The Little Book ofGreen Nudgesxx
40 Nudges
to Spark
Sustainable
Behaviour onCampus© United Nations Environment Programme and GRIDArendal, 2020
ISBN: 978-82-7701-198-1
Recommended citation:
United Nations Environment Programme, GRIDArendal and Behavioural Insights Team (2020).
The Little Book of Green Nudges: 40 Nudges to Spark
Sustainable Behaviour on Campus. Nairobi and
Arendal: UNEP and GRID-Arendal.

Illustrations and icons by Studio Atlantis.

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The designations employed and the presentationof the material in this publication do not imply theexpression of any opinion whatsoever on the partof the United Nations Environment Programme or
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Acknowledgements
This publication was commissioned by the United
Nations Environment Programme (UNEP) under the
direction of Mari Nishimura, supported by Carina
Mütschele and supervised by Sam Barratt. Jessica
Barker and Toby Park of the Behavioural Insights
Team were the authors. Lisa Hymas of GRIDArendal was an editor and project coordinator. Trista
Patterson of GRID-Arendal was an editor. Illustrations
and graphics by Studio Atlantis (Elisa Campagnaroand Nieves López). Copy-editing by Guendalina De
Luigi (GRID-Arendal). Layout by GRID-Arendal. We
thank the participants of the Behavioural Economics
Workshop that was held in Nairobi in 2019. We also
thank experts who reviewed this publication, inparticular, Michelle Fadelli (UNEP), Garrette Clark(UNEP), Melissa Goodall (Yale University), Julie
Newman (MIT), Charlotte Bonner (SOS), Iain Patton(EAUC), John Robinson (University of Toronto),
Vanessa Timmer (One Earth), Debra Rowe (USPartnership for ESD), Tim Carter (Second Nature),
Orlando Sáenz (ARIUSA), Gloria Ordóñez (UNEP),
Suchada Chaisawadi (KMUTT), Fengting Li (CGUN/
Tongji University) and Jessica-Qian Jia (Tongji
University), as well as 45 universities around theworld that contributed case studies about nudging.

The Little Book ofGreen Nudges
40 Nudges to Spark
Sustainable Behaviour on Campus
FOREWORD

4

WHAT ARE GREEN NUDGES?

6WHY USE NUDGES?

7

WHO CAN USE GREEN NUDGES?

8

HOW TO NUDGE: GO EAST

9MAKE IT EASY

10

MAKE IT ATTRACTIVE

16

MAKE IT SOCIAL

22

MAKE IT TIMELY28

FIVE STEPS TO MAKE YOUR NUDGE A SUCCESS 34
CHECKLIST FOR SUCCESSFUL NUDGES

41

ENDNOTES

42

RESOURCES AND REFERENCES

44

GREEN NUDGES AT A GLANCE

46

WHICH GREEN NUDGES WILL YOU USE?

47

FOREWORD
Students around the world want the placesin which they study to reflect their values.
Increasingly, that means taking a firmer standon environmental issues and the climate crisis.
We have seen this in a recent National Unionof Students survey that found 86 per cent of
first-year students in the UK want their higher
education institutions to actively incorporate
and promote sustainable development.1 Thiswas further reinforced in a Princeton Review
survey that found two-thirds of student

applicants (or their parents) would like totake a college or university’s commitment
to the environment into consideration whenchoosing where to study.2 Calls for divestment
from fossil fuels are showing how students
are pushing their universities to make majorchanges to address the climate crisis. And
this drumbeat calling for action is only
getting louder.

Behavioural science shows that a simple“nudge” towards everyday greener decisions
is a powerful spur to environmental action
for students and other campus community
members. Techniques such as gentle
persuasion, changing the framing of choices,
resetting default options or harnessing social
influence can all lead towards sustainableconduct and an eco-friendly campus.

Change is clearly needed, but change doesn’t
have to mean radical upheaval per se.

Now is the perfect time for trying green
nudges, as higher education institutions are
redesigning systems and routines in the wakeof the emergence of COVID-19. This is a timely
moment when students and staff can be
encouraged to consider new behaviours andhigher education leaders can consider how tobuild back better.
Nudges can not only be effective, but also areoften cost-effective and time-efficient. They
focus on new behaviour, not new equipment,
and can succeed by shifting existing systems
and processes rather than creating new ones.
Nudges that save energy and resources help
save the planet, but they also save money foruniversities and students.
The UN Environment Programme (UNEP) is
now embracing nudging as a strategy to help
meet the Sustainable Development Goals(SDGs) and protect the global environment, withsupport from the Behavioural Insights Team.
We can see that when we nudge people away

4 The Little Book of Green Nudges

from overconsumption and waste, and towards
energy efficiency and lower-impact lifestyles,
we are playing a part in fighting climate change
as well as preserving the natural world in which
we live and on which we rely.
Nudges are not the only tool we have –and shouldn’t be used at the expense ofstrong policy and regulation – but they are an
important part of the solution.
A key tenet of a successful nudge is thetiming of the intervention. When better tointervene than during students’ formative
years on campus? Higher education
institutions are the incubators of our future
entrepreneurs, decision-makers and trendsetters, and of their increasing consumer
power. Nudges on campus are particularly
powerful because it is here that students– often away from home for the first timeand able to find themselves – are forming
new routines and new identities. We hopethat sustainable habits and environmentallyconscious behaviours that are developed
during this period can last a lifetime.
This little book shares inspiring, evidencebased examples of nudges, many of whichhave been proven to work on university
and college campuses. But more importantly,
it provides the practical information needed
to create and test new nudges, tailored todifferent and specific campus communities.

Whether student or staff, in Africa, Asia, theAmericas or anywhere else, if you want to create
positive change on campus, this book is for you.
We hope it will inspire, challenge and influence,and its ideas and the experiences it triggers will
be shared far and wide.
The potential to make our universities andour societies greener is enormous, and we don’t
have time to waste. A small nudge can go along way.

Inger Andersen
Executive Director
UNEPDavid Halpern
Chief Executive
Behavioural Insights Team

Join UNEP in making an impact on campuses through nudging
The higher education community has unique
opportunities to influence the citizens of
tomorrow and to test nudges in real-world
laboratories.
“The Little Book of Green Nudges” offers apractical framework and 40 nudges that canbe adopted by colleges and universities, fromthe small-scale to the large, depending on
your resources and context. By embracing thisapproach, leaders and activists on campus
can facilitate more sustainable decisions andhelp reduce the approximately 75 per cent of
personal emissions that come from what weeat, how we travel and the homes we live in.3
This book does not contain all the answers
on how best to change behaviour in every
circumstance. Nudging projects will playout differently in different parts of the world,
on different types of campuses, and among
different genders and cultural groups. But
everyone can learn from insights gained along
the way.
This book contains a wealth of ideas andtips, but it’s only a starting point. UNEP needs
you to take this initiative to the next level.
Many colleges, universities and other higher
education institutions across the globe havealready jumped on board to contribute ideas,
test nudges, share experiences and learn fromothers. Together we can make nudging more
successful and have a real impact.
We hope you and your institution will join us!
Please visit unep.org/nudges.

The Little Book of Green Nudges 5

WHAT ARE GREEN NUDGES?
There are many different approaches tobehaviour change, from enforcing regulation
to providing information. In this little book,
we focus on nudges: positive and gentle
persuasion to encourage sustainable behaviour
on higher education campuses. For example,
putting more sustainable food in a prominent
position in the student canteen would be anudge, still leaving students free to eat what
they want. So would automatically enrolling
students into a bike-sharing scheme, regardlessof whether they choose to use it. In bothcases, these simple changes would make thesustainable choice a little easier, more salientand seemingly more normal.
Nudging is based on an understanding of thepsychology of decision-making. Our brains
have limited resources to make sense of aworld that is complex and uncertain, whichmeans that we use mental shortcuts thatmake our behaviour highly context-dependent:
for example, “do what everyone else is doing”
or “take the easiest option”. Also, a lot of our
behaviour is automatic, as we follow ingrained
routines or act on auto-pilot. With knowledgeof these cognitive processes, we can makechanges to the options people have (the“choice environment”) in order to encourage
certain choices, or we can explicitly design
choices to harness or overcome common
cognitive biases.

