Expert Perspectives

Changing Behavior to Help Meet Long-Term Climate Targets

The necessity of behavior change to meet climate targets

Current projections for decarbonization of energy, combined with business-as-usual projections of growth in demand for goods and services, are incompatible with the rapid reduction in emissions necessary to meet Paris and national climate targets. Seventy-two percent of global greenhouse gas emissions come from household or “lifestyle” consumption, including mobility, diet, and housing, as opposed to government or capital and infrastructure investment (Hertwich and Peters 2009). These lifestyle emissions must aim for 2.5 tCO2e per capita by 2030 and 0.7 tCO2e by 2050 to be in line with the Paris goal of limiting global temperature increase to 1.5°C above preindustrial levels without extensive reliance on negative emissions; current lifestyle emissions are 10.4 tCO2e for Finland, 4.2 for China, and 2.0 for India (Institute for Global Environmental Strategies et al. 2019). The goal of reaching net zero emissions is unlikely to be achieved through a timely technological change alone and, in addition to policy and investment changes, will likely rely in part on reduced consumption of high-emissions goods and services (Masson-Delmotte et al. 2018).

Aviation, for example, is a difficult sector to decarbonize, and while biofuels offer one solution, they would compete for land use with other priorities like food production and biodiversity conservation (Bows-Larkin and Anderson 2013). Electrification is more promising in land transport, since electric aircraft are projected to be limited in range (Schäfer et al. 2018) and mature too slowly to achieve necessary short-term emissions reductions (Bows-Larkin 2015), indicating the need for demand reduction. Similar barriers exist in agriculture, where methane-producing livestock cannot be decarbonized like an energy grid, and expected improvements in crop yields cannot meet growing demand for animal-intensive diets. Shifts to more plant-based diets, however, remain a viable solution (Bajželj et al. 2014), particularly in high- or medium-income nations. In sum, large-scale behavior change away from today’s high-emitting lifestyles is a prerequisite for meeting our Paris climate commitments.

Why is behavior change relevant for long-term climate strategies?

Behavioral change is largely neglected in analyses of climate change mitigation for meeting international targets (Creutzig et al. 2016), despite the necessity of driving behavioral change in areas like aviation and meat consumption (Girod et al. 2013; Hedenus et al. 2014). National long-term climate strategies present an important opportunity for exploring novel approaches, potentially using multiple scenarios or backcasting techniques, to help stimulate a creative vision for what a future compatible with the Paris goals can look like. Ongoing research in many countries could inform long-term, deep emissions reductions strategies that include behavior change, but, at present, most long-term strategies do not take advantage of this opportunity. For example, researchers in Sweden have formulated four normative backcasting scenarios compatible with 1.5°C, using radically different approaches to achieve this: local self-sufficiency, circular economy in the welfare state, collaborative economy, and automation for quality of life (Francart et  al. 2018). A vision for a sustainable Nordic food system has recently been formulated in participatory, normative scenario development between researchers and agricultural stakeholders for a desirable food system. This process generated an organic, diversified local diet where animals were only fed on grazing or waste products, thus limiting competition with food for humans. The resulting diet was about 80 percent lower in both overall meat consumption and greenhouse gas emissions than today’s diet (Karlsson et al. 2018).

Long-term climate strategies offer a unique space to consider emissions that go beyond the scope of territorial borders, such as those from air travel. Aviation emissions are currently largely under voluntary airline industry self-governance, but there is increasing need for countries to take these emissions into account, and to reform policies such as the current subsidy airlines receive in the form of not paying taxes on international fuels (Gössling et al. 2017). Many current national climate plans extrapolate continued growth in aviation demand, without acknowledging the increasingly large share of the remaining carbon budget this would consume (Cames et al. 2015), thus putting greater reduction burdens on all other sectors. For realistic carbon budgets that will meet national and international goals, aviation should be included in national climate plans and should explore demand reduction in this emissions-intensive sector. Nations could begin planning for more low-carbon, regional tourism and countries currently dependent on tourism from long-distance air travel might consider scaling down these operations over time while seeking alternative livelihoods for tourism-dependent economies.

