Technological solutions on their own are unlikely to deliver emissions reductions at the speed and scale required to reach net zero by 2050. Daniel Crow, Insa Handschuch, Gabriel Saive and Leonie Staas at the IEA look at a suite of policy-driven citizen “behaviour changes” that should be used to bridge the gap. The impact will be greatest in advanced economies where energy intensity is highest. Meanwhile, in emerging economies the good habits put in place now will steer them towards lower emissions even as their energy consumption grows. The authors describe changes to a wide range of areas – including transport, heating, product choices, recycling – and provide estimates of what emissions can be avoided. Success will also usefully reduce the demand for clean energy, already under pressure to scale up fast. They give plenty of examples of how governments have been using incentives, taxes and rules to effect behaviour change, citing the EU, the U.S., Japan, Germany, France, the UK, Scandinavia, Switzerland, Colombia, and Kenya. Public acceptance is essential, and though many measures may meet resistance at first, minds can be changed as the benefits become noticeable. People are always changing their behaviour – history and Covid tell us so – and ignoring this fact would be missing a huge opportunity to align that change with net-zero targets, say the authors.
Behavioural changes which affect the way people use energy are an important part of the toolkit for reaching net zero emissions by 2050.
The IEA’s Net Zero Emissions by 2050 Scenario (NZE) calls for profound transformations in every corner of the global energy system to achieve an energy sector that is both decarbonised and able to support a global economy twice the size of today’s in 2050. It sets out 400 milestones on deploying clean energy technologies and improving energy efficiency across all sectors.
But technology alone is not enough: net zero emissions in 2050 cannot happen without the consent and active support of people. In part, this involves one-off events that are not counted as behavioural changes but involve a mixture of low carbon technologies and people’s engagement, such as buying an electric vehicle (EV) or insulating a loft.
However, behavioural changes – meaning adjustments in everyday life that reduce wasteful or excessive energy consumption – are also needed. They are especially important in richer parts of the world where energy intensive lifestyles are the norm. Behavioural changes include cycling or walking instead of driving, turning down heating, and going on holiday nearer to home. In addition, efforts by manufactures to use materials more efficiently and encourage consumers to recycle can reduce energy use in industry.
People do change. History and Covid tell us so
Behavioural changes can and do happen. From diet to smoking to throw-away plastic packaging, past experience shows that people’s attitudes and habits are not set in stone. Most recently, the Covid-19 pandemic demonstrated that people are willing to adopt rapid and sweeping changes to their behaviour in the face of a crisis. The assumption that people’s lifestyles and patterns of consumption will continue unaltered in a scenario of net zero emissions by 2050 is arguably unrealistic, and risks ignoring the potential for individuals, via their choices and habits, to help steer the energy system onto a sustainable path.
What types of behavioural changes happen in the NZE scenario and how do they help?
In the NZE scenario, behavioural changes help cut emissions and reduce energy demand in buildings, on roads and in air traffic. Total CO2 emission in the NZE between 2021-2050 are around 4% less than they would be without such behavioural changes. They function in three main ways:
…Behavioural changes cut emissions from existing carbon intensive assets
Clean energy technologies are adopted at unprecedented speed in the NZE, but this cannot happen overnight.
Using carbon intensive assets such as gas boilers or internal combustion engine (ICE) cars less frequently or intensively offers a shortcut to rapid emissions reductions. For example, although 60% of car sales are electric vehicles by 2030 in the NZE, four-out-of-five cars on the road are still ICEs. In this scenario, behavioural changes such as driving more slowly on motorways and restricting use of conventional vehicles in large cities cuts CO2 emissions from road transport by 15% or 700 Mt in 2030 – roughly equivalent to all emissions from international shipping in 2019. In a similar vein, setting thermostats at no more than 19-20 °C in homes, offices and other commercial buildings in winter reduces cumulative emissions from the existing stock of fossil-fuelled boilers by 10% until 2030, allowing the time needed for clean-heating retrofits to take place1
Achieving the same emissions reductions in end-uses without such behavioural changes would require ramping-up low-carbon technologies at a staggering speed. For example, almost half of all cars on the road in 2030 would need to be electric, meaning that global sales of electric cars would need to reach almost 100% in the next five years, from around 4% today.