6 The Little Book of Green Nudges

positiveand gentle
persuasion
to encouragesustainablebehaviourWHY USE NUDGES?
Nudges help people live their values

Nudges are cost-effective

Many people intend to eat healthily, savemoney or live more sustainably, but don’t follow
through with their intentions. This is partly
because we prioritize our short-term desires(chocolate cake or a new pair of shoes) overlong-term aspirations. It’s also partly because
our behaviour is unconsciously affected by thephysical and social context in which the easy ordefault choices are often not the most healthy,
economical or sustainable. Nudges can makepeople’s lives easier, happier and more rewarding
because they help people align their daily
decisions with the values they already have.

Nudges are often cheap to implement, as
they frequently involve changing the way
choices are presented instead of rebuilding
infrastructure or buying new equipment.
Nudges that help to conserve resources canin fact save universities money. For example,
a small university department in the UK could
save more than £1,000 per year by turning
off its lights every night,5 and a nudge to help
achieve that goal could be very low-cost,such as printing reminder notices to put up
at light switches.

Nudges can work better than raisingawareness
Because there is a gap between what we intend
to do and what we actually do, it is generally
more effective to focus, as nudging does,on changing behaviour directly, rather thansimply raising awareness. Awareness andintentions still matter, as they make behaviourchange easier, but they are rarely enoughalone: although many people say they want to
consume more sustainably, they don’t do soin practice.4 This means that while a poster
campaign on campus about the environmental
impacts of driving might help people learn
about the issue, a nudge offering more bikeparking spaces and fewer car parking spaces
has a higher likelihood of reducing car usage.

Nudges are needed now
With public concern about climate change
and the environment at an all-time high,there is clearly no absence of motivation forsustainability. But it can be hard to movepeople from motivation to concrete action,
especially when sustainable choices are more
complicated or inconvenient, or require us togo against defaults and established norms.
This is where you can help – your nudges
can remove barriers and facilitate everyday
sustainable behaviours.

The Little Book of Green Nudges 7

WHO CAN USE GREEN NUDGES?
If you work or study on a higher education campus,
this book is for you!
Nudges tend to be relatively simple to implement,
so you don’t have to be a policymaker with a lotof influence and resources in order to put a nudge
into effect. Perhaps you are …
• a university leader looking to prioritize
environmental responsibility on campus• a sustainability manager wanting to make an
impact on a tight budget• a student interested in trying out something
new and making a difference

Nudgestend tobe relatively
simple toimplement

many
insights
into human
psychology
are applicablearound theglobe

This little book brings together a wide range ofnudges, well supported by evidence, and many
already tested by colleges and universities. The
40 featured nudges are grouped into 12 broad
strategies, which can be adapted and appliedby different people to different behaviours in
different contexts.

Nudges can be effective all around the world
Nudging works by focusing on aspects ofhuman behaviour that are largely universal.
Although most behavioural science researchhas been carried out in Western Europe andNorth America, many insights into human
psychology are applicable around the globe.

8 The Little Book of Green Nudges

For example, humans everywhere respond tosocial norms, and our dependence on habit
and other non-conscious mental processes
is rooted deeply in our evolutionary make-up.
The particular social norms and habits on
your campus may differ from those on othercampuses, but you can still use similar
strategies for nudging. Likewise, social
norms may differ by gender, age group, orother social or cultural identity, but yournudges for particular target groups can takethe same underlying approach.

HOW TO NUDGE: GO EAST
If you want to encourage a behaviour, make it
Easy, Attractive, Social and Timely.6
Easy
People often take the path of least resistance. You
can therefore encourage desirable behaviours byremoving small frictions or hassles, by defaulting
people into the desirable choice, or by redesigning
the way choices are presented to make thedesirable behaviours easier.

TimelyPeople are creatures of habit, so nudges
are most effective at moments of change in
people’s lives. We also have a deep tendency
to emphasize the present more than the future.
You can harness these tendencies by timing
campaigns strategically, highlighting theimmediate benefits of sustainable actions, andhelping people plan ahead.

In the following pages, we provide ideas ineach “EAST” category for nudges you could
implement on your campus. Use the icons
below to find nudges in eight target areas ofbehaviour change.
Energy conservation
Water conservation
Sustainable diets

Attractive
Humans are more likely to adopt a behaviour
when it captures our attention or is in linewith our motivation and beliefs. You can draw
attention with visual cues that are particularly
relevant or noticeable, and leverage motivation byemphasizing the positives and using incentives.

Reduced material consumption

SocialHuman behaviour is hugely influenced by what
others around us are doing. You can promotedesirable actions by highlighting the fact that
other people are adopting them. You canalso make behaviour more publicly
visible, and emphasize opportunities
for people to help each other.

Engagement and support for change

Sustainable and reduced travel
Reduced food waste
Recycling

The Little Book of Green Nudges 9

MAKE IT EASY
Use defaults

Set the norm that diners will use their own
cup and cutlery

The nudge: Make the more sustainable behaviour the default option.
Evidence that it’s effective: Defaulting customers into a renewable electricity
tariff in Germany led to a 10-times increase in the number of people on that tariff.

7

Why it works: People tend to stick with the default choice or the status quo.
This is because we don’t engage consciously with many of our daily decisions, or
we lack the motivation to take a different course of action. Defaults are also often
perceived as a “safe bet” or an implicit recommendation.

makethe moresustainableoption, such asa plant-based
dish, thedefault

How? At cafeterias, coffee shops and catered
events on campus, let people know that they are
expected to bring and use their own reusable
cups and cutlery. Only provide disposable cups
and cutlery if people specifically request them.
Who might be involved? Campus catering
coordinators

Make the most sustainable meal thedefault choice
How? At catered events on campus, make themore sustainable option, such as a plant-based
dish, the default. If attendees want anotheroption, such as red meat, they must pre-order it(the opposite of the current norm, which often
requires people to pre-order plant-based food).
Who might be involved? Campus catering
coordinators, catering companies

10 The Little Book of Green Nudges

makeremotedial-in thedefault
optionDefault to eco settings on appliances andelectronics
How? Set heating and air-conditioning
systems to more moderate temperatures, andautomatically turn them far down or off overholidays, unless overridden. Set dishwashers
and other appliances to run on eco settings. Set
printers to double-sided mode by default,8 andfill them with recycled paper. Hold “set up yourcomputer” drop-in sessions to help people set
their own laptops to modes that will save energy
and print double-sided.
Who might be involved? University
administrators, campus building managers,
IT department

CASE STUDYThe University of Malta has reduced paper
use by establishing a default of having
students digitally submit assignments andresearch ethics applications. It has also
used defaults to reduce energy consumption:
the campus replaced stand-alone airconditioning units with a centralized
system that has time controls and default
settings to moderate temperatures.

CASE STUDY

Make remote dial-in and sustainable travel
the default options
How? For meetings, conferences and events on
your campus, make remote dial-in the default
option for attendees who do not live nearby. For
events elsewhere that your staff and students
are invited to, make remote dial-in the default
and require attendees to make the case to go inperson. When people do have to travel, set the
expectation that they will use public transit, takethe train or ride-share whenever possible. Whenbooking flights, default carbon offsetting into
the process.
Who might be involved? University
administrators, department administrative staff

At Portland Community College, US,employees’ computers are on a default
setting to shut down overnight. The college
adopted this system after trying otherapproaches that did not have an impact,
including sending email prompts and sharing
information on the college website. To makethe case for implementing the default, anight audit was conducted to see how much
equipment was being left on, and then the IT
department was brought in to help estimate
how much energy and money could be saved
each month by shutting computers down
automatically. Approval was then granted to
implement the nudge, and now the college
estimates that the default shutdown has
saved several thousand kilowatt-hours ofelectricity per year.

The Little Book of Green Nudges 11

MAKE IT EASY
Remove or add frictions
The nudge: Remove small barriers to sustainable behaviour, and add barriers
to unsustainable behaviour.

