The human dimensions of a sustainable energy transition

Global climate change poses a major threat to the health, economic prospects, and basic food and water sources of billions of people (IPCC, 2014). Negative effects of global climate change are already occurring, such as extreme weather events and reductions in global food supply (IPCC, 2014). Future effects will be even more severe. Global climate change is caused by the emission of greenhouse gasses, which have steadily increased by about 1.5 times between 1990 and 2008 (Boden, Marland & Andres, 2012). CO2 is the most important greenhouse gas, responsible for about 84% of the total emissions of greenhouse gases (EPA, 2004). Global climate change and environmental decline are largely caused by human behaviour and can thus be altered when people more consistently engage in sustainable energy behaviour (Dietz, Gardner, Gilligan, Stern, & Vandenbergh, 2009; IPCC, 2014; Pawlik & Steg, 2013). The main human activity that emits CO2 is the combustion of fossil fuels for energy and transportation. In this paper, we focus on household energy behaviour. Given the urgency of combating anthropogenic climate change, and the fundamental changes needed to realise a sustainable energy transition, substantial modification of a wide range of household energy behaviour is needed. These include the adoption of sustainable energy sources and technologies, the adoption of energy efficiency measures in buildings, the adoption of energy-efficient appliances, and changing user behaviour to reduce total energy demand and to match energy demand to available supply of (renewable) energy carriers. Achieving these wide-scale changes in behaviour requires a prominent role of social scientists in understanding how to motivate and enable people to actively contribute to a sustainable energy transition (Hackmann et al., 2014; Sovacool, 2014; Weaver et al., 2014; ISSC and UNESCO, 2013). Social scientists can study which factors cause sustainable and unsustainable energy behaviour, and examine how these factors can be addressed in energy policy and energy system changes. Besides, social scientists can study which factors determine the effectiveness and acceptability of energy system changes and policies aimed at promoting a sustainable energy transition.In this article, we review the contribution of social and environmental psychology in understanding and promoting sustainable energy behaviour by individuals and households. We propose a general framework, comprising four key issues:

1. identification and measurement of behaviours to be changed,
2. examination of the main factors underlying energy behaviour, including the adoption of sustainable energy resources and energy-efficient technology, investments in energy efficiency measures in buildings, and user behaviour,
3. designing and testing interventions to change behaviour that reduces CO2 emissions by households, including information, incentives, regulations and technological changes,
4. studying factors underlying public acceptability of interventions and changes in energy systems.

We discuss important findings from psychological studies on these four topics and propose a research agenda for further exploration of these topics. In doing so, we will demonstrate that many studies follow a narrow approach, by studying specific antecedents of single energy behaviours or effects and acceptability of specific policies. We emphasise the need of an integrated approach in studying the human dimensions of energy problems that increase our understanding of which general factors affect a wide range of energy behaviours as well as the acceptability of different energy policies and energy system changes.

Which behaviour changes are needed to promote a sustainable energy transition?

