The climate mitigation gap: Education and government recommendations miss the most effective individual actions

Abstract

Current anthropogenic climate change is the result of greenhouse gas accumulation in the atmosphere, which records the aggregation of billions of individual decisions. Here we consider a broad range of individual lifestyle choices and calculate their potential to reduce greenhouse gas emissions in developed countries, based on 148 scenarios from 39 sources. We recommend four widely applicable high-impact (i.e. low emissions) actions with the potential to contribute to systemic change and substantially reduce annual personal emissions: having one fewer child (an average for developed countries of 58.6 tonnes CO2-equivalent (tCO2e) emission reductions per year), living car-free (2.4 tCO2e saved per year), avoiding airplane travel (1.6 tCO2e saved per roundtrip transatlantic flight) and eating a plant-based diet (0.8 tCO2e saved per year). These actions have much greater potential to reduce emissions than commonly promoted strategies like comprehensive recycling (four times less effective than a plant-based diet) or changing household lightbulbs (eight times less). Though adolescents poised to establish lifelong patterns are an important target group for promoting high-impact actions, we find that ten high school science textbooks from Canada largely fail to mention these actions (they account for 4% of their recommended actions), instead focusing on incremental changes with much smaller potential emissions reductions. Government resources on climate change from the EU, USA, Canada, and Australia also focus recommendations on lower-impact actions. We conclude that there are opportunities to improve existing educational and communication structures to promote the most effective emission-reduction strategies and close this mitigation gap.

Full text

LETTER
The climate mitigation gap: education and government
recommendations miss the most effective individual actions
Seth Wynes
1,2,3
and Kimberly A Nicholas
1
1
Lund University, Centre for Sustainability Studies, PO Box 170, Lund SE-221 00, Sweden
2
University of British Columbia, The Department of Geography, Vancouver Campus, 1984 West Mall, Vancouver, BC, V6T 1Z2,
Canada
3
Author to whom any correspondence should be addressed.
E-mail: seth.wynes@gmail.com
Keywords: climate change mitigation, environmental behaviour, education, climate policy, transformation pathways
Supplementary material for this article is available online
Abstract
Current anthropogenic climate change is the result of greenhouse gas accumulation in the
atmosphere, which records the aggregation of billions of individual decisions. Here we consider a
broad range of individual lifestyle choices and calculate their potential to reduce greenhouse gas
emissions in developed countries, based on 148 scenarios from 39 sources. We recommend four
widely applicable high-impact (i.e. low emissions) actions with the potential to contribute to
systemic change and substantially reduce annual personal emissions: having one fewer child (an
average for developed countries of 58.6 tonnes CO
2
-equivalent (tCO
2
e) emission reductions per
year), living car-free (2.4 tCO
2
e saved per year), avoiding airplane travel (1.6 tCO
2
e saved per
roundtrip transatlantic flight) and eating a plant-based diet (0.8 tCO
2
e saved per year). These
actions have much greater potential to reduce emissions than commonly promoted strategies like
comprehensive recycling (four times less effective than a plant-based diet) or changing household
lightbulbs (eight times less). Though adolescents poised to establish lifelong patterns are an
important target group for promoting high-impact actions, we find that ten high school science
textbooks from Canada largely fail to mention these actions (they account for 4% of their
recommended actions), instead focusing on incremental changes with much smaller potential
emissions reductions. Government resources on climate change from the EU, USA, Canada, and
Australia also focus recommendations on lower-impact actions. We conclude that there are
opportunities to improve existing educational and communication structures to promote the
most effective emission-reduction strategies and close this mitigation gap.
1. Introduction
While 195 nations have agreed to limit the global
average temperature increase to ‘well below 2 °C’
under the December 2015 Paris Agreement (UNFCCC
2015), most current pathways to stay under the 2 °C
limit assume the future use of unproven technologies
to achieve negative emissions (Fuss et al 2014). This
has prompted calls (Anderson 2015) for near-term,
profound emissions cuts that may require changes in
lifestyle choices from the high-carbon individuals
estimated to produce nearly 50% of emissions (Gore
2015). National policies and major energy trans-
formations often take decades to change locked-in
infrastructure and institutions, but behavioural shifts
have the potential to be more rapid and widespread
(i.e. reduced reliance on cars can begin immediately,
whereas improved power plant efficiency occurs on a
decadal time frame (Pacala and Socolow 2004)).
It is especially important that adolescents are
prepared for this shift. They still have the freedom to
make large behavioural choices that will structure the
rest of their lives, and must grow up accustomed to a
lifestyle that approaches the 2.1 tonnes per person
annual emissions budget necessary by 2050 to meet
the 2 °C climate target (Girod et al 2014). Further-
more, adolescents can act as a catalyst to change their
household’s behaviour (Maddox et al 2011). While the
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Environ. Res. Lett. 12 (2017) 074024 https://doi.org/10.1088/1748-9326/aa7541
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cumulative emissions impact of any behaviour
depends both on the magnitude of the action and
its behavioural plasticity (the proportion of the public
likely to adopt a given action assuming the most
effective intervention (Dietz et al 2009)), the first step
to understanding cumulative impact is to know the
effectiveness of the action for a single person.