Evidence that it’s effective: The recycling rate in an American campus
building increased after the introduction of bins with specialized lids, which
made it easier to see which items should go where (removing friction).9 Less
food was wasted when an American university cafeteria did not provide trays,
as people had to make an effort to get more food (adding friction).10

Why it works: We’re disproportionately impacted by small “friction costs”
or points of hassle. Removing these frictions can help people act on theirintentions to be more sustainable, while introducing frictions can discourage
undesirable actions.
Hold
free
bike repair
events on
campusAalto University in Finland has made it easier to cycle tocampus by installing bike repair stations and parking.

Make it easier to cycle around campus
How? Offer bike-sharing programs at convenient
locations on campus, or offer students hasslefree or discounted access to municipal or private
bike-sharing schemes. Hold free bike repair
events on campus. Create well-marked, safe
cycling routes. Provide showers and convenient
cycle storage.
Who might be involved? Students, university
administrators

12 The Little Book of Green Nudges

Introduce applications for parking cars on
campus
How? Require people wishing to drive to campus
to register their cars or apply for a parking
permit, even if doing so is free. Increase thefriction further by having permits last only for a
day or a week, so that people have to reapply.
Who might be involved? Campus parking
administration

CASE STUDY
University College Cork, Ireland, reduced thehassle of using reusable cups by installing
cup washers on campus, then saw a
20 per cent increase in reusable cup use.

Make it harder to let taps and showers run

CASE STUDYHow? Install shower timers in halls of residence.
Equip sinks with push-button taps that
automatically turn off after 30 seconds.
Who might be involved? University
administrators, campus building managers

In university cafeterias, offer smaller
plates and no trays

Install
showertimers inhalls ofresidence

How? At buffet-style campus cafeterias, help
prevent food waste by providing small plates
rather than large ones and not supplying
trays. This makes it more difficult to take large
amounts of food, but leaves people free to get
more later if they are still hungry.
Who might be involved? Campus catering
coordinators

The University of Winchester, UK, has madeit easy for students to donate unwanted
goods to local charities supporting
homeless and vulnerable communities
by providing “collection packs” at student
accommodation, including donation bags
and category stickers for sorting them. This
“Bag It Up” campaign was started by the
University Environment Team, the housing
and cleaning staff, student representatives
and the charities. It required collaboration
with senior management, the housing
department and the cleaners, whose work
practices changed due to the scheme.
Resistance to changed work practices
could have been a barrier, but the cleaners
were supportive once the organizers
explained their intentions. The initial costof the donation bags was offset by thesavings from reduced waste disposal.

CASE STUDYThe University of St Andrews, UK, hasremoved trays and reduced the size of plates
to cut food waste in student dining areas.

The Little Book of Green Nudges 13

MAKE IT EASY
Change the choice environment
The nudge: Facilitate sustainable choices by making them more accessible
and available.
Evidence that it’s effective: Diners were more likely to choose sustainable
food options in British and Swedish university canteens when these options
were listed at the top of the menu, made more visible, or made more available
relative to other options.11,12

Why it works: Our subconscious decision-making is influenced by theavailability and positioning of items: we’re more likely to choose what is moreavailable, easier to reach or first on a list. We also evaluate choices relative tothe other options that are present, so a large cup of coffee would seem small
compared to an extra-large one, but not compared to a small one.

CASE STUDYAt Dalhousie University, Canada, students
helped the Office of Sustainability analyse thenumber and types of waste bins and signage
on campus. Based on this research, students
and staff removed 4,500 individual rubbish
bins, added more than 3,000 recycling andcompost bins, and placed more than 4,000
signs and stickers. In addition, the university
used choice architecture to encouragesustainable transport, by installing more bike

14 The Little Book of Green Nudges

racks, bike pumps, bus shelters and electricvehicle infrastructure. Their tips for successful
implementation include consultation andengagement with all parties involved, including
users; creating business cases to identify andsecure funding; agreeing on a maintenance planwith custodial staff and facilities management;
and creating opportunities for students toresearch issues on campus and showcase
how their findings are having a real impact.

Make sustainable options more prominent
How? Place foods that are more sustainable atthe front of fridges or counters, at eye level andnear checkouts. Put recycling bins in front of
rubbish bins.
Who might be involved? Campus catering
coordinators, campus building managers

Offer sustainable substitutes for common
foods
How? Provide alternative food options thatare familiar but more sustainable, such as aburger with a patty made of beef and mushroom
instead of a standard beef burger.
Who might be involved? Campus catering
coordinators

Make sustainable options more prevalent
How? Provide a higher proportion of plant-based
dishes and products in cafeterias and shops.
Provide more bike parking relative to car parking.
Provide more recycling bins relative to rubbish
bins, and make sure they are in locations where
they are especially needed, such as kitchens andcafeterias.
Who might be involved? Campus catering
coordinators, campus building managers,
university administrators

Providefamiliarbut moresustainablefood
options

The Little Book of Green Nudges 15

MAKE IT ATTRACTIVE
Draw attention
The nudge: Attract attention to a sustainable option by using
messaging that is personalized or relevant for your specific target
audience. Make sustainable actions or infrastructure stand out withvisual cues.
Evidence that it’s effective: Study participants who read messages
about the local effects of climate change (making it more personally
relevant) reported higher engagement than those who read about
global effects.13 Painting green footsteps on the ground leading up tobins (an eye-catching cue) resulted in less litter on the street aroundthe bins in a Danish city.14

Why it works: We have finite attention and mental capacity, so we’redrawn to stimuli that stand out, are engaging and are relevant to us. This
includes seeing our names and seeing bright and contrasting colours.
CASE STUDY
Recycling is eye-catching at Mahidol
University, Thailand, where a “recyclable
waste bank” project has created recycling
points that mimic banks’ transaction andwithdrawal systems. When people deposit
recyclable items, they get a bank statement
showing the value of those items, and they
can withdraw this in cash or save it in their

16 The Little Book of Green Nudges

account. The university’s IT division createdsoftware for the project, and the “banks”
have now been expanded beyond campus
to local elementary schools. The biggest
barrier to implementation was raisingawareness of the banks, so the university
puts effort into promoting them to newstudents and staff.

Make recycling bins eye-catching
How? Use design and cues in the physicalenvironment to draw people’s attention torecycling bins rather than rubbish bins, forexample by painting them conspicuous coloursor placing footstep markers leading up to them.
Who might be involved? Campus building
managers

Install smart meters with feedback
displays

Indicate food “use by” dates clearly

How? In student halls of residence anduniversity department buildings, provide smart
meters for electricity, gas or water that show
how much is being consumed in real time, andinclude information on the associated costs,
making the impacts of consumption obvious
and personally relevant.

How? For food packaged and sold on campus,
such as sandwiches, provide a single label typeto tell consumers how long the food is good for(“use by” a certain date), information that stands
out and is unambiguous. This prevents people
from getting confused by other labels (e.g. “bestbefore” and “sell by” dates) and throwing out
food when it is still edible.

Who might be involved? Campus building
managers, university administrators

Who might be involved? Campus catering
coordinators, food companies

CASE STUDY
Tongji University, China, encourages
students to sort garbage and recycling
correctly with waste-sorting game machines.

Personalize messages
How? Address communications and campaigns
to recipients by name when possible, and tailor
them to specific interests or circumstances. For
example, students living in campus buildings
might get different energy-saving tips than thoseliving in off-campus accommodations.
Who might be involved? Campus sustainability
coordinators, student sustainability groups

The Little Book of Green Nudges 17

MAKE IT ATTRACTIVE
Frame messages positively
and highlight co-benefits
The nudge: Use positive messages that will resonate with your target
audience and make them feel good about themselves. Highlight the cobenefits of a sustainable behaviour, such as how it will save people moneyor make them healthier in addition to conserving natural resources.
Evidence that it’s effective: A survey of UK citizens who had adopted
lower-carbon lifestyles found that concern for “the environment” wasoften not their primary motivation.15 People in a study who were asked toimagine the positive emotion of pride expressed more pro-environmental
intentions than people asked to imagine guilt.16

Why it works: People tend to find messages based on pride, fun andhumour more compelling than those based on guilt. People are also
driven by desires to save money, have fun, get healthy and be social.

