climate Change in the UK, leaving a single window open overnight during winter can increase heating energy consumption by up to 8%. This means, if a person’s heating bill for the winter is $1000, leaving the window open for one night could potentially cost an additional $80.

The core problem: People cannot see if the radiator is hot, medium, or cold making it difficult to know if they should turn down the valve. 

The Krukow consultants worked together with the city of Copenhagen to investigate what kind of nudge solutions could be developed to reduce heat waste from radiators. 

The findings can be transferred to both companies and private households. 

Here is what Krukow found:

1. The main behavioural barrier for turning off a radiator when i.e., opening a window is lack of visual feedback. When opening a window, we pay little attention to the radiator and forget to put a hand on it to feel if it is hot or cold. 
2. There is nothing in the visual design of the radiator reminding people to check the heat of the radiator before opening the window.
3. When a window is open near a warm radiator, the heat goes up to compensate for the drop in room temperature making the heat of the radiator instantly increase even more. 

In a nutshell: People often fail to change unsustainable behaviour when unable to assess abstract factors like room temperature or air circulation.

The Green Nudge:

Krukow came up with the idea to add heat-sensitive paint to radiators, changing colour from blue to red to provide visual temperature feedback. 

When a radiator in a room compensates for a drop in temperature by increasing heat output, the heat-sensitive paint on the radiator’s surface reacts to the immediate increase in temperature by changing colour. This colour shift provides an immediate visual cue to pupils, employees or visitors in public buildings, indicating when to turn off the radiator. This way the City of Copenhagen could effectively reduce energy waste and save money on heating bills.

Visual feedback, like the blue stripe on a baby’s diaper or a razorblade’s colour change, makes the abstract concrete and is a great way to trigger behaviour change, as demonstrated by the radiator paint example.

What unsustainable behavior needs to change: Well, I confess it: I used to brush my teeth during a long, hot shower. It just felt comforting and self-indulging. But it started to feel wrong- to waste so much water and energy. But wait, was it a lot? How much water and energy is needed for a shower? Does it make a big difference if I shower for 2, 5 or 10 minutes? I had no clue, because it was too abstract. 

In most households the shower is the 2nd biggest energy consumer (after heating). In Germany, people spend between 8-12 minutes under a running hot shower with 40°C (104°F). That means approximately 20% of the total energy used to heat water and ~16 liters of water per minute. 

In order to saving energy, we could either shower shorter or reduce the temperature of the water. The first problem here: showering is extremely habitual and the shower is also the place where your mind wanders and you forget time easily. The second problem: although reducing the temperature by 2-3°C would make a difference, guessing the temperature is as inaccurate as trying to hear the decibel of a winter car tire. 

What we need is a feedback mechanism that makes the abstract energy and water consumption more concrete, more salient. Something that nudges people into shorter and colder showers.

The Green Nudge: Swiss company Amphiro came up with a digitally enabled behavioural intervention: a smart shower meter that provides real-time feedback of your energy and water consumption during the shower. 

Researchers from the ETH Zürich and the University of Bamberg conducted a natural field experiment with an uninformed sample of guests at 6 Swiss hotels (265 rooms, N = 19,596 observations). 

The rooms were equipped with smart shower meters in their hotel rooms. The devices measured the energy and water consumption of every shower taken, and displayed feedback on each ongoing shower in real time. 

Information that was shown on the display:

• total water consumption in liters, 
• total energy use in kWh, 
• a dynamic rating of the current energy-efficiency class (A–G) and 
• a four-stage animation of a polar bear standing on a gradually melting ice floe 

The result: a large and significant energy-conservation effect of 11.4% or 0.215 kWh per shower (vs control group that was shown only temperature).

While this does not fully translate to household settings, it demonstrates that feedback can be an impactful nudge to preserve resources like energy and water. Especially when you scale this up for a larger group.

Full article in Nature.

What unsustainable behavior needs to change: In 2013 when the Green Party in Germany demanded a veggie/vegan day in company, school or university canteens, the outcry was massive: “Cancel culture.” “Don’t take away our freedom!” “Political paternalism!”. The idea was not only to create awareness for a diet with less meat but to directly reduce emissions.

However we need to recognize that meat consumption is a big driver for CO2 emissions that expedites  global warming. Western Europeans eat 10x more meat than people living in India. Eating meat has societal as well as personal consequences: A fat-heavy diet often leads to obesity and severe health issues like heart attacks.

The problem: most often the negative externalities of meat consumption are hidden. Most people don’t know how much CO2 emission their steak is responsible for how a meat dish compares to a veggie option.

So the question is: how can we become choice architects that just nudges a decision instead of telling people what to do.

The Green Nudge: In a joint effort the Ludwig-Maximilians-Universität München, Humboldt-Universität zu Berlin and the Aalto University wanted to examine if making negative environmental impacts like CO2 emissions more salient, would nudge people to adapt their choices.

In a 10 day field experiment in one of the biggest university canteens in Munich with over 8.000 visitors (during that 10 day time period), the researchers introduced menu displays showing the food option but also the environmental externalities like the CO2 footprint

The interesting bit: their experimental design included testing different options of how to visualize the negative footprint.

Variables were:
➡ the negative cost in €
➡ the amount of an individual’s daily CO2 budget spent
➡ the amount of CO2 emissions

They introduced traffic light colors: green for dishes with low CO2 emissions, yellow for more emissions and red for the “climate-killer-lunch”.

The result: the demand decreased for CO2-intensive choices with meat and fish and thus reduced the footprint of the total lunch menu. The researchers could observe the biggest effect when visitors learned how much environmental cost (in €) their lunch would cause. So making something intangible more salient resulted in almost 10% less CO2 emissions compared to days when they didn’t show any negative environmental impact on the menu displays.