Here we investigate a comprehensive suite of
lifestyle choices to identify those with the greatest
potential to reduce individual greenhouse gas emis-
sions. We compare our findings with recommenda-
tions from high school science textbooks and
government resources. Previous studies have already
evaluated some of the most effective actions for
reducing energy consumption (Attari et al 2010,
Gardner and Stern, 2008) and mitigating climate
change through personal actions (Girod et al 2014),
though individuals have a poor understanding of
which actions are more effective than others (Attari
et al 2010). Our research builds on these studies by
including additional actions that have greater emis-
sions reduction potential but have not been previously
evaluated. Our methodology makes each action
comparable for individuals making the decision to
undertake them, and our analysis of official educa-
tional and government materials shows the extent to
which public institutions currently recognize the
importance of and encourage these behaviours.
2. Methods
2.1. High-impact actions
To identify our high-impact actions, we analyzed the
literature to compile a candidate list of actions for
emissions analysis. To choose data sources, we first
used peer-reviewed literature with a life-cycle ap-
proach where available (to analyze the impact of diet
and personal vehicles), followed by government
reports, grey literature or carbon calculators (green
energy, aviation). We analyzed studies from all
countries we could find, but in the main text only
report results from developed nations (the full range of
studies are available in the online supplementary
materials available at stacks.iop.org/ERL/12/074024/
mmedia). The choice to focus on developed regions
was motivated by the higher emission and consump-
tion levels in those regions, which demand steeper
emissions cuts in order to attain the same, low per
capita emissions target that will avoid dangerous
planetary warming (Girod et al 2013).
For calculations, all actions were framed in such a
way that they would take the maximum possible effect.
For instance, recycling is framed as recycling compre-
hensively for a year, a plant-based diet is framed as
avoiding all meat, and purchasing renewable energy is
framed as purchasing all possible household energy
from renewable sources for a year, even though it would
be possible to perform these actions as half-measures.
Since the unit of analysis was the individual, we
wanted country-specific data to inform the most
relevant individual choices possible. Therefore,
household and vehicular actions were divided by
the average household or vehicle occupancy of the
country where the study was performed to yield results
measured in tonnes of CO
2
-equivalent per year
(tCO
2
e per year) per individual. The types of
greenhouse gases included in these calculations varied
with the methodologies of the different studies or
sources. We also made calculations using country or
region-specific data, such as average annual kilometers
travelled per vehicle in a region (except where study
parameters explicitly stated alternative values), to
generate final values that are representative for each
study area (see supplementary materials 1).
For the action ‘have one fewer child,’we relied on a
study which quantified future emissions of descend-
ants based on historical rates, based on heredity
(Murtaugh and Schlax 2009). In this approach, half of
a child’s emissions are assigned to each parent, as well
as one quarter of that child’s offspring (the grand-
children) and so forth. This is consistent with our use
of research employing the fullest possible life cycle
approach in order to capture the magnitude of
emissions decisions.
In the case of aviation, some carbon calculators
made use of a radiative forcing index, which accounts
for the additional warming effects of gases other than
CO
2
produced during air travel. Though this results in
higher estimates than if the index had not been used,
the life cycle studies which we also included for
aviation (and which did not use radiative forcing)
provided similar final values. See supplementary
materials 2 for calculations.
In practice, the emissions benefits of undertaking
high-impact actions may be reduced by substitution
effects (where avoidance of emissions from one action is
replaced by emissions from another action) and
rebound effects (where reduced consumption in one
area leads to increased consumption elsewhere). For
instance, the emissions saved from living car-free may be
lower than we calculated if public transit replaces car
travel instead of biking or walking (living car free
represents all the emissions associated with the life
cycle of owning a car in our methodology). But even if
the number of kilometers travelled remains constant, a
switch from driving a sedan to taking public transit has
been shown to reduce emissions by 26%–76% (Chester
et al 2013). Since data that included rebound effects were
only available for some actions, we excluded rebound
effects to maintain comparability between actions.
2.2. Textbook analysis
Textbooks are a useful indicator of the content that
students are receiving in classrooms; they are based on
government-mandated curriculum documents and
serve as a resource for both students and teachers. This
may be especially true for subjects such as climate
Environ. Res. Lett. 12 (2017) 074024
2

change where a teacher is more likely to be
uncomfortable with the material (Kim and Fortner
2006, Chambers 2011). Ten textbooks used in seven of
Canada’s ten provinces were therefore analyzed (see
supplementary materials 3).
To determine which science textbooks are in use in
each province we relied on the experience of the first
author as a secondary school science teacher in
Canada, and also contacted curriculum writers and
educators from provinces where textbook usage could
not be easily determined. The provinces covered by
our analysis represent more than 80% of Canada’s
student population (we were unable to obtain the
textbooks used by the provinces of Alberta, Manitoba,
and Nova Scotia).