18 The Little Book of Green Nudges

Promote plant-based food as aspirational,
delicious and filling
How? Change the descriptions of plant-based
food on menus and packaging to evoke taste
and indulgence, like “spicy chickpea curry” and“pasta with creamy sauce”.17 Avoid terms like“vegetarian” and “meat-free” that can have negative
connotations, implying to some people that plantbased food is lacking substance or flavour.
Who might be involved? Campus catering
coordinators

Harness positivity and pride
How? Campaign with a message of positivity,
avoiding a tone of guilt or admonishment.
For example, tap into people’s sense of group
identity and belonging to their university tofoster pride in the campus’s beauty and naturalareas, and ultimately promote engagement withenvironmental issues.
Who might be involved? Campus sustainability
coordinators, student sustainability groups,
university administration

Create social opportunities for sharing
and reuse
How? Hold events such as repair cafés and set
up networks for activities such as ride-sharing.
Promote these as social occasions and ways
for budget-conscious students to save money,
rather than solely as pro-environmental causes.
Who might be involved? Campus sustainability
coordinators, student sustainability groups
Students at the University of Ghana.
The Little Book of Green Nudges 19

MAKE IT ATTRACTIVE
Use smart incentives
The nudge: People can be motivated by financial rewards
and savings, including “gamified” monetary incentives suchas lotteries or competitions. They can also be encouraged
towards sustainable behaviour by non-monetary incentives,
such as public recognition.
Evidence that it’s effective: People in the US who playeda game competing with others to be more sustainableconsumed less energy for several months after playing thegame.18

Why it works: Lotteries can be effective motivators
because people often focus on a large prize, even if theirchance of winning it is small. Non-financial incentives canwork because social approval or recognition can be just as
motivating as money (see the “Make It Social” section tofollow). Also, if there is a risk of payment displacing people’s
intrinsic motivation to do the right thing, non-monetary
rewards and social recognition can be more effective.

Encourage
people tobring their own
mug by charging
extra fordisposable
cups

Charge for not using your own coffee mug
How? Instead of providing a discount forbringing a reusable mug to campus coffee
shops, harness loss aversion by adding a fee
for using disposable cups.
Who might be involved? Campus catering
coordinators

20 The Little Book of Green Nudges

offerpromotional
deals thatencourage
sustainablechoices

Introduce lottery-based deposit
return schemes

Promote sustainable “meal deal”
incentives

Publicly display sustainability
ratings

How? In campus cafeterias and shops, offer
promotional deals that encourage sustainablechoices. For example, have daily specials be
plant-based, or offer a free drink to diners
who choose a plant-based main course. (But
to prevent food waste, avoid promotions thatencourage people to get more food than theyneed, such as offering a free side dish alongsidea sustainable main course.)

How? Put displays in cafeteria windows to show
how much food waste has been reduced, or in
public areas of residence halls to show how
much energy has been saved. This can be asocial, non-financial incentive, making people
feel like they are gaining status through a groupeffort, or it can stimulate a sense of competition
between residence halls to save the most energy
or recycle the most waste.

Who might be involved? Campus catering
coordinators

Who might be involved? Campus sustainability
coordinators, campus catering coordinators,
campus building managers

How? Most deposit return programs charge
customers a small fee when they purchaseplastic, glass or aluminium drink containers,
then refund it when the container is returned.
Instead, make container return more attractiveby having the deposit provide entry into alottery with large and appealing prizes. The total
amount of money paid out can be the same.
Who might be involved? University
administrators

CASE STUDYAt Universidad de la Costa, Colombia,
students and staff received a small gift,
such as a pen or keychain, in exchange
for bringing in recyclable material over acertain weight.

The Little Book of Green Nudges 21

MAKE IT SOCIAL
Highlight others’
sustainable behaviour
The nudge: Publicize the fact that many people are alreadyadopting a green behaviour.
Evidence that it’s effective: High-consuming electricity
customers in the US decreased their usage after receiving
reports comparing them to their more efficient neighbours(and low-consuming customers stayed low when given
positive feedback in the form of a smiley face).19 People
were more interested in cutting down their meat consumption
when they were informed that a growing number of people
had recently started eating less meat.20

Why it works: People are highly influenced by what others
are doing, so we’re more likely to adopt a behaviour when we
think that the majority of people do it or an increasing numberof people are shifting towards it.

Share information about positive trends
How? If a desired sustainable behaviour isperformed by a growing minority, publicize thatfact. For example, highlight that more and more
people are eating plant-based foods or using
reusable cups.21
Who might be involved? Campus catering
coordinators, campus sustainability
coordinators, student sustainability groups

22 The Little Book of Green Nudges

Provide social comparisons of energy
and water use

Publicize university rankings that measuresustainability

How? Send messages to individuals letting themknow whether they consume more energy orwater than others, or publish a list ranking users
by their consumption. This approach tends tobe more effective when comparing individual
people rather than groups.

How? Build engagement among university staff
by highlighting how campus sustainability
initiatives are taken into account in many
university league tables or rankings, making
sustainability a status symbol and tapping into
competitive instincts.

Who might be involved? Campus building
managers

Who might be involved? University
administrators

CASE STUDYThe University of Bath, UK, logged shower
duration in campus residences, and used
the information in social norm messages.
They found that students who were told
they took longer-than-average showers
decreased their shower time. But they also
noted that those who were told they took
shorter-than-average showers increased
their shower time.

CASE STUDYThe University of California, Davis, US, hasa green workplace certification programme
to give public recognition to sustainableoffices and labs on campus.

CASE STUDY
Karatina University, Kenya, which recently
branded itself as a “Green University”,
has established a Green Innovations
competition week, where teams ofstudents submit projects that addressenvironmental issues through social andtechnological innovations, with prizes forthe winning teams.

The Little Book of Green Nudges 23

MAKE IT SOCIAL
Harness identity andthe right messengers
The nudge: Use messaging that focuses on a positivesocial identity or implies that the recipient’s social group
includes people who perform a desired behaviour. Send
messages from people the recipient is likely to respect oridentify with.
Evidence that it’s effective: A campaign to reduce
illegal wildlife trade among men in Vietnam highlighted
the desirable identity of internal character strength(“chi”), contrasted with obtaining strength from rhino horn
consumption.22 Students from disadvantaged backgrounds
in the UK were more likely to apply to university when theyreceived a letter of encouragement from a former studentwith a similar background.23

Why it works: People attach a lot of value to their senseof identity and to social groups they belong to or want tobelong to. Social influences are particularly powerful when
they come from “people like us”, or people we find likeable,credible or authoritative.

24 The Little Book of Green Nudges

Student activists at Cyprus University of Technology.

Broaden messages to appeal to awide audience

Choose messengers who will bereceived positively

Highlight desirable
identities

How? When promoting positive behaviours, avoid
terms associated with narrow identities that
could make people feel excluded. For example,
avoid words such as “vegetarian” or “vegan”
to describe food on menus (try “field-grown”
instead),24 and don’t frame bicycling as anactivity done by “cyclists”, as this may alienate
certain groups, including some women.25

How? In messaging campaigns, make surethe sender is someone the recipient identifies
with or is likely to feel positively about. For astudent audience, appropriate messengers
could be fellow students or former students,
especially if they are well known. Ensuringthat characteristics of messengers reflect thetarget audience (for example, in terms of gender,
ethnicity and age) is key to appeal to different
parts of the populace.

How? Frame campaigns in terms of identities
that people aspire to or groups they belong
to. For example, the “Don’t mess with Texas!”
messaging campaign in the US reduced litterby harnessing a group identity that Texans areproud of.

Who might be involved? University
administrators, campus sustainability
coordinators, student sustainability groups,
campus catering managers

Who might be involved? Campus sustainability
coordinators, student sustainability groups

Who might be involved? Campus sustainability
coordinators, student sustainability groups
The Little Book of Green Nudges 25

MAKE IT SOCIAL
Use social connections
and peer pressure
The nudge: Encourage people to make public commitments tosustainability and reach out to others in their social networks.
Encourage groups to take action together, such as sports
teams, university departments and halls of residence. Highlight
opportunities for people to help each other.