The EU long-term strategy acknowledges the need for more rail infrastructure but address aviation emissions mostly through a focus on technical solutions such as fuel switching, without exploring the need for reduced long-haul travel to meet climate goals. The current culture of cheap, prolific air travel, and the extrapolation of current aviation demand into the future, cannot coexist with meeting international climate targets. At the moment, individuals are frequently incentivized both culturally and financially to travel by air rather than staying local or using low-carbon alternatives. Tourism and business travel are associated with social prestige, and many people join frequent flyer programs that reward customer loyalty with the opportunity to generate more cheap emissions. Tourism currently constitutes 8 percent of global greenhouse gas emissions (greater than emissions from India; Le Quéré et al. 2018), and is projected to continue to grow (Lenzen et al. 2018). It is therefore necessary to rapidly find ways to change this culture, including new narratives that do not view continued high-emissions and fast long-distance travel as an inevitable good. Long-term strategies, which have no strict limits in scope, may offer a unique space for nations to consider ways that national policies can positively impact international emissions in sectors like aviation and tourism.

What do we know about what works to change behavior?

Behavioral changes may be neglected by some policymakers and researchers, since they are typically perceived as more value-laden than technological improvements and because they are more difficult to quantify and implement in models (Creutzig et al. 2016; Hardt et al. 2019). Fortunately, advances are being made in understanding what drives behavioral change. The high-impact areas for reducing existing greenhouse gas emissions through behavior change are reducing car travel, flying, and meat consumption (Wynes and Nicholas 2017), activities that predominate for high-income individuals and countries at present, although these actions are less commonly recommended by government resources or high school science textbooks than moderate-impact climate actions such as reducing energy consumption (Wynes et al. 2018). A great deal of research shows what works to reduce home energy use (Šćepanović et al. 2017; Abrahamse et al. 2015), including providing feedback with normative comparisons to neighbors. For personal vehicle use, a small body of research shows that interventions like providing free transit passes or e-bike rentals can encourage mode shifts by interrupting entrenched habits (Wynes et al. 2018); policymakers can also support low-carbon infrastructure such as bike lanes and public transit, or use economic incentives such as congestion pricing. However, very little research has been conducted on how to encourage reductions in meat consumption (Byerly et al. 2018), and virtually no experiments have been conducted on reducing demand for air travel (Wynes et al. 2018). We have therefore compiled a preliminary list of examples of how behavioral interventions common in other domains could be applied to air travel (see Table 1). These behavioral interventions are examples of policy experiments that could be conducted at institutional or regional levels, and which national governments could support both structurally and through funding. They could also be considered when designing long-term scenarios or backcasting from 2050 targets.

What roles can government officials play in driving behavior change?

National governments have a wide palette of policy options to choose from to support behavior change toward lower-carbon lifestyles. The traditional policy tool of making high-emitting behaviors more expensive through taxation is one option. Beyond driving behavior change, such taxes can send an important cultural signal about the social acceptability of high-emitting behaviors, which may be important in reaching the critical mass of 25 percent of a population exhibiting a behavior before it becomes the social convention (Centola et al. 2018). Public health strategies used to reduce tobacco consumption offer important examples of how governments can alter social conventions in the public interest. Here, health officials have had great success through taxation and clean air laws, but best practice in this field also relies on mass-reach communication, the cessation of protobacco advertising, and well-monitored, evidence-based interventions (Levy et al. 2007; CDC 2014; Emory et al. 2015).

Another role for national governments in driving behavior change can be to incentivize regional and local governments to take appropriate action and to be centers of innovation, as well as set up databases for tracking emissions and policies to reduce them, or coordinate information sharing on best practices. Klimatklivet is a Swedish policy where the national government funds regional, local, and business programs that reduce emissions. To date, over 3,200 projects have been supported, saving 1.57 million tons of CO2e annually, at an average cost of €38/ton (Naturvårdsverket 2018). Governments can also implement advertising bans or restrictions for high-emitting behaviors (e.g., air travel) and run educational campaigns to raise awareness of the polluting costs of high-emitting behaviors and highlight low-emitting alternatives. Increased awareness may be important to generate public support for behavior change; for example, public polling shows that individuals who are more aware of the negative effects of air travel are more likely to support public policies to curtail it (Murray 2019), and willingness to eat less meat is related to perceived efficacy of this action for climate mitigation (De Boer 2016).