Only the textbook chapters directly addressing
climate change were analyzed. Statements from the
textbooks were identified as suggested actions when
they included direct recommendations (e.g. ‘eat less
meat’), or were directed at the reader using pronouns
such as ‘you’or ‘we’. Statements using ‘individuals’and
‘consumers’often explained sources of emissions
without suggesting how to reduce those emissions,
and were therefore not counted.
Due to the large number of unique recommen-
dations found in textbooks, we grouped similar
specific recommendations into various categories.
For example, suggestions such as ‘use cloth shopping
bags’and ‘purchase a reusable water bottle’would
both be listed under the category ‘reuse’. Where
possible, these categories are the same in the analysis
of textbooks and government documents. For each
textbook, we recorded the frequency of each type of
suggestion. In our coding system, a single sentence
referring to a specific topic was given the same value
as a paragraph devoted to a single topic. If a
paragraph on a broad topic (e.g. household heating)
included many specific suggestions (turn down
thermostat, purchase a more efficient heater), then
each specific suggestion was counted towards the
total.
2.3. Government documents
To analyze broad societal mitigation recommenda-
tions, we chose three developed regions with high per-
capita emissions and government documents available
in English: Australia (average per-capita emissions of
16.3 tCO
2
per year), Canada (13.5 tCO
2
per year), and
the United States (16.4 tCO
2
per year), as well as a
lower-emission case, the European Union (6.7 tCO
2
per year) (World Bank 2016). We identified the most
authoritative and relevant set of recommendations
from that region indicating how their citizens can help
mitigate climate change, contacting government
representatives for clarification where multiple possi-
ble documents were found. The frequency of
individual recommendations was recorded using the
same methods as described in the analysis of science
textbooks.
3. Results
From analyzing 148 scenarios of the climate impact of
individual behaviours in ten individual countries (with
some studies additionally considering the whole EU
region), drawn from 39 sources, we have identified a
dozen actions, including four recommended actions
that are of substantial magnitude throughout the
developed world (see supplementary materials 4):
having one fewer child, living car free, avoiding air
travel, and eating a plant-based diet (figure 1). Each of
these actions was high-impact (reduces an individual’s
greenhouse gas emissions by at least 0.8 tCO
2
e per year,
about 5% of current annual emissions in the US or
Australia) regardless of study parameters. They are also
‘best in class’—most fully achieving emissions reduc-
tions within a given domain (e.g. car travel), and with
the potential to contribute to systemic change (for
example, living car-free reduces the need to build more
roads and parking spaces, and supports higher-density
urban design, which more efficient cars do not).
We originally hypothesized that two additional
actions, not owning a dog and purchasing green
energy, would also fit our criteria for recommended
high-impact actions, but found both to be of
questionable merit. Only two studies with conflicting
results could be found for dog ownership (Eady et al
2011, Rushforth and Moreau 2013), so we have not
included it in figure 1(see supplementary materials 2).
For green energy, researchers have described problems
with double-counting in several European countries
(Hast et al 2015), as seen in the near-zero emission
reductions for Great Britain in figure 1. Still, in regions
with carbon-based energy grids such as Australia and
North America, green energy has the potential to
greatly reduce emissions associated with home energy
use, which is why we retained this action in figure 1.
Previous studies that compare the effectiveness of
various actions tend to focus on moderate-impact
actions (saving between 0.2 and 0.8 tCO
2
eyear)or
even low-impact actions (saving <0.2 tCO
2
e).
Compare for instance two actions cited as among
the most effective ways to reduce household energy
usage (hang drying clothing (0.21 tCO
2
e) and
washing clothing in cold water (0.25 tCO
2
e) (Attari
et al 2010)) with any of the high-impact actions
shown in green (figure 1). Our recommended high-
impact actions are more effective than many more
commonly discussed options (e.g. eating a plant-
based diet saves eight times more emissions than
upgrading light bulbs). More significantly, a US
family who chooses to have one fewer child would
provide the same level of emissions reductions as 684
teenagers who choose to adopt comprehensive
recycling for the rest of their lives.
To illustrate the implications of our findings,
consider that per capita emissions must reach 2.1
tCO
2
e by 2050, if warming of the planet is to be kept
below 2 °C (Girod et al 2013). Using values from
Environ. Res. Lett. 12 (2017) 074024
3

figure 1, we estimate that an individual who eats
meat and takes one roundtrip, transatlantic flight
per year emits 2.4 tCO
2
e through these actions,
exhausting their personal carbon budget, without
accounting for any other emissions. It would help meet
climate goals if such an individual chose to shift her or
his behaviour, as technological advances may be
unable to sufficiently reduce emissions from these two
actions even by 2050 (Girod et al 2013). These two
sectors are an agreed area of focus for reduced
demand, as aviation is likely to be the last of all
transport modes to mainstream low-carbon standards
(Kivits et al 2010) and studies show we cannot expect
to stay under a 2 °C limit without at least some shifts in
diet (Hedenus et al 2014).