Create opportunities to makepublic pledges
How? Encourage staff and students to makepledges towards sustainable goals in front ofpeers. Suitable moments could be when new
employees join the university, when students
move into residence halls, or when students joinmembership clubs.
Who might be involved? Campus sustainability
coordinators, student sustainability groups

Evidence that it’s effective: A message about helping others
increased the number of people signing up to be organ donors in
the UK by 35 per cent compared to a control message.26

Why it works: Feeling a responsibility to do something “for”
someone else can be a strong motivator. This can involvecommitments made to another person or in public (people wantto avoid the social cost of not following through), influence frompeers and others in our social networks, and reciprocity (people
feel obliged to do something in return for someone who has done
something for them).

Student activists at Universidad Nacional Pedro Henríquez Ureña in the
Dominican Republic.
26 The Little Book of Green Nudges

Incentivize
students
to bring afriend tosustainability
eventsCASE STUDY

Provide incentives to encourage
peer referral

Distribute and share
leftovers

How? When holding sustainability events on
campus, build support and engagement bygiving attendees a small perk if they bring along
a friend.

How? Reduce food waste by tapping into
people’s social networks and desire to help
others. Facilitate giving away leftover food bysetting up a campus-wide food-sharing group, or
encouraging sign-ups to an existing food-sharing
app. Encourage campus cafeterias and foodshops to give away leftovers or sell them cheaply,
or use an existing app that facilitates this.

Who might be involved? Campus sustainability
coordinators, student sustainability groups

Who might be involved? Campus sustainability
coordinators, student sustainability groups,
campus catering coordinators

Five students at Aalto University, Finland,
set up a food-sharing group that enables
distribution of leftovers on campus,
such as from meetings and parties, forfree. They were mentored by the Aalto
Ventures Program during its flagship“start-up experience” course, and started
their initiative by collecting and analysing
kitchen waste on campus to gain insight
into what food was being thrown away.
They set up the food-sharing group without
any funding, and all marketing happened
via word of mouth. The founders thought
the biggest barrier was encouraging theinitial members to join, but now they havea growing membership of more than 1,000
people. So far, the group has prevented
more than 7,000 kilograms of food fromgoing to waste. Their tips for success are
to reach out to supermarkets, restaurants
and student associations on campus
and ask them to share leftovers, and to
regularly seek feedback from users.

The Little Book of Green Nudges 27

MAKE IT TIMELY
Encourage pre-commitments
and emphasize present
benefits
The nudge: Ask people to commit ahead of time to a sustainable action andmake small changes at first. Highlight benefits of sustainable behaviour that canbe experienced in the short term.
Evidence that it’s effective: Hotel guests were more likely to reuse towels
when they committed to do so at check-in.27 Consumers were more willing to buy
energy-efficient washer-dryers when given information at the point of purchaseabout the lifetime running costs, as this made the future savings more salientin the short term, offsetting the higher immediate purchase costs of efficient
appliances.28

Why it works: The complexities of life and our limited willpower often get in theway of our good intentions. We are therefore more likely to act on those intentions
if we lock ourselves into a commitment in advance, such as signing up to run amarathon. We feel more strongly about consequences that are more immediate,
so we are more likely to follow through if the benefits are emphasized in thepresent and the costs are pushed into the future.

Encourage pre-ordering of catered meals
How? In catered halls of residence and atuniversity events, ask attendees to choose
food in advance, when immediate gratification
is not an issue and people tend to favour longterm intentions for being healthier and moresustainable. This could be combined with othernudges towards plant-based food.
Who might be involved? Campus catering
coordinators, catering companies

28 The Little Book of Green Nudges

Ask people to pre-commit to gradualchanges

Offer interest-free loans for public
transport passes

How? Rather than pushing people to make largechanges to their behaviour, ask them to commit
to making cumulative small changes. For
example, they could start by cycling to campus
one day per week this term, and increase to twodays per week next term, and so on.

How? Make the financial benefits of public
transport more immediate by providing interestfree loans for students and staff to buy season
passes or tickets. Once people have boughta season pass, they will be more likely to use
public transport.

Who might be involved? Campus sustainability
coordinators, student sustainability groups

Who might be involved? University
administrators

The Little Book of Green Nudges 29

MAKE IT TIMELY
Harness or create timely
moments
The nudge: Run communication campaigns and events at times whenpeople are forming new routines, such as the beginning of term. Create
special occasions for collective action, such as “Cycle to Campus Week”.
Evidence that it’s effective: People were four times more likely tosign up to a new bike-sharing scheme when they had recently moved
into the area (because they were forming new routines in their lives)compared to when existing residents just had a bike docking station
installed near their home.29

Why it works: Humans are creatures of habit and it can be difficult tochange our behaviour once we’ve gotten into a routine, but you cancapitalize on or generate moments of disruption to help people start new
habits. For example, encourage changes when someone moves house, or
get people to try something new during a dedicated day, week or month.

Help newcomers form sustainable habits
How? Provide tips on sustainable food choices
to first-year students, who may be shoppingand cooking for themselves for the first time.
Give new staff and students tips on sustainable
travel to and around campus, such as transport
information and maps of good bicycle routes.
Who might be involved? Campus sustainability
coordinators, student sustainability groups, HR
department

30 The Little Book of Green Nudges

CASE STUDYReduce waste at the end of term

Hold campus-wide moments of action

How? Provide locations or hold events wherestudents can donate or sell textbooks when
they have finished classes, or give away
household items when they are moving outof accommodation. The university or student
groups could sell these items the following term.

How? Arrange times for collective action, suchas an energy-tariff switching day for students
living in their own accommodation. Introduce
short-term campus-wide changes, such as asking
people to cycle to campus one day each month, orencouraging people to eat plant-based food during
one week, to build support for larger change.

Who might be involved? Campus sustainability
coordinators, student sustainability groups,
campus store managers

Who might be involved? Campus sustainability
coordinators, student sustainability groups,
campus catering coordinators

The Universidad Tecnológica de Pereira,Colombia, holds mass waste collection
days four times a year, which also involvecommunity members in raising awarenessabout reducing waste.

CASE STUDYThe University of British Columbia, Canada,
runs a “Seasonal Shutdown” campaign,encouraging campus department buildings
to turn off and unplug electronics during thewinter break. This includes the additional
nudge of providing a checklist (see “Provide
checklists” section on the following page).

The Little Book of Green Nudges 31

MAKE IT TIMELY
Help people plan andfollow throughThe nudge: Provide people with simple tips about specificsmall behaviour changes they could make, and ask them toplan out the steps they will take along the way.
Evidence that it’s effective: When employees planned
their recycling intentions, a company produced less waste
going to landfill.30

Why it works: We’re more likely to act on our intentions
when we have a specific plan with concrete actions andsteps to overcome potential barriers. Simple guidelines andrules of thumb can also keep us on track, as can prompts
or reminders at key moments and feedback on the positiveeffects of our behaviour.

Provide checklists
How? In student accommodation, provide stepby-step checklists to help residents make moresustainable decisions: for example, how to use
leftover food and avoid food waste, how to obtainsecondhand or shared items on campus, andhow to reduce energy consumption at home.
Who might be involved? Campus sustainability
coordinators, student sustainability groups,
campus building managers

32 The Little Book of Green Nudges

Holdevents atwhich people
can get theirbikes fixed for use
the following
term

Support people before they need it

Help people follow through on saving energy

How? Hold events at which people can get theirbikes fixed for use the following term, helping
them plan ahead and be ready to cycle in the
future.

How? As part of an energy-saving campaign toencourage people to turn off computer monitors
and unplug chargers, help people follow throughby putting reminder messages on computersand powerstrips to highlight the costs ofwasting electricity.

Who might be involved? Campus sustainability
coordinators, student sustainability groups,
technical staff

Who might be involved? Campus building
managers

CASE STUDYThe University of Copenhagen, Denmark,created a nudge to reduce heating loss
from open windows by hanging turnablecards on them, with a red side to remind
people to close windows and a green side
to show when windows have been closed.