How should developers of long-term strategies address behavior change?

Overall, long-term climate strategies should explicitly consider the possibility of behavior change in high-impact sectors (particularly in neglected areas such as aviation and diet, in addition to the more frequently studied car transport and energy use) when developing current and future policies. Modeling and scenario development should explore different possible degrees of behavior change, informed by the remaining carbon budget, to meet climate targets as well as normative social goals for how to achieve this fairly. These would help identify priority areas for more active monitoring and testing of policy and innovation designed to incentivize behavior change and reduce emissions in line with the Paris commitments.

Table 1. Eleven types of behavioral interventions studied in peer-reviewed literature to reduce personal greenhouse gas emissions, with suggested applications to reduce emissions from aviation

Type of intervention

Example

To reduce emissions from aviation

Nudges

 

Customers “nudged” by being given preportioned meal sizes (Friis et al. 2017).

Change defaults in government booking systems to better support booking train travel.

Prompts

Participant received text-message reminders to reduce red meat intake (Carfora et al. 2017).

 

Display a note on a travel booking website asking customer to consider linked low-carbon options.

Justification

Carbon footprint information of meal choices displayed (Brunner et al. 2018).

 

Make carbon footprint of flights versus other choices more explicit in transport mapping and travel booking systems to inform travel decision.

Instructions

Energy saving tips provided to households (Allcott 2011).

Design government and institutional travel policies that prioritize travel-free meetings, then ground-based travel (von Arnold 2018; Tyndall Centre 2019).

 

Provide instructions and technical support for institutional videoconferencing hardware and software to lower barriers for digital alternatives to air travel (Wynes and Donner 2018).

Feedback

Monthly energy statement mailed to households (Carroll et al. 2014).

Give institution members individual reports about personal air travel, including a comparison to the average member of the department or with a sustainable global citizen’s annual carbon budget (with normative, encouraging messages for those whose emissions are below the average).

 

Make public the emissions of public sector employees who generate above a certain threshold in air travel emissions. Similar social pressure interventions have been effective in encouraging behaviors like voting (Davenport et al. 2010) and reduced household energy consumption (Delmas and Lessem 2014).

Social modeling

Neighborhood leaders model a proenvironmental behavior.  

 

Highlight and promote local destinations, emphasizing the economic benefits for local economies (e.g., collaboration of Swedish universities, regional governments and tourist agencies that includes 100 vacations reachable by train, and carbon calculator for travel plans) (Klimatsmart Semester 2019).

 

Promote positive stories of slow travel and its health, quality time, adventure, and other benefits.

 

Attitudes and behavior have been changed by knowing someone who flies less or doesn’t fly (Westlake 2017).
 

Increase institutional or leadership commitment to reduced flying.

Cognitive dissonance

Stressed the gap between an individual’s actions (driving) and values (environmental concern) (Tertoolen et al. 1998).

 

Require that air travel advertisements contain messages stating the environmental harms of flying, similar to the practice with cigarette packages and pharmaceutical drug commercials.

 

Social media campaigns can highlight high emissions from air travel by “clueless influencers” (aningslosainfluencers 2019).

Commitment

Subjects committed to reduce car use (Tertoolen et al. 1998).

 

Sign personally formulated pledges at the individual, business, city, and regional levels.

Rewards

Employees offered option to cash out parking spots (Shoup 1997).

 

Employers give more days off to support employees who travel slower (e.g., Climate Perks initiative by the NGO 10:10).

Replace frequent flyer programs with a financial incentive program that rewards lower-carbon options.

Competition

Group competition reduced energy use at university residence (Sintov 2016).

 

Stimulate interdepartmental competition to reduce air travel emissions at large public institutions.

Goal

Group goal of 5% energy reduction given to households (Abrahamse et al. 2007).

 

Align aviation with Paris temperature targets.