These results also highlight the greater reductions
available from moving away from a polluting technol-
ogy (living car-free, 2.4 tCO
2
e per year lower than the
baseline of a gasoline automobile) compared with using
the cleanest available technology (electric cars, which
still emit 1.15 tCO
2
e per year on average) or incremental
technological improvements (increase vehicle fuel
economy by buying a more efficient gasoline car,
1.19 tCO
2
e saved per year). Though electric cars may
replace internal combustion vehicles and shrink the
carbon footprint of the automobile, the car-based
transport model itself still allows for low-density rural
housing developments (Muller 2004), which are
associated with twice the emissions per capita of
high-density housing (Norman et al 2006) as well
as greater consumption and energy use (Ala-Mantila
et al 2014, Shammin et al 2010). A car-free lifestyle
reduces traffic congestion and petroleum dependence
(Mashayekh et al 2012) and avoids the environmental
toxicity issues surrounding electric vehicle production
(Hawkins et al 2013), making it advantageous even in
an era of low-emission vehicles. Lastly, until the
emissions associated with desired services are reduced
to zero, population will continue to be a multiplier of
emissions (Waggoner and Ausubel 2002).
Having identified which actions are high or low-
impact, it is worthwhile to know whether governments
and educators are emphasizing high-impact actions.
Since we consider adolescents an ideal demographic to
adopt high-impact actions, we analyzed ten Canadian
high school science textbooks (see supplementary
materials 3) to find which broad categories as well as
specific actions are currently recommended to
adolescents for reducing emissions.
We found that the 216 individual recommended
actions from textbooks overwhelmingly focused on
moderate or low-impact actions, with our recom-
mended actions mostly presented in a less effective
form, or not at all (only eight mentions, or 4%). No
textbook suggested having fewer children as a way to
reduce emissions, and only two out of ten mentioned
avoiding air travel (figure 2). Eating a plant-based diet
was presented in the form of moderate-impact actions
such as eating less meat, even though a completely
plant-based diet can be 2 to 4.7 times more effective at
reducing greenhouse gas emissions than decreased
meat intake (Meier and Christen 2012). Similarly,
methods for reducing one’s impact while driving were
mentioned almost 30 times, with only six mentions of
a car-free lifestyle. Instead, the recommendation
category mentioned in the most textbooks was
0
1
Emissions savings (tCO2e per year)
2
3
4
20
40
60
80
100
120
Have one
fewer child
USA
USA
USA
USA
AUS
CAN
AUS
GBR NZL
USA,GBR
AUS
JPN
RUS
CAN
BEL
EU
GBR
GBR
BEL
EU
DEU
NLD
USA
High-Impact (>0.8 tCO2e) Low-Impact (<0.2 tCO2e) Mean regional valueModerate-Impact (0.2-0.8 tCO2e)
Live car
free
Avoid one
transatlantic
flight
Buy green
energy
Buy more
efficient
car
Replace
gasoline
with hybrid
Switch
electric car
to car free
Plant-based
diet
Wash
clothes in
cold water
Recycle Hang dry
clothes
Upgrade
light bulbs
Figure 1. A comparison of the emissions reductions from various individual actions. The height of the bar represents the mean of all
studies identified in developed nations, while black lines indicate mean values for selected countries or regions (identified by ISO
codes) where data were available from specific studies. We have classified actions as high (green), moderate (blue), and low (yellow)
impact in terms of greenhouse gas emissions reductions. Note the break in the y-axis. See supplementary materials 5 for details.
Environ. Res. Lett. 12 (2017) 074024
4

recycling (seven of ten textbooks) and the recommen-
dation category with the most individual actions
mentioned was energy conservation (32 mentions)
(figure 2).
This trend of focusing on lower-impact actions is
generalizable in other developed countries. We
analyzed four government guides, each selected as
an authoritative source for its region and found a focus
on moderate-impact actions such as recycling or
reducing home energy use (table 1). Except for a
handful of references to the quantity of emissions
saved by specific actions (altogether missing from the
Canadian guide), these guides provided little infor-
mation for users to discern which actions might be
more effective, and therefore which to prioritize.
Regarding our identified high-impact actions, no
guide recommended having fewer children or eating a
plant-based diet, though the EU guide did suggest
eating less meat and more vegetables. Neither the US
nor Australian guides suggested avoiding air travel. All
government guides discussed reducing the impact of
personal vehicles through buying cleaner cars or
driving or maintaining them better, and all suggested
increased use of cycling or public transport, but only
Australia adopted the framing of a car-free lifestyle.
4. Discussion
While past research has focused on incremental
behavioural changes that require minimal effort on the
part of individuals (Dietz et al 2009), we propose to
empower individuals to focus on changing the
behaviours that are most effective at reducing their
personal emissions. Many of these changes can be seen
as desirable choices that promote a slower and
healthier lifestyle (Soret et al 2014, Frank et al
2004). In addition to adolescents, it would also be
beneficial for those who are already willing to make
impactful lifestyle changes for the sake of the climate
to be aware of which actions will be most effective.