The Little Book of Green Nudges 33

Five steps to make your nudge a success
Many of the nudges in this book could be lifted right from the page and implemented on your campus.
But if you want to increase your odds of success by tailoring the nudges to address a specific issue on
your campus, follow this five-step process.

your
1 Choosetarget behaviour
Be specific: Nudges are more effective
when they target a specific behaviour anda specific audience. Instead of “Promote
more sustainable food choices among
students”, a better target could be “Reduce
red meat consumption by students in campus
cafeterias”. Remember to target an action, notan attitude or awareness.
Look for quick wins: Some behaviours are
difficult to change because they are dictatedmostly by cost or structural barriers, such as
deciding whether to insulate campus buildings
to conserve energy. These are important toconsider, but the power of nudges is often
in achieving impact where behaviours are
more malleable, such as switching off lights,
recycling or choosing different foods.

34 The Little Book of Green Nudges

Aim for impact: Some behaviours have moreof an impact on the environment than others.
For example, preventing unsustainableconsumption (e.g. reducing single-use plastics)
is generally better than trying to mitigate its
effects (e.g. encouraging recycling). Try to
focus on behaviour change that will make thebiggest difference.

2

Understandyour context

Consider factors that affect human behaviour:
It’s useful to think about three levels:31• The individual level: What conscious
motivations, attitudes and knowledge doindividuals have? And how do non-conscious
biases, habits and emotions influence them?
• The social level: How is our behaviour shapedby cultural norms, identities, relationships
and interactions with other people?
• The material level: What is the wider context
of the behaviour? What are the constraints
or incentives set by economic factors,
infrastructure, technology and availability ofoptions?
Identify barriers to behaviour change: Consider
which of the individual, social and material
influences may make it difficult for people toadopt your target behaviour. For example, ifbuying green products is considered “feminine”,
then cultural norms (a social influence) could
be a barrier to encouraging environmentally
responsible consumption.32
Identify drivers of behaviour change: Consider
which of the individual, social and material
influences may facilitate the behaviour you
want to encourage. For example, if students areon a tight budget, then a need to save money (amaterial influence) could be harnessed to help
reduce food waste.

Look for touchpoints for intervention: Given
these barriers and drivers, where and when
could you intervene to change behaviour on
campus?
• What are the moments of decision for yourtarget audience? For food waste, this could
be when buying food at a campus cafeteria or
when deciding what to throw out of a fridgein a student kitchen.
• What points of influence do you have overyour target audience? For example, you havemore influence over what students buy at a
campus cafeteria than at a supermarket.
• What channels of communication or contact
do you have with your target audience? These
could include posters on campus or a regular
end-of-term email to staff, but could also
include changing the choice environment inwhich a student buys their groceries.
Reassess and finalize your target: In answering
these questions, do you still believe you havechosen the best target behaviour, one thatgives you an opportunity to maximize impact
and feasibility? If not, consider other targets
and repeat steps 1 and 2.

The Little Book of Green Nudges 35

3

DESIGNYOUR NUDGE

Now that you have a specific target behaviour
and an understanding of the context, pick a
type of nudge from the EAST categories that is
likely to address the barriers you identified andharness the potential drivers.
Consider what will be most effective: For
example, you are likely to save more paper by

36 The Little Book of Green Nudges

setting printers to default to double-sided mode
than by reminding people to print double-sided.
Choose a nudge that you can realistically put
into action: For example, it might be difficult tochange the road infrastructure on campus, buteasier to paint coloured cycle lanes on the roads
to make them more inviting for people on bikes.

Involve the right people: Find out who on campus
is responsible for any processes or systems yournudge will change. Ensure you engage them inthe process so you can overcome institutional
hurdles. (The campus catering coordinator, forexample, can be a critical ally.) Agree who is
responsible for each component of implementing
your nudge and assign each person specifictasks with clear timelines.
Build support on campus: Reach out to keygroups or individuals, such as the student
union or campus sustainability coordinator, to

let them know what you’re planning and why,
and to solicit their feedback. They could help
your nudge gain acceptance and have greater
impact. Make sure to include people fromdifferent groups in your outreach, including
people of different genders and backgrounds.
Recognize people who might be negatively
affected: For example, if your nudge aims todiscourage driving, how might it affect those who
are unable to walk or cycle, or who are more at
risk when using public transport? What measures
could be put in place to support them?

CASE STUDY: OVERCOMING BARRIERSAt the University of California, Berkeley,
US, students in the Housing & Dining
Sustainability Advocates group foundthat the main barrier they face is findingtime with the appropriate campus staff toapprove changes such as rearranging bins,
hanging up new signs or using different
products. Their tip is to build relationships
with others on campus, including facilities
managers, dining managers, chefs,
custodians and campus administrators.
They found that when they shared theirgoals, others on campus were more likely
to support them.

The Little Book of Green Nudges 37

4

Test the effectivenessof your nudge

Trial before you roll out on a large scale: It’s
easy to assume that a nudge will be effective,
but even if you have good reason to believe so,this may not be the case in practice. Test out
your intervention on a small scale to see how
well it works.
Measure outcomes: How could you measure
your target behaviour? Direct observation, suchas recording sales of plant-based dishes in a
campus cafeteria, is generally more reliable
than indirect reports, such as asking people ina survey what they ate for lunch.

Compare outcomes: How would you knowthat a change in the target behaviour is due
to your nudge? You’ll need to compare theoutcomes of people who experienced thenudge and those who didn’t. For example,
some halls of residence could be randomly
allocated to receive messages about reducing
energy consumption while others receive nonudging messages.
Watch for knock-on effects: Might there beunintended consequences of your nudge, either
positive or negative? On one hand, our attitudes

CASE STUDIES: TRIALLING YOUR NUDGE
Yale University, US, implemented a nudge
to increase recycling and reduce waste
in campus buildings, and trialled it byassigning buildings to different test groups.
Buildings in the first group received amonthly statement showing a monetary
cost associated with the amount of waste
generated, those in the second group
received a statement plus tips for reducing
waste, and those in the third group (including

38 The Little Book of Green Nudges

only the undergraduate residential colleges)
were entered into a recycling competition. Overfour months, there was a decrease in waste
production in all three groups, and an increase inrecycling in the second and third groups.
HEC Paris made cigarette-disposal bins more
eye-catching by adding a basketball hoopon one bin and a “voting box” on anotherwhere students could show their support

for a humorous cause by throwing in acigarette butt. They tested this initiativeby measuring the number of cigarettebutts discarded on the ground before andafter the nudge was implemented, and bycomparing the areas with eye-catchingbins to control areas with standard bins.
They found that the number of discarded
cigarettes decreased by over a third in thenudge areas.

CASE STUDIES: UNINTENDEDCONSEQUENCES
When the University of Hong Kong
stopped the use of some disposable
plastic items on campus, there was
reduced consumption of these items
but also a partial switch to different
disposable items such as paper
containers. To tackle this, the university
is encouraging staff and students toadopt bring-your-own habits, including
discounts for people who use their own
containers at campus catering outlets,
and a “BYO week” in collaboration withall other universities in Hong Kong.

often shift to match our behaviour, so nudges
to change behaviour can help build support forengagement. On the other hand, if we substitute a
new behaviour for the old one, that new behaviour
might have undesirable effects (see case studies).
Consider the whole population: Might certain
parts of the population be affected differently
by your nudge? Make sure to check the outcomesfor people of different genders, cultures andother groups.

The Technical University of Denmark
introduced meat-free days in campus
canteens. But then it found that more
people ate at street food stalls on campusthat sold meat, which had the additional
consequence of greater use of single-use
packaging and cutlery. In response, thecanteens changed the nudge to featureless meat rather than no meat. Canteen
sales returned to their previous levels,
so this adjustment appears to havebrought customers back.

Students at the University of Hong Kong fill up theirreusable containers.

The Little Book of Green Nudges 39

5

Reflect andredesign

Build on success: Was your nudge effective? If
so, don’t stop here!
• Refine your nudge with small changes basedon what worked best in your trial. For example,
in a nudge involving messaging, take anotherlook at the messages you found to have thegreatest impact and consider ways to makethem even better, or make them more effective
among different gender and cultural groups.
Then test your nudge again.
• Roll out your nudge more widely
across campus. What resources andfurther support might you need?

40 The Little Book of Green Nudges

Or reassess: Perhaps your nudge didn’t work as
you thought it would. This often happens thefirst time you trial something. Implementing aneffective nudge is an ongoing process, which
can take more than one round of designing andtesting. What did you learn from your trial thatyou could apply as you go forward?