…Behavioural changes cut emissions in sectors where other options for doing so are scarce
By 2050 in the NZE, most end-uses are non-emitting as they have been electrified or make use of biofuels and low-carbon gases. In some sectors, however, low-carbon technologies are not well developed or are costly to deploy at scale. This is particularly true for aviation, where reducing business travel and long-haul holidays (over six hours flying time), predominantly in advanced economies, saves around 170 Mt CO2, or 40% of the remaining emissions from this sector in 2050.
More efficient design and construction of buildings and vehicles, as well as increased rates of recycling, also reduce emissions in industry, where some activities are hard to fully decarbonise. For example, in the chemicals sector, an increase in the recycling rate of plastics, mainly polyethylene terephthalate (PET) bottles, from around 17% today to over 50% in 2050, cutting emissions in 2050 by 13%.
…Behavioural changes reduce energy demand, taking pressure off new sources of low-carbon electricity and helping to keep biofuels production within sustainable limits
If behavioural changes were not to materialise, final energy use in the NZE would be around 16 EJ (5%) higher in 2050. The single biggest increase would be in electricity demand, which would be around 1,600 TWh, or around 3.5%, higher in 2050 (roughly equivalent to the combined renewable electricity generation of the European Union, Canada and Australia in 2019). Behavioural changes, particularly in the aviation sector, also reduce demand for modern bioenergy by 1.5 EJ, or 3%, in 2050, which corresponds to planting a land area roughly the size of Greece.
In different parts of the world, behavioural changes happen to different extents and are adopted at different speeds in the NZE. In part this reflects geographical and infrastructure constraints: for example, fully replacing regional flights with high-speed rail can take up to 30 years, reflecting the lead times of large publicly-funded infrastructure projects that may face political complications. But the scenario also takes into consideration existing behavioural norms, cultural preferences and prevailing views on environmental issues.2
In the NZE, behavioural changes reduce the number of kilometres driven by road vehicles in 2050 by about one-third in advanced economies, but only by 14% in emerging Asian economies. Similarly, a range of measures in aviation, such as reducing business travel, result in only slight growth in the number of passenger kilometres in advanced economies between 2019 and 2050, whereas emerging Asian economies and other developing economies see 200% and 150% growth respectively over the same period.
Because behavioural changes in the NZE are faster and deeper in advanced economies, they have the effect of flattening out the unequal distribution of per-capita energy consumption around the world. For example, moderating the use of space heating by setting the desired temperature to 19-20°C reduces electricity demand by 160 TWh globally in 2030, with over 70% of this reduction taking place in advanced economies. The impacts of behavioural changes in buildings and road transport on emissions are also largest in advanced economies, despite over 85% of activity growth between 2019 and 2050 occurring in emerging market economies.
Governments are key actors to enable behavioural changes
Even though behavioural changes can deliver important emissions reductions, often accompanied by individual and collective social and economic benefits, it can be difficult for individuals to change the way they use energy. Policy makers need to recognise the barriers to behavioural changes and put in place policies that make it easy for people to modify the way they use energy. There are several real-world examples of policies at both national and regional levels that inform, incentivise or sometimes mandate behavioural changes and consumer habits.
…clothing choices, for heating and cooling
Adapting social norms by raising awareness of climate change and its consequences can help save energy. For instance, since 2005 Japan has conducted the ‘Cool Biz’ campaign which promotes a casual, lighter office dress code in summer, thus reducing the need for air conditioning.
…energy labelling for appliances
Today, we often lack accessible and clear information on how our energy-related decisions impact the climate, which can lead to choices that are misaligned with collective sustainable energy goals. In some cases, policy makers can apply non-coercive, low-cost solutions that gently encourage more environmental choices. So-called nudges simplify decision making and are particularly well suited to reduce energy consumption of residential appliances. The European Union adopted energy labels for a wide range of appliances in 2010: a simple, highly visible coloured A to G scale enables consumers to easily understand the energy impacts of their purchase. The IEA estimates that this programme avoided more than 310 Mt CO2 (11%) of the EU’s energy-related emissions in 2019. A premium in the upfront cost of the most efficient appliances is often compensated by lower energy bills, allowing consumers to benefit financially. Consumer attitudes can also have an impact on investment decisions made by businesses to maintain their market share.