Serious behavioural change is possible; there is
evidence that younger generations are willing to depart
from current lifestyles in environmentally relevant
ways. For instance, the United States has seen as a
measurable decrease (Kuhnimhof et al 2013) or at the
very least, delay in car usage and ownership for the
millennial generation compared to previous gener-
ations (Garikapati et al 2016). In terms of plant-based
diets, the willingness of individuals to eat less meat
increases with the perceived effectiveness of this
action, which suggests the need for increased
0
5
5
1
4
4
6
4
7
5
5
5
4
2
2
4
6
1
6
6
0
0
0
4
1
1
1
3
3
2
Low-ImpactHigh-Impact
Join organization
Spread awareness
Petition
Vote
Buy organic food
Reduce lawn mowing
Purchase carbon offsets
Compost
Eat local
Recycle
Reuse
Reduce consumption
Eat less meat
Conserve energy
Use public transportation, bike, walk
Install solar panels/renewables
Home heating/cooling efficiency
Buy green energy
Reduce effects of driving
Eat a plant-based diet
Have one fewer child
Live car free
Avoid air travel
Buy energy efficient products
Plant a tree
Conserve water
Minimize waste, buy less packaging
Eliminate unnecessary travel
Letter to company/elected official
Moderate-Impact Civic
Number of mentions in ten high school textbooks
10 20 30 40
Figure 2. An analysis of individual actions recommended for mitigating climate change in ten Canadian high school science
textbooks. The number of unique textbooks making each recommendation is shown at the end of each bar. Recommendations are
approximately ranked from most effective at reducing greenhouse gas emissions at the top to least effective at the bottom, following
data in figure 1(we have not quantified the emissions reductions from civic actions). Recommended actions (based on emissions
savings in figure 1) are in bold. See supplementary materials 3 for full breakdown and list of textbooks.
Environ. Res. Lett. 12 (2017) 074024
5

awareness of the most effective options for sustainable
dietary changes (De Boer et al 2016).
However, even knowledgeable and willing indi-
viduals may not reduce meat intake or adopt other
high impact actions if cultural norms or structural
barriers act as obstacles. For example, western cultural
norms associate meat with wealth, status and luxury
(Ruby 2012) and meat consumption per capita in the
richest 15 nations is 750% higher than in the poorest
24 nations (Tilman and Clark 2014). Just as cultural
norms promote meat consumption, structural choices
such as sprawling neighbourhoods can promote
individuals’use of high carbon transport (Cervero
2002). Shifts in public policy, such as a carbon tax on
food commodities (Springmann et al 2016)or
encouraging compact urban growth (Hankey and
Marshall 2010), can address these barriers. The
benefits of such policies extend beyond climate
change; plant-based diets conserve biodiversity and
reduce illnesses like cancer and type II diabetes
(Tilman and Clark 2014) while car-free living can
reduce obesity (She et al 2017) and airborne pollutants
(Chester et al 2013).
Though we have analyzed the transmission of
information, we do not intend to endorse the widely
criticized knowledge deficit model of behaviour
(Kahan et al 2012), which holds that people will act
to prevent climate change if they understand it better.
Table 1. Actions recommended in government documents to reduce an individual’s greenhouse gas emissions. CO
2
reductions are
based on sources from figure 1(see supplementary materials 4), unless otherwise noted. Our recommended high impact actions are
shown in bold. Results are from four government sources: ‘Take Action’from Australia (Department of Industry and Science 2014),
‘Top 10 Things You Can Do To Help’from Canada (Government of Canada 2012), ‘Climate Action’from the European Union
(European Commission, 2015) and ‘What You Can Do’from the United States (EPA 2015).
Behaviour Example Approximate CO
2
e reduced per year (kg) AUS CAN USA EU
High Impact Actions
Have one fewer child 23 700–117 700
Live car free 1000–5300 x
Avo i d o ne flight (depending on
length)
700–2800 x x
Purchase green energy <100–2500 x x x x
Reduce effects of driving Buy more efficient car 1190 x x x x
Eat a plant-based diet 300–1600
Moderate Impact Actions
Home heating/cooling efficiency Wall insulation 180 (Chitnis et al 2013)xxxx
Install solar panels/renewables Rooftop solar x x x
Use public transportation, bike,
walk
xxxx
Buy energy efficient products Energy Star x x x x
Conserve energy Hang dry clothes 210 x x x x
Reduce food waste No food waste 370 (Hoolohan et al 2013)xx
Eat less meat 230 (Meier and Christen 2012)x
Reduce consumption Pay bills online x x x
Reuse Reusable shopping bag 5 (Dickinson et al 2009)xxxx
Recycle 210 x x x x
Eat local 0–360 (Coley et al 2009, Weber and Matthews
2008)
x
Low Impact Actions
Conserve water Run full dishwasher x x x x
Eliminate unnecessary travel xx
Minimize waste xx
Plant a tree 6–60 (Freedman and Keith 1996)xx
Compost xxx
Purchase carbon offsets x
Reduce lawn mowing Let lawn grow longer x
Ecotourism Use Ecolabelled
accommodation
x
Keep backyard chickens x
Buy Ecolabel products x
Calculate your home’s footprint x
Civic Actions
Spread awareness x
Influence employer’s actions xx
Influence school’s actions x
Environ. Res. Lett. 12 (2017) 074024
6

Tested strategies for promoting individual actions to
mitigate climate change have been explored elsewhere,
such as showing students how to use public transit,
rather than simply encouraging it (Cornelius et al
2014). But before these strategies can be widely
implemented in classrooms, there must be accurate
information to prioritize actions in curriculum
documents and teaching materials such as textbooks.