• Did you run into any logistical issues that

limited your nudge? For example, perhaps
you were not able to hold as many repair café
events as you had intended.
• Did people not pay attention to your nudge?
For example, perhaps you held many repair
café events but attendance was low. If
so, can you get feedback from your target
audience that might tell you why?

Checklist for successful nudges
1. Choose your target behaviour• What is the specific target behaviour you want
to change?
e.g. reducing red meat consumption on campus
Who
is your specific target audience?
•e.g. first-year students
2. Understand your context• What individual influences on behaviour might
be barriers or drivers?
e.g. students lack cooking skills andexperience planning grocery shopping• What social influences on behaviour might bebarriers or drivers?
e.g. social norms of eating meat
• What material influences on behaviour might
be barriers or drivers?
e.g. contract with catering company• What are the touchpoints where you could
intervene to change behaviour?
e.g. campus cafeterias

4. Test the effectiveness of your nudge• What behavioural outcome will you measure?
e.g. number of meat dishes sold per day incafeteria for the whole termWhatis your comparison to know if your nudge•
worked?
e.g. record sales of meat dishes for a term
before the nudge, or record in anothercafeteria without the nudge
5. Reflect and redesign• How could you improve your nudge?
e.g. next time redesign the menu to featureplant-based dishes more prominently

3. Design your nudge• What is your nudge?
e.g. change descriptions of food on menus
Whatresources will you need?
•e.g. time and creativity to brainstorm newmenu descriptions (no cost for printing menus
compared to business as usual)Whosebuy-in do you need in order to•implement your nudge?
e.g. campus catering manager
The Little Book of Green Nudges 41

ENDNOTES
1. National Union of Students (2019). Sustainability
Skills Survey 2018-19. Available at https://nusdigital.s3-eu-west-1.amazonaws.com/document/
documents/50229/7c736d65da810a6c9e39df10c9a0e455/20191004_NUS_Sustainability_Skills_2018-19_
FINAL.pdf
2. Princeton Review (2020). 2020 College Hopes & Worries
Survey Report. Available at https://www.princetonreview.
com/college-rankings/college-hopes-worries
3. Institute for Global Environmental Strategies, Aalto
University and D-mat ltd. (2019). 1.5-Degree Lifestyles:
Targets and Options for Reducing Lifestyle Carbon
Footprints. Hayama, Japan: Institute for Global
Environmental Strategies. Available at https://www.
iges.or.jp/en/pub/15-degrees-lifestyles-2019/en
4. BBMG, GlobeScan and SustainAbility (2012).
Re:Thinking Consumption: Consumers and the
Future of Sustainability. Available at http://
theregenerationroadmap.com/files/reports/TRR_
Rethinking_Consumption.pdf
5. University of Cambridge website. The Cambridge Green
Challenge: Environment and Energy. Accessed on 13
July 2020 at https://www.environment.admin.cam.
ac.uk/facts-figures
6. The Behavioural Insights Team (2014). EAST: Four
Simple Ways to Apply Behavioural Insights. London.
Available at https://www.bi.team/publications/eastfour-simple-ways-to-apply-behavioural-insights/
7. Ebeling, Felix, and Sebastian Lotz (2015). Domestic
Uptake of Green Energy Promoted by Opt-out Tariffs.
Nature Climate Change, vol. 5 (September), pp. 868-871.
Available at https://doi.org/10.1038/nclimate2681
8. Egebark, Johan, and Mathias Ekstroöm (2016). Can
Indifference Make the World Greener? Journal of
42 The Little Book of Green Nudges

Environmental Economics and Management, vol. 76(March), pp. 1-13. Available at https://doi.org/10.1016/j.
jeem.2015.11.004
9. Duffy, Sean, and Michelle Verges (2008). It Matters a
Hole Lot: Perceptual Affordances of Waste Containers
Influence Recycling Compliance. Environment andBehavior, vol. 41, No. 5, pp. 741-749. Available athttps://doi.org/10.1177/0013916508323737
10. Thiagarajah, Krisha, and Victoria M. Getty (2013).
Impact on Plate Waste of Switching from a Tray to a
Trayless Delivery System in a University Dining Halland Employee Response to the Switch. Journal of the
Academy of Nutrition and Dietetics, vol. 113, No. 1,
pp. 141-145. Available at https://doi.org/10.1016/j.
jand.2012.07.004
11. Kurz, Verena (2018). Nudging to Reduce Meat
Consumption: Immediate and Persistent Effects ofan Intervention at a University Restaurant. Journalof Environmental Economics and Management,
vol. 90 (July), pp. 317-341. Available at https://doi.
org/10.1016/j.jeem.2018.06.005
12. Garnett, Emma E., and others (2019). Impact ofIncreasing Vegetarian Availability on Meal Selectionand Sales in Cafeterias. Proceedings of the National
Academy of Sciences, vol. 116, No. 42, pp. 2092320929. Available at https://doi.org/10.1073/
pnas.1907207116
13. Scannell, Leila, and Robert Gifford (2011). Personally
Relevant Climate Change: The Role of Place Attachment
and Local Versus Global Message Framing in
Engagement. Environment and Behavior, vol. 45, pp. 60-85.
Available at https://doi.org/10.1177/0013916511421196
14. iNudgeyou website. Green Nudge: Nudging Litter into
the Bin. Accessed on 13 July 2020 at https://inudgeyou.
com/en/green-nudge-nudging-litter-into-the-bin/

15. Howell, Rachel A. (2013). It’s Not (Just) ‘‘theEnvironment, Stupid!’’ Values, Motivations, and Routes
to Engagement of People Adopting Lower-Carbon
Lifestyles. Global Environmental Change, vol. 23,
pp. 281-290. Available at https://doi.org/10.1016/j.
gloenvcha.2012.10.015
16. Schneider, Claudia R., and others (2017). The Influenceof Anticipated Pride and Guilt on Pro-Environmental
Decision Making. PLoS ONE, vol. 12, No. 11. Available athttps://doi.org/10.1371/journal.pone.0188781
17. Turnwald, Bradley P., Danielle Z. Boles and Alia J. Crum(2017). Association Between Indulgent Descriptions
and Vegetable Consumption: Twisted Carrots andDynamite Beets. JAMA Internal Medicine, vol. 177, No.
8, pp. 1216-1218. Available at https://doi.org/10.1001/
jamainternmed.2017.1637
18. Ro, Michael, and others (2017). Making Cool Choices
for Sustainability: Testing the Effectiveness of a GameBased Approach to Promoting Pro-Environmental
Behaviors. Journal of Environmental Psychology, vol.
53, pp. 20-30. Available at https://doi.org/10.1016/j.
jenvp.2017.06.007
19. Rabison, Rebecca (2019). The Truths About Opower
Smiley Faces. Oracle Utilities Blog. Accessed on 13 July
2020 at https://blogs.oracle.com/utilities/the-truthsabout-opower-smiley-faces
20. Sparkman, Gregg, and Gregory M. Walton (2017).
Dynamic Norms Promote Sustainable Behavior, Even
if It Is Counternormative. Psychological Science, vol.
28, No. 11, pp. 1663-1674. Available at https://doi.
org/10.1177/0956797617719950
21. Loschelder, David D., and others (2019). Dynamic
Norms Drive Sustainable Consumption: Norm-Based
Nudging Helps Café Customers to Avoid Disposable
to-Go-Cups. Journal of Economic Psychology, vol. 75,