A sustainable energy transition implies that future energy systems will more strongly rely on renewable energy sources, such as solar or wind energy. Hence, to realise sustainable energy transitions, we need to understand if individuals are willing to accept and adopt renewable energy sources. Besides, to enhance the efficiency of sustainable energy systems and to meet energy demands of individuals and households across the world, total energy demand needs to be reduced, at least in developed countries. For this purpose, individuals can invest in energy efficiency, such as refurbishment of houses and adoption of energy-efficient appliances. Also, they can change their daily energy behaviours, such as reducing thermostat settings or showering time. Moreover, given that the production of energy from renewable resources may strongly vary with weather conditions, renewables are not always readily available. Hence, individuals may need to balance their energy demand to the available supply of energy produced from renewable resources. Balancing energy demand and supply can be realised by shifting energy use in time, either autonomously or by installing technologies that automatically switch on or off specific appliances on the basis of the available energy supply. In addition, people could adopt storage facilities such as batteries and electric cars.From a practical point of view, studies should ideally focus on behaviours that have an important impact on total energy use and CO2 emissions, such as the adoption of renewable energy sources, home insulation, or space heating (Abrahamse, Steg, Vlek, & Rothengatter, 2007; Dietz et al., 2009). Households use energy not only in a direct way, for example by using gas or electricity for cooking and heating, but also in an indirect way (Kok, Benders, & Moll, 2006; Vringer & Blok, 1995). Indirect energy use refers to the energy requirement of the production, transportation and disposal of goods and services used by households. In European countries, about half of total household energy use reflects direct energy use, while the other half is related to indirect energy use (Kok, Falkema, Benders, Mill, & Noorman, 2003; Reinders, Vringer, & Blok, 2003). Yet, only few studies examined factors underlying behaviour related to indirect energy use (Abrahamse, Steg, Vlek, & Rothengatter, 2007; Gatersleben, Steg, & Vlek, 2002; Poortinga, Steg, Vlek & Wiersma, 2003). Environmental scientists have developed various tools for assessing direct and indirect energy use, such as life-cycle analysis, and input-output analysis (e.g., Kok et al., 2006) that are useful for identifying behaviours associated with relatively high levels of indirect energy use, that can help psychologists to identify high impact behaviours to be studied.As yet, different types of energy behaviours are typically studied in isolation. For example, studies have examined the adoption of renewable energy sources such as solar or wind energy (see Perlaviciute & Steg, 2014, for a review), investment in specific energy efficiency technologies such as electric vehicles (Bockarjova & Steg, 2014; Klöckner, 2014; Noppers, Keizer, Bolderdijk, & Steg, 2014; Schuitema, Anable, Skippon & Kinnear, 2013) or energy efficient light bulbs (Lee, Park, & Han, 2013; Reynolds, DeSisto, Murray, & Kolodinsky, 2007), the adoption and use of specific components of smart grids (Sintov & Schultz, under review), and specific energy behaviours such as doing your laundry (McCalley & Midden, 2002) or showering (Aronson & O’Leary, 1982-83). An important question, however, is how these different types of behaviours are related, and how broader lifestyle effects can be realised, including, for example, adoption of renewable energy sources and energy-efficient technologies, changes in everyday energy behaviour, investments in refurbishments, and acceptability of energy policy. A key issue here is whether and under which conditions engagement in one type of sustainable energy behaviour is likely to spill over to other behaviours (Truelove, Carrico, Weber, Raimi, & Vandenbergh, 2014). On the one hand, some studies have found evidence of negative spillover in the environmental domain (Thøgersen & Ölander, 2003; Tiefenbeck, Staake, Roth, & Sachs, 2013). For example, people were more likely to increase their energy consumption after reducing their water use (Tiefenbeck et al., 2013), and they were less likely to recycle their waste after buying organic products (Thøgersen & Ölander, 2003). Research suggests that so-called compensatory green beliefs, reflecting the extent to which individuals think that engagement in one sustainable behaviour legitimates not acting sustainably in another occasion, may inhibit durable sustainable energy behaviour, and hence result in negative spillover effects (Kaklamanou, Jones, Webb, & Walker, 2015). Yet, literature suggests that such negative spillover (or rebound) effects may be small (Blanken, Van de Ven, & Zeelenberg, 2015; Gillingham, Kotchen, Rapson, & Wagner, 2013) and generally not fully offset the efficiency gains of the initial measure (Barker, Dagoumas, & Rubin, 2009; Frondel, Ritter, & Vance, 2012). Still, little is known about how we can prevent that sustainable energy actions lead to negative spillover or ‘rebound’ effects.On the other hand, several studies have found positive spillover effects (Thøgersen & Ölander, 2003; Lanzini & Thøgersen, 2014). For example, those who recycled were more likely to buy organic food and use environmentally-friendly modes of transport one and two years later (Thøgersen & Ölander, 2003). Also, an increase in green buying following an intervention promoted subsequent recycling, the use of public transport, car-pooling, printing on both sides, saving water, and switching off lights (Lanzini & Thøgersen, 2014). Research suggests that such positive spillover effects are more likely when people relate the initial sustainable energy behaviours to themselves, thereby strengthening their environmental or energy-saving self-identity (Van der Werff, Steg, & Keizer, 2013, 2014a, 2014b). More particularly, when people realise they engaged in sustainable energy behaviours (or more generally pro-environmental behaviours), they are more likely to see themselves as a pro-environmental person, which motivates them to act in line with this identity in subsequent situations. The question remains, however, how stable positive spillover effects are, as long- term effects have typically not been considered. We come back to this issue in the coming steps of this week.