Some high-impact actions may be politically
unpopular, but this does not justify a focus on
moderate or low-impact actions at the expense of
high-impact actions. As a specific example, one
textbook says ‘making a difference doesn’t have to
be difficult’and provides the example of switching
from plastic bags to reusable shopping bags in order to
save 5kg of CO
2
per year (Dickinson et al 2009). This is
less than 1% as effective as a year without eating meat.
Examples like this create the impression that the issue
of climate change itself is trivial in nature, and
represent missed opportunities to encourage serious
engagement on high-impact actions.
It is possible that textbook and government writers
intentionally selected low-impact actions because they
are frequent and easy to perform. If so, this would
likely follow the ‘foot-in-the-door technique’, a type of
positive spillover where encouraging small actions is
hoped to lead individuals to take more substantial
behaviours later (Thøgersen and Crompton 2009).
Unfortunately, empirical evidence of the spillover
effect is mixed. Some interventions result in an
increase in other pro-environmental behaviours but
most examples of positive spillover occur between
similar actions, i.e. not from small actions to
substantial ones (Truelove et al 2014). Early results
also indicate that high-commitment, pro-social
behaviours are more likely to cause further positive
spillover (Gneezy et al 2012), which supports an
emphasis on high-impact actions as a way to change
overall norms.
Regardless of spillover effects, some actions will
doubtless have a reduced cumulative emissions impact
because barriers currently limit their uptake on a large
scale. But the inclusion of such actions in textbooks
demonstrates the seriousness of climate change, and
offers a starting point for important discussions that
challenge unsustainable societal norms.
Whether the goal is to slowly change societal
norms or to encourage significant personal emissions
reductions, adolescence is an ideal time for interven-
tion. The majority of the textbooks that we analyzed
are aimed at Grade 10 students (typically age 16),
which is the same age that most Canadians are first
allowed to obtain a driver’s license (Government of
Canada 2014). Adolescents can also choose their own
diets, can influence family decisions on vacations (e.g.
flying vs. staying local) and should be informed of the
environmental consequences of family size as they are
likely becoming sexually active. Though a 50-year-old
car owner with an established lifestyle living in the
suburbs might be better able to adopt a recommen-
dation to drive a more efficient car, there are
qualitative (paradigm shifting of social norms) and
quantitative (emissions reduction) reasons for an
adolescent to instead receive the high-impact message:
‘live car free’.
It is important to acknowledge the limitations and
uncertainty of the data that we have presented. We
provide mean values for our recommended actions,
but we do not suggest that these are firm figures
universally representative of each action, but instead
best estimates. For instance, a transatlantic flight will
differ in emissions magnitude based on the exact
distance travelled, weight of a passenger’s luggage, the
occupancy of the plane, wind speed and many other
variables, in addition to the differences inherent in
varying assessment methodologies. Our estimations
are most useful when they compare different classes of
actions that vary substantially. Similarly, we have
presented lists of actions (figure 2and table 1) which
are ranked approximately from highest to lowest-
impact in reducing greenhouse gas emissions. Actions
are placed into groups which are qualitatively similar,
but may be highly variable by emissions impact. Still
the differences between a high-impact and a low-
impact action are considerable.
5. Conclusion
We have identified four recommended actions which
we believe to be especially effective in reducing an
individual’s greenhouse gas emissions: having one
fewer child, living car-free, avoiding airplane travel,
and eating a plant-based diet. These suggestions
contrast with other top recommendations found in the
literature such as hang-drying clothing or driving a
more fuel-efficient vehicle. Our results show that
education and government documents do not focus
on high-impact actions for reducing emissions,
creating a mitigation gap between official recom-
mendations and individuals willing to align their
behaviour with climate targets. Focusing on high-
impact actions (through providing accurate guidance
and information, especially to ‘catalytic’individuals
such as adolescents) could be an important dimension
of scaling bottom-up action to the transformative
decarbonisation implied by the 2 °C climate target,
and starting to close this gap.
Acknowledgments
We would like to thank Steve Davis, Kevin Anderson,
and Amanda Carrico for their helpful suggestions on
earlier drafts of this paper. Three anonymous reviewers
provided thoughtful reviews.
Environ. Res. Lett. 12 (2017) 074024
7

References
Ala-Mantila S, Heinonen J and Junnila S 2014 Relationship
between urbanization, direct and indirect greenhouse gas
emissions, and expenditures: a multivariate analysis Ecol.