(A), No. 102146. Available at https://doi.org/10.1016/j.
joep.2019.02.002
22. Willemsen, Madelon, and Trinh Nguyen (2017). Chi
Briefing Paper: Providing Insights of the Impact of a
Behaviour Change Campaign to Reduce the Demandfor Rhino Horn in Viet Nam. Available at http://dx.doi.
org/10.13140/RG.2.2.18724.37761
23. The Behavioural Insights Team (2017). Encouraging
People into University: Research Report. London. Available
at https://www.bi.team/wp-content/uploads/2017/03/
Encouraging_people_into_university.pdf
24. Vennard, Daniel, Toby Park and Sophie Attwood(2018). Encouraging Sustainable Food Consumption
by Using More-Appetizing Language: Technical Note.
Washington, D.C.: World Resources Institute. Available
at https://www.wri.org/publication/encouragingsustainable-food-consumption-using-more-appetizinglanguage
25. Motherwell, Suzanne (2018). “Are We Nearly There
Yet?” Exploring Gender and Active Travel. Bristol, UK:
Sustrans. Available at https://www.sustrans.org.uk/
media/2879/2879.pdf
26. Sallis, Anna, Hugo Harper and Michael Sanders (2018).
Effect of Persuasive Messages on National HealthService Organ Donor Registrations: A Pragmatic QuasiRandomised Controlled Trial with One Million UK Road
Taxpayers. Trials, vol. 19, No. 513. Available at https://www.doi.org/10.1186/s13063-018-2855-5

DECC/John Lewis Energy Labelling Trial. London:
Department of Energy and Climate Change. Available athttps://assets.publishing.service.gov.uk/government/
uploads/system/uploads/attachment_data/
file/350282/John_Lewis_trial_report_010914FINAL.pdf
29. Kirkman, Elspeth (2019). Free Riding or Discounted
Riding? How the Framing of a Bike Share Offer Impacts
Offer-Redemption. Journal of Behavioral Public
Administration, vol. 2, No. 2, pp. 1-10. Available athttps://doi.org/10.30636/jbpa.22.83
30. Holland, Rob W., Henk Aarts and Daan Langendam(2006). Breaking and Creating Habits on the
Working Floor: A Field-Experiment on the Power of
Implementation Intentions. Journal of Experimental
Social Psychology, vol. 42, pp. 776-783. Available athttps://doi.org/10.1016/j.jesp.2005.11.006
31. Scottish Government (2013). The ISM Tool website.
A Practical Tool for Designing Effective Policy
Interventions. Accessed on 13 July 2020 at https://www.ismtool.org/
32. Brough, Aaron R., and others (2016). Is Eco-Friendly
Unmanly? The Green-Feminine Stereotype and Its Effecton Sustainable Consumption. Journal of Consumer
Research, vol. 43, No. 4, pp. 567–582. Available athttps://doi.org/10.1093/jcr/ucw044

27. Baca-Motes, Katie, and others (2013). Commitment
and Behavior Change: Evidence from the Field. Journalof Consumer Research, vol. 39, No. 5, pp. 1070-1084.
Available at https://doi.org/10.1086/667226
28. Department of Energy and Climate Change and the
Behavioural Insights Team (2014). Evaluation of the
The Little Book of Green Nudges 43

Resources and references
Visit unep.org/nudges for more information or to get yourcampus involved in a nudging campaign.
Further reading
The Behavioural Insights Team (2014). EAST: Four Simple
Ways to Apply Behavioural Insights. London. Available athttps://www.bi.team/publications/east-four-simple-waysto-apply-behavioural-insights/

The Behavioural Insights Team (2020). A Menu for
Change: Using Behavioural Science to Promote
Sustainable Diets Around the World. London. Available
at https://www.bi.team/wp-content/uploads/2020/03/
BIT_Report_A-Menu-for-Change_Webversion_2020.pdf.pdf
Hansen, Pelle Guldborg (2019). Nudging: To Know “WhatWorks” You Need to Know Why It Works. Journal of Behavioral
Economics for Policy, vol. 3 (Special Issue), pp. 9-11.

Available at https://sabeconomics.org/wordpress/wpcontent/uploads/JBEP-3-S-1.pdf
Haynes, Laura, and others (2013). Test, Learn, Adapt:
Developing Public Policy with Randomised Controlled
Trials. London: The Behavioural Insights Team. Available
at https://www.bi.team/wp-content/uploads/2013/06/TLA1906126.pdf
United Nations Environment Programme (2015). Gender
Equality and Environment: Policy and Strategies.
Available at https://wedocs.unep.org/bitstream/
handle/20.500.11822/7655/-Gender_equality_and_the_environment_Policy_and_strategy-2015Gender_equality_
and_the_environment_policy_and_strategy.pdf.pdf
United Nations Environment Programme (2016).
Fostering and Communicating Sustainable Lifestyles:
Principles and Emerging Practices. Available at https://www.oneplanetnetwork.org/resource/fostering-andcommunicating-sustainable-lifestyles-principles-andemerging-practices-full
United Nations Environment Programme and One Earth(2018). Sustainable Lifestyles: Options and Opportunities.
Paris: United Nations Environment Programme. Available
at https://www.oneplanetnetwork.org/resource/
sustainable-lifestyles-options-and-opportunities

44 The Little Book of Green Nudges

PHOTO CREDITS

Featured universities

pg. 12: Milla Uusitalo/Aalto University
pg. 13: University College Corkpg. 17: Tongji University
pg. 19: Dominic Chavez/World Bankpg. 24: Cyprus University of Technology
pg. 26: Universidad Nacional Pedro Henríquez Ureña
pg. 30: Mike/Flickr
pg. 37: Michael Puche/iStockphotopg. 39: HKU Sustainability Office

Aalto University (Finland)
Cyprus University of Technology (Cyprus)
Dalhousie University (Canada)
HEC Paris (France)
Karatina University (Kenya)
Mahidol University (Thailand)
Portland Community College (US)Technical University of Denmark (Denmark)Tongji University (China)
Universidad de la Costa (Colombia)
Universidad Nacional Pedro Henríquez Ureña (Dominican Republic)
Universidad Tecnológica de Pereira (Colombia)
University College Cork (Ireland)
University of Bath (UK)
University of British Columbia (Canada)
University of California, Berkeley (US)University of California, Davis (US)University of Copenhagen (Denmark)
University of Hong Kong (China)
University of Malta (Malta)
University of St Andrews (UK)
University of Winchester (UK)
Yale University (US)The Little Book of Green Nudges 45

GREEN NUDGES AT A GLANCE
Here’s a simple summary of the EAST subcategories and sample nudges in each one.

Make sustainability

Make sustainability

Make sustainability

Make sustainability• Use defaults.

• Draw attention.

• Highlight others’ sustainable• Encourage pre-commitments• Harness identity and the right• Harness or create timely moments.

EASY

Example: Give guests at catered
events the most sustainable
food option unless they request
otherwise.

• Remove or add frictions.
Example: Offer smaller plates andno trays in campus canteens.
• Change the choice environment.

Example: Provide fewer carparking spaces and more bikeparking spaces.

46 The Little Book of Green Nudges

aTTRACTIVE
Example: Design recycling bins tobe eye-catching.

• Frame messages positively andhighlight co-benefits.
Example: Promote sustainable
food as tasty and indulgent.

• Use smart incentives.

Example: Introduce lottery-based
deposit return schemes forrecyclable items.

SOCIALbehaviour.
Example: Compare university
departments’ energy use to eachother.

messengers.
Example: Spread messages via
people with whom students
identify.

• Use social connections and peerpressure.
Example: Set up a food-sharing
group to distribute leftovers on
campus.

TIMELYand emphasize present benefits.
Example: Provide interest-freeloans to help students buy public
transport passes.

Example: Give first-year students
tips for sustainable food shopping.

• Help people plan and follow

through.
Example: Provide a checklist for
reducing water use in student
halls.

Which green nudges will you use?
Now it’s over to you. You can use the EAST principles not only to design nudges but also to help you follow through with your intentions to implement them.
Write down your plans for green nudging, starting by answering the questions on this page.

My plans for green nudging on campus
What I will do:

The specific steps I will need to take:

When I will take the first step:

Who I will involve in the process:

What difference I want to make:

To whom I will commit to doing this:The Little Book of Green Nudges 47

Behavioural science shows that simple “nudges” towards everyday greener decisions can help people
develop sustainable habits and live more in line with their environmental values. Nudging can beparticularly powerful at higher education institutions. Examples:• Eliminate trays in cafeterias to reduce food waste• Use appealing descriptions for plant-based dishes• Make recycling bins eye-catching and easy to use• Provide more spaces for parking bicycles and fewer for parking cars
• Set up a group to share leftover food
The Little Book of Green Nudges explains how to implement these and other nudges, and how to create
new nudges tailored to your own campus community.