Campaign for 50% reduction by 2023 of greenhouse gas emissions from Swedish universities (including flight emissions) by university researchers (Alvesson et al. 2018) and students (Bernholz et al. 2019)

Note: These interventions are suggested for policy experiments to raise public awareness and support for, as well as catalyze individual and collective action toward, behavior change in line with meeting climate targets.

Sources: Classifications adapted from Osbaldiston and Schott (2012), with examples in better-studied domains taken from Wynes et al. (2018).

References

Abrahamse, W., L. Steg, C. Vlek, and T. Rothengatter. 2005. “A Review of Intervention Studies Aimed at Household Energy Conservation.” Journal of Environmental Psychology 25 (3): 273–91.

Abrahamse, W., L. Steg, C. Vlek, and T. Rothengatter. 2007. “The Effect of Tailored Information, Goal Setting, and Tailored Feedback on Household Energy Use, Energy-Related Behaviors, and Behavioral Antecedents.” Journal of Environmental Psychology 27 (4): 265–76.

Allcott, H. 2011. “Social Norms and Energy Conservation.” Journal of Public Economics 95 (9–10): 1082–95.

Alvesson, MA, et al. 28 October 2018. ”Universiteten måste själva börja klimatomställningen.” [Universities must start the climate transformation ourselves.] Op-ed in Dagens Nyheter newspaper. https://www.dn.se/debatt/universiteten-maste-sjalva-borja-klimatomstallningen/ (related petition available from Nordblad, J. et al., 2019, https://www.skrivunder.com/signatures/dags_for_universiteten_att_starta_klimatomstallningen/)

aningslosainfluencers. 2019. Social media account “Clueless Influencers.” “Aningslösa Influencers.” https://www.instagram.com/aningslosainfluencers/.

Bajželj, B., K.S. Richards, J.M. Allwood, P. Smith, J.S. Dennis, E. Curmi, et al. 2014. “Importance of Food-Demand Management for Climate Mitigation.” Nature Climate Change 4 (10): 924.

Bernholtz, A., Larsson, F., Hasselqvist, H., and W. Wanecek. 2019. “The students of Lund University demand a 50% reduction of LU’s emissions within 4 years.”   https://klimatuppropetlund.se/english.html

Bows-Larkin, A. 2015. “All Adrift: Aviation, Shipping, and Climate Change Policy.” Climate Policy 15 (6): 681–702.

Bows-Larkin, A., and K. Anderson.  2013. “Carbon Budgets for Aviation or Gamble with Our Future?” In Sustainable Aviation Futures, 65-84. Bingley, UK: Emerald Group.

Brunner, F., V. Kurz, D. Bryngelsson, and F. Hedenus. 2018. “Carbon Label at a University Restaurant: Label Implementation and Evaluation.” Ecological Economics 146: 658–67.

Byerly, H., A. Balmford, P.J. Ferraro, C.H. Wagner, E. Palchak, S. Polasky, et al. 2018. “Nudging Pro‐environmental Behavior: Evidence and Opportunities.” Frontiers in Ecology and the Environment 16 (3): 159–68.

Cames, M., J. Graichen, A. Siemons, and V. Cook. 2015. “Emission Reduction Targets for International Aviation and Shipping.” Brussels: Policy Department A: Economic and Scientific Policy, European Parliament.

Carfora, V., D. Caso, M. Conner. 2017. “Correlational Study and Randomised Controlled Trial for Understanding and Changing Red Meat Consumption: The Role of Eating Identities.” Social Science and Medicine 175: 244–52.

Carroll, J., S. Lyons, and E. Denny. 2014. “Reducing Household Electricity Demand through Smart Metering: The Role of Improved Information about Energy Saving.” Energy Economics 45: 234–43.

CDC (Centers for Disease Control). 2014. Best Practices for Comprehensive Tobacco Control Programs, 2014. Atlanta: U.S. Department of Health and Human Services.

Centola, D., J. Becker, D. Brackbill, and A. Baronchelli. 2018. “Experimental Evidence for Tipping Points in Social Convention.” Science 360 (6393): 1116–19.

Creutzig, F., B. Fernandez, H. Haberl, R. Khosla, Y. Mulugetta, and K.C. Seto. 2016. “Beyond Technology: Demand-Side Solutions for Climate Change Mitigation.” Annual Review of Environment and Resources 41: 173–98.

Davenport, T.C., A.S. Gerber, D.P. Green, C.W. Larimer, C.B. Mann, and C. Panagopoulos. 2010. “The Enduring Effects of Social Pressure: Tracking Campaign Experiments over a Series of Elections.” Political Behavior 32 (3): 423–30.

De Boer, J., A. de Witt, and H. Aiking. 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.

Delmas, M.A., and N. Lessem. 2014. “Saving Power to Conserve Your Reputation? The Effectiveness of Private versus Public Information.” Journal of Environmental Economics and Management 67 (3): 353–70.

Emory, K.T., K. Messer, L. Vera, N. Ojeda, J.P. Elder, P. Usita, et al. 2015. “Receptivity to Cigarette and Tobacco Control Messages and Adolescent Smoking Initiation.” Tobacco Control 24 (3): 281–84.

Francart, N., T. Malmqvist, and P. Hagbert. 2018. “Climate Target Fulfilment in Scenarios for a Sustainable Swedish Built Environment beyond Growth.” Futures 98: 1–18.

Friis, R., L.R. Skov, A. Olsen, K.M. Appleton, L. Saulais, C. Dinnella, et al. 2017. “Comparison of Three Nudge Interventions (Priming, Default Option, and Perceived Variety) to Promote Vegetable Consumption in a Self-Service Buffet Setting.” PLoS One 12 (5): e0176028.

Girod, B., D.P. Van Vuuren, and E.G. Hertwich. 2013. “Global Climate Targets and Future Consumption Level: An Evaluation of the Required GHG Intensity.” Environmental Research Letters 8 (1): 014016.

Gössling, S., F. Fichert, and P. Forsyth. 2017. “Subsidies in Aviation.” Sustainability 9 (8): 1295.

Hardt, L., P. Brockway, P. Taylor, J. Barrett, R. Gross, and P. Heptonstall. 2019. “Modelling Demand-Side Energy Policies for Climate Change Mitigation in the UK.” London: UK Energy Research Centre.

Hedenus, F., S. Wirsenius, and D.A. Johansson.  2014. “The Importance of Reduced Meat and Dairy Consumption for Meeting Stringent Climate Change Targets.” Climatic Change 124 (1–2): 79–91.

Hertwich, E., and G. Peters. 2009. “Carbon Footprint of Nations: A Global, Trade-Linked Analysis.” Environmental Science and Technology 43: 6414–20.

Institute for Global Environmental Strategies, Aalto University, and D-mat Ltd. 2019. 1.5-Degree Lifestyles: Targets and Options for Reducing Lifestyle Carbon Footprints. Technical report. Hayama, Japan: Institute for Global Environmental Strategies.

Karlsson, J.O., G. Carlsson, M. Lindberg, T. Sjunnestrand, and E. Röös. 2018. “Designing a Future Food Vision for the Nordics through a Participatory Modeling Approach.” Agronomy for Sustainable Development 38 (6): 59.

Klimatsmart Semester.[Climate-smart holiday] 2019. Climate calculator for holidays, holiday planning tips, and research on sustainable tourism. https://www.klimatsmartsemester.se/

Lenzen, M., Y.-Y. Sun, F. Faturay, Y.-P. Ting, A. Geschke, and A. Malik. 2018. “The Carbon Footprint of Global Tourism.” Nature Climate Change 8 (6): 522–28.

Le Quéré, C., R.M. Andrew, P. Friedlingstein, S. Sitch, J. Pongratz, A.C. Manning, et al. 2018. “Global Carbon Budget 2018.” Earth System Science Data Discussions 10: 2141-2194.

Levy, D.T., A. Hyland, C. Higbee, L. Remer, and C. Compton. 2007. “The Role of Public Policies in Reducing Smoking Prevalence in California: Results from the California Tobacco Policy Simulation Model.” Health Policy 82 (2): 167–85.