Econ. 104 129–39
Anderson K 2015 Duality in climate science Nat. Geosci. 8
898–900
Attari S Z, DeKay M L, Davidson C I and Bruine de Bruin W
2010 Public perceptions of energy consumption and
savings Proc. Natl Acad. Sci. 107 16054–9
Cervero R 2002 Built environments and mode choice: toward a
normative framework Transport. Res. D7265–84
Chambers J M 2011 Right time, wrong place? Teaching about
climate change in Alberta schools Alberta Sci. Educ. J. 42
4–12
Chester M, Pincetl S, Elizabeth Z, Eisenstein W and Matute J
2013 Infrastructure and automobile shifts: positioning
transit to reduce life-cycle environmental impacts for
urban sustainability goals Environ. Res. Lett. 8015041
Chitnis M, Sorrell S, Druckman A, Firth S K and Jackson T
2013 Turning lights into flights: estimating direct and
indirect rebound effects for UK households Energy Policy
55 234–50
Coley D, Howard M and Winter M 2009 Local food, food miles
and carbon emissions: a comparison of farm shop and
mass distribution approaches Food Policy 34 150–5
Cornelius M, Armel K C, Hoffman K, Allen L, Bryson S W,
Desai M and Robinson T N 2014 Increasing energy-and
greenhouse gas-saving behaviors among adolescents: a
school-based cluster-randomized controlled trial Energy
Efficiency 7217–42
De Boer J, de Witt A and Aiking H 2016 Help the climate,
change your diet: a cross-sectional study on how to involve
consumers in a transition to a low-carbon society Appetite
98 19–27
Department of Industry and Science 2014 Take action Your
Energy Savings (www.yourenergysavings.gov.au/)
Dickinson T, Edwards L, Flood N, Grace E, Jackson C, Mazza M
and Ross J 2009 ON Science 10 (Whitby, ON: McGraw-
Hill Ryerson Ltd)
Dietz T, Gardner G T, Gilligan J, Stern P C and Vandenbergh M
P 2009 Household actions can provide a behavioral wedge
to rapidly reduce US carbon emissions Proc. Natl Acad.
Sci. 106 18452–6
Eady S, Sanguansri P, Bektash R, Ridoutt B, Simons L and
Swiergon P 2011 Carbon foot-print for Australian
agricultural products and downstream food products in
the supermarket 7th Australian Conf. on Life Cycle
Assessment (Melbourne, Australia, 9–10 March 2011)
EPA 2015 What you can do Climate Change: United States
Environmental Protection Agency (www.epa.gov/
climatechange/wycd/)
European Commission 2015 What you can do Climate Action
(http://ec.europa.eu/clima/citizens/tips/index_en.htm)
Frank L D, Andresen M A and Schmid T L 2004 Obesity
relationships with community design, physical activity, and
time spent in cars Am. J. Prev. Med. 27 87–96
Freedman B and Keith T 1996 Planting trees for carbon credits:
a discussion of context, issues, feasibility, and
environmental benefits Environ. Rev. 4100–11
Fuss S, Canadell J G, Peters G P, Tavoni M, Andrew R M, Ciais
P, Jackson R B, Jones C D, Kraxner F and Nakicenovic N
2014 Betting on negative emissions Nat. Clim. Change 4
850–3
Gardner G T and Stern P C 2008 The short list: The most
effective actions US households can take to curb climate
change Environ.: Sci. Pol. Sust. Dev. 50 12–25
Garikapati V M, Pendyala R M, Morris E A, Mokhtarian P L
and McDonald N 2016 Activity patterns, time use, and
travel of millennials: a generation in transition? Transport
Rev. 36 558–84
Girod B, Van Vuuren D P and Hertwich E G 2013 Global
climate targets and future consumption level: an
evaluation of the required GHG intensity Environ. Res.
Lett. 8014016
Girod B, van Vuuren D P and Hertwich E G 2014 Climate policy
through changing consumption choices: options and
obstacles for reducing greenhouse gas emissions Glob.
Environ. Change 25 5–15
Gneezy A, Imas A, Brown A, Nelson L D and Norton M I 2012
Paying to be nice: Consistency and costly prosocial
behavior Manag. Sci. 58 179–87
Gore T 2015 Extreme Carbon Inequality: Why the Paris climate
deal must put the poorest, lowest emitting and most
vulnerable people first Report (Oxford: Oxfam
International) (http://policy-practice.oxfam.org.uk/
publications/extreme-carbon-inequality-why-the-paris-
climate-deal-must-put-the-poorest-lowes-582545)
Government of Canada 2012 Top 10 Things You Can Do
Canada’s Action on Climate Change (www.climatechange.
gc.ca/default.asp?lang=en&n=D27052CE-1)
Government of Canada 2014 Getting your driver’s license (www.
youth.gc.ca/eng/life_events/drivers_license.shtml)
Hankey S and Marshall J D 2010 Impacts of urban form on
future US passenger-vehicle greenhouse gas emissions
Energy Policy 38 4880–7
Hast A, Syri S, Jokiniemi J, Huuskonen M and Cross S 2015
Review of green electricity products in the United
Kingdom, Germany and Finland Renew. Sust. Energy Rev.
42 1370–84
Hawkins T R, Singh B, Majeau-Bettez G and Strømman A H
2013 Comparative environmental life cycle assessment of
conventional and electric vehicles J. Ind. Ecol. 17
53–64
Hedenus F, Wirsenius S and Johansson D A 2014 The
importance of reduced meat and dairy consumption for
meeting stringent climate change targets Clim. Change 124
79–91
Hoolohan C, Berners-Lee M, McKinstry-West J and Hewitt C
2013 Mitigating the greenhouse gas emissions embodied in
food through realistic consumer choices Energy Policy 63
1065–74
Kahan D M, Peters E, Wittlin M, Slovic P, Ouellette L L, Braman
D and Mandel G 2012 The polarizing impact of science
literacy and numeracy on perceived climate change risks
Nat. Clim. Change 2732–5
Kim C and Fortner R W 2006 Issue-specific barriers to
addressing environmental issues in the classroom: an
exploratory study J. Environ. Educ. 37 15–22
Kivits R, Charles M B and Ryan N 2010 A post-carbon aviation
future: airports and the transition to a cleaner aviation
sector Futures 42 199–211
Kuhnimhof T, Zumkeller D and Chlond B 2013 Who made peak
car, and how? A breakdown of trends over four decades in
four countries Transport Rev. 33 325–42
Maddox P, Doran C, Williams I D and Kus M 2011 The role of
intergenerational influence in waste education
programmes: the THAW project Waste Manage. 31
2590–600
Mashayekh Y, Jaramillo P, Samaras C, Hendrickson C T,
Blackhurst M, MacLean H L and Matthews H S 2012
Potentials for sustainable transportation in cities to
alleviate climate change impacts Environ. Sci. Technol. 46
2529–37
Meier T and Christen O 2012 Environmental impacts of dietary
recommendations and dietary styles: Germany as an
example Environ. Sci. Technol. 47 877–88
Muller P O 2004 The Geography of Urban Transportation ed S
Hanson and G Giuliano (New York: Guildford
Publications)
Murtaugh P A and Schlax M G 2009 Reproduction and the
carbon legacies of individuals Glob. Environ. Change 19
14–20
Environ. Res. Lett. 12 (2017) 074024
8

Norman J, MacLean H L and Kennedy C A 2006 Comparing
high and low residential density: life-cycle analysis of
energy use and greenhouse gas emissions J. Urban Plan.
Dev. 132 10–21
Pacala S and Socolow R 2004 Stabilization wedges: solving the
climate problem for the next 50 years with cur rent
technologies Science 305 968–72
Ruby M B 2012 Vegetarianism. A blossoming field of study
Appetite 58 141–150
Rushforth R and Moreau M 2013 Finding your dog’s ecological
‘pawprint’: a hybrid EIO-LCA of dog food manufacturing
Course Project Report Series SSEBE-CESEM-2013-CPR-005
(Tempe, AZ: Center for Earth Systems Engineering and
Management, Arizona State University)
Shammin M R, Herendeen R A, Hanson M J and Wilson E J
2010 A multivariate analysis of the energy intensity of
sprawl versus compact living in the US for 2003 Ecol.
Econ. 69 2363–73
She Z, King D M and Jacobson S H 2017 Analyzing the impact
of public transit usage on obesity Prev. Med. 99 264–8
Soret S, Mejia A, Batech M, Jaceldo-Siegl K, Harwatt H and
Sabaté J 2014 Climate change mitigation and health effects
of varied dietary patterns in real-life settings throughout
North America Am J. Clin. Nutr. 100 490S–5S
Springmann M, Mason-D’Croz D, Robinson S, Wiebe K,
Godfray H C J, Rayner M and Scarborough P 2016
Mitigation potential and global health impacts from
emissions pricing of food commodities Nat. Clim. Change
769–74
Thøgersen J and Crompton T 2009 Simple and painless? The
limitations of spillover in environmental campaigning J.
Consum. Policy 32 141–63
Tilman D and Clark M 2014 Global diets link environmental
sustainability and human health Nature 515 518–22
Truelove H B, Carrico A R, Weber E U, Raimi K T and
Vandenbergh M P 2014 Positive and negative spillover of
pro-environmental behavior: an integrative review and
theoretical framework Glob. Environ. Change 29 127–38
UNFCCC 2015 Adoption of the Paris Agreement
Waggoner P E and Ausubel J H 2002 A framework for
sustainability science: a renovated IPAT identity Proc. Natl
Acad. Sci. 99 7860–5
Weber C L and Matthews H S 2008 Food-miles and the relative
climate impacts of food choices in the United States
Environ. Sci. Technol. 42 3508–13
World Bank 2016 CO
2
emissions (metric tons per capita) (http://
data.worldbank.org/indicator/EN.ATM.CO2E.PC?view=
map)
Environ. Res. Lett. 12 (2017) 074024
9