Great potential for changing behaviour

A new diet is one of the most effective ways to reduce greenhouse gas emissions. Photo: Mait Jüriado/ / CC BY-NC-SA

With a policy package that motivates citizens to take up a more healthy diet, replace their fossil fuel cars with electric cars and decrease room temperature, emissions in the EU could be reduced by about a quarter of the projections for the non-ETS sector by 2020.

Behavioural change is a relatively neglected area in climate change mitigation, but has a huge potential according to a new report, Behavioural Climate Change Mitigation Options, commissioned by the European Commission. The authors focus on emissions from household heating, transport and food, and identified 36 options for behavioural change that can lead to emission reductions within these areas. Based on existing barriers that discourage citizens from making specific behavioural changes and the scope for policy interventions to reduce these barriers, the mitigation potential of eleven of these options was assessed (table).

Table. Maximum realistic mitigation potential of behavioural changes in million tonnes CO2 equivalents, relative to PRIMES/GAINS EU-27 reference scenario projections.

Note: The maximum realistic mitigation potential is defined as the reduc- tion in GHG emissions achieved when the option is adopted by the largest number of people possible, taking into account realistic and structural constraints, and where possible indirect effects and rebound effects.

A shift to a vegetarian diet was found to have the highest potential by 2020. But a change to a healthier diet with fewer calories and more fruit and greens has almost as high a potential. The option of buying an electric car has a lower mitigation potential in the shorter term, but could have a greater effect by 2050, since behavioural barriers are expected to significantly decrease over time. A lowering of the room temperature by two degrees had the highest potential among the household heating options, but that potential would be reduced over time since more housing is expected to get improved insulation over the years.

All these measures can not be implemented simultaneously. The maximum possible common reduction potential is approximately 600 million tonnes of CO2 equivalents in 2020, which is about a quarter of the projected emissions in 2020.

Food accounts for a considerable amount of greenhouse gases generated from EU citizens’ consumption, half of which can be attributed to meat production. All three options examined result in reduced meat consumption, although in different contexts and scope:

  • Shift to a vegetarian diet (no meat, fish or seafood, but still milk and diary products)
  • Reduced animal protein (14% less consumption of all animal-derived products, which equals one vegan day a week)
  • Shift to a healthy diet (according to WHO recommendation, a maximum of 2,500 calories a day, and eating 500g of fruit and vegetables).

Cultural barriers are believed to be hard to overcome in encouraging EU citizens to switch to the first two diets. Over large parts of the continent there is a widespread perception that meat must be included in every meal. This attitude is supported by dietary habits, which were identified as another strong factor in peoples’ choice of food. Lack of knowledge about the environmental impact of meat is also believed to be a problem. On the other hand there are no economic barriers to change, since all three diets are cheaper than the average diet today. School initiatives and a taxation scheme on animal products are considered to be the most effective methods to motivate people to reduce their consumption of animal protein or shift to a vegetarian diet. Media campaigns and labelling are also suggested methods.

Motivating people to shift to a healthy diet is considered to be less challenging when it comes to cultural beliefs. Being fit and healthy are strong elements in modern consumer culture, but this may be partly offset by more traditional views, in which food with a high calorie content is highly valued. There is also a quite widespread awareness about the benefits of eating healthily. In common with the other two diets, the healthy diet is also cheaper than the conventional diet, although it may be perceived as more expensive. Junk food usually has a low cost per calorie, which is often considered as good value by consumers. Fruit and vegetables on the other hand have a rather high price per calorie and are often ruled out by customers with a more limited budget. Another more general problem is the great abundance of unhealthy food in our society. So even though there is no real lack of healthy foods on supermarket shelves, many people encounter far too many unhealthy alternatives in a day to easily maintain a healthy diet. To persuade Europeans to decrease their energy intake and at the same time eat more fruit and greens, a multiple approach is suggested with consumption taxes on unhealthy food, improved food labelling and school initiatives.

In the transport sector, modal shifts from car to train, bicycle or by foot – although having great potential – were not examined closer since there already exists a wide range of studies on this topic. The four behavioural changes that were scrutinised, because of their potential and availability of adequate background research, were:

  • Buying and using a plug-in hybrid or an electric car
  • Buying and using a smaller car
  • Adopting a fuel-efficient driving style
  • Teleworking and switching to virtual meetings.

The main barriers for the first two options were found to be somewhat similar. Car owners are generally very concerned about the perceived social status of their cars. In one study it was shown that the single most important factor for the choice of car brand was which brand near neighbours had bought recently. Small cars are generally associated with a lower status than large vehicles. Electric cars and plug-in hybrids are unusual and can be perceived as a bit odd, however there is also a segment of customers that would buy an electric car because it fits well with their image. A connected problem is that there are still very few models of electric cars, which limits the possibility for expressing individuality.

There are also trade-offs in comfort. Small cars cannot carry as much as bigger models and owners might need to use home delivery when purchasing bulky items or rent a bigger car for holidays. Electric cars need to be charged and this will influence driving and parking patterns. There is also a considerable economic barrier for electric cars, since they are still much more expensive than conventional cars. It is believed that other types of business models will develop for electric cars, such as leasing the battery, which is the single most expensive component of an electric car.

Information campaigns and economic incentives for consumers are proposed as possible ways of dealing with these barriers, as well as various types of initiatives aimed at manufactures and resellers to improve the range of models available. The authors also highlight the need to develop an electricity charging infrastructure if citizens are to invest in electric cars and plug-in hybrids.

The greatest barriers to encouraging people to adopt more fuel-efficient driving styles are believed to be habits and lack of knowledge. This measure is believed to be less important over time since future models are expected to be equipped with technology that automatically leads to more fuel-efficient driving.

In the case of teleworking, the authors found that employees are worried about losing career opportunities and about social isolation, while employers worry about losing control. A regulatory framework for the employment conditions of teleworkers as well as increasing the cost of commuting are suggested as ways forward. Higher fuel prices are actually a measure that is suggested to encourage all four transport-related types of behavioural change that were studied.

To reduce emissions from the heating of houses the following types of behavioural change were considered:

  • Lowering room temperature by 1 or 2 degrees.
  • Optimising heating thermostat settings (e.g. leaving room temperatures at the same level, reducing temperature at night/if absent).
  • Optimising ventilation behaviour.

Increasing awareness of household energy consumption is believed to be a key step in improving energy-saving behaviour. Underestimations of individual household consumption are very common and lead to a false perception that it is others who need to change. Economic incentives are also mentioned, and in this context the authors also address the issue that the change in behaviour only persists as long as the tax or subsidy is around. There can also be negative rebound effects in related areas, for example if taxes for heating are increased while those for electricity are not, this might encourage people to use more electricity.

This report, which does not claim to be a comprehensive review, only deals with a handful among thousands of possible behavioural changes that could contribute to a more sustainable Europe, but it clearly indicates that changes in behaviour must increasingly be set as political objectives and followed up with the policy measures that are needed to realise them.

Kajsa Lindqvist

Behavioural Climate Change Mitigation Options and Their Appropriate Inclusion in Quantitative Longer Term Policy Scenarios, CE Delft, 2012,

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