Masson-Delmotte, V., P. Zhai, H. O. Pörtner, D. Roberts, J. Skea, P. Shukla, et al. 2018. Global Warming of 1.5°C: An IPCC Special Report on the Impacts of Global Warming of 1.5°C above Pre-industrial Levels and Related Global Greenhouse Gas Emission Pathways, in the Context of Strengthening the Global Response to the Threat of Climate Change, Sustainable Development, and Efforts to Eradicate Poverty. Edited by IPCC. Geneva: World Meteorological Organization.

Murray, L. 2019. “Public Attitudes to Tackling Aviation’s Climate Change Impacts.” 10:10 Climate Action, January.

Naturvårdsverket [Swedish Environmental Protection Agency]. 2018. “Resultat för Klimatklivet [Results for Climate Leap 2019].” Last updated December 17. https://www.naturvardsverket.se/Stod-i-miljoarbetet/Bidrag/Klimatklivet/Resultat-for-Klimatklivet/.

Osbaldiston, R., and J.P. Schott. 2012. “Environmental Sustainability and Behavioral Science: Meta-analysis of Proenvironmental Behavior Experiments.” Environment and Behavior 44 (2): 257–99.

Šćepanović, S., M. Warnier, and J.K. Nurminen. 2017. “The Role of Context in Residential Energy Interventions: A Meta Review.” Renewable and Sustainable Energy Reviews 77: 1146–68.

Schäfer, A.W., S.R.H. Barrett, K. Doyme, L.M. Dray, A.R. Gnadt, R. Self, et al. 2018. “Technological, Economic and Environmental Prospects of All-Electric Aircraft.” Nature Energy 4: 160–66.  

Shoup, D.C. 1997. “Evaluating the Effects of Cashing Out Employer-Paid Parking: Eight Case Studies.” Transport Policy 4 (4): 201–16.

Sintov, N., E. Dux, A. Tran, M. Orosz. 2016.  “What Goes on behind Closed Doors? How College Dormitory Residents Change to Save Energy during a Competition-Based Energy Reduction Intervention.” International Journal of Sustainability in Higher Education 17 (4): 451–70.

Tertoolen, G., D. Van Kreveld, and B. Verstraten. 1998. “Psychological Resistance against Attempts to Reduce Private Car Use.” Transportation Research Part A: Policy and Practice 32 (3): 171–81.

Tyndall Centre. 2019. Tyndall Travel Strategy: Towards a Culture of Low-Carbon Travel for the 21st Century. Norwich, UK: Tyndall Centre for Climate Change Research.

von Arnold, Cecilia. 2018. “LUCSUS Presents New Travel Policy to Reduce Work-Related Emissions.” Lund University Centre for Sustainability Studies (LUCSUS), December 11. https://www.lucsus.lu.se/article/lucsus-presents-new-travel-policy-to-reduce-work-related-emissions.

Westlake, S. 2017. “A Counter-narrative to Carbon Supremacy: Do Leaders Who Give Up Flying Because of Climate Change Influence the Attitudes and Behaviour of Others?” SSRN, October 2.

Wynes, S., and K. A. Nicholas. 2017. “The Climate Mitigation Gap: Education and Government Recommendations Miss the Most Effective Individual Actions.” Environmental Research Letters 12: 074024.

Wynes, S., and S. D. Donner. 2018. “Addressing Greenhouse Gas Emissions from Business-Related Air Travel at Public Institutions: A Case Study of the University of British Columbia.” Pacific Institute for Climate Solutions Report. Available from https://pics.uvic.ca/sites/default/files/AirTravelWP_FINAL.pdf

Wynes, S., K.A. Nicholas, J. Zhao, and S.D. Donner. 2018. “Measuring What Works: Quantifying Greenhouse Gas Emissions Reductions of Behavioural Interventions to Reduce Driving, Meat Consumption, and Household Energy Use.” Environmental Research Letters 13: 113002.

The authors gratefully acknowledge helpful comments from Kevin Anderson, Jonas Sonnenschein, and Juan Diego Martinez, which greatly improved an earlier version of this document. All the interpretations and findings set forth in this expert perspective are those of the authors alone.