…”default” green electricity subscription
Sometimes, however, even being fully informed is not enough. When changing behaviour requires an effort, no matter how small, we tend to prefer to take no action. Policy makers can use this status quo bias to nudge energy consumers towards choosing the most environmentally friendly solution as an automatic choice. The right default option can trigger radical changes among consumers. A large-scale field study of electricity subscriptions in Switzerland3 found that setting a ‘green’ electricity package as a standard subscription increased the share of customers using exclusively renewable electricity from less than 5% to over 80%. This shift remained stable over several years, despite a higher price and the possibility to opt out and take a ‘classic’ energy bundle instead.
…incentives, subsidies and taxes
Financial incentives and price signals, such as subsidising climate conscious lifestyles and making emissions-intensive activities more costly, can help promote cleaner options. One example is residential heating, where consumers are discouraged by the high upfront cost of energy efficient solutions. To counteract this, in 2020 Germany adopted a scrapping bonus for old oil heaters, granting up to 45% of the investment costs of new, more efficient equipment. Within a year, more than 110,000 consumers applied to the programme, the majority planning to replace oil with heat pumps or biomass boilers. In the transport sector, urban road pricing schemes have been widely adopted. Originally implemented to tackle congestion or noise and air pollution, they are an effective instrument to decarbonise road transport. Making private use of ICEs in cities relatively more expensive and less convenient encourages a switch to other, cleaner transport modes. Policy makers can facilitate the change to public transport or active mobility with additional incentives. For instance, Colombia adopted a law that gives employees half a paid day off for every 30 times they cycle to office.
…public works, investment, rules
Importantly, incentives for switching transport modes must be combined with public investments. People will only drive less if they have convenient alternatives. Thus, the use of public transport and active mobility depends on the existence of metro lines, bus lanes and cycling infrastructure. In emerging market and developing economies, public investment in electricity access plays an important role to ensure the uptake of clean energy sources among residential and commercial consumers. For example, in 2018 Kenya adopted its strategy to reach universal and reliable access to electricity by 2022 with a focus on renewables, including off-grid photovoltaic (PV) systems. Since 2017, electricity access in Kenya has grown more than six percentage points a year to 70% in 2019, outpacing population growth.
The pathway to net zero 2050 is narrow, and voluntary actions, nudges or financial incentives will not be enough. Ultimately, consumers’ options will all need to be aligned with achieving a low-carbon pathway. This underscores the role of mandatory standards for appliances, buildings or vehicles, and for all private investments to become low-carbon over time. The US state of California adopted an ambitious set of building standards which require new constructions to integrate EV chargers and solar PV systems, thereby driving vehicle electrification and solar deployment all over the state. The US Department of Energy estimates that similar building codes on a national level could avoid about 900 Mt CO2 over a thirty year period. In the transport sector, mandatory policies can complement investments towards cleaner transport modes, like prohibiting domestic air routes when an alternative train takes less than two-and-a-half hours, as recently came into force in France.
Key policy options to enable behavioural changes and real-world examples
Effective behavioural interventions must be publicly accepted
All creative behavioural policies face one crucial condition to deliver: public acceptance. This is straightforward: behavioural measures will only reach full effectiveness if citizens fully support the policy goals and instruments. If citizens perceive the scheme’s impacts as socially unfair, acceptance collapses as was prominently demonstrated by the French “yellow vests’’ protests against gasoline taxes or the Norwegian “war on road tolls” movement.
The onus rests on governments to explain in a transparent manner not only how behavioural changes are essential to meet climate goals, but also to emphasise their many co-benefits, including improved health and well-being, cleaner air, less traffic congestion, cheaper fuel bills and even fewer road traffic injuries, as assessed in London after the introduction of Low Traffic Neighbourhoods in 2020. Policy makers can also enhance public support for behavioural interventions through so-called green earmarking – tying the use of additional revenues generated through a new behaviour policy to emissions-reducing activities.
In some cases government legislation must lead the way, with public support picking up later as the co-benefits of changes became apparent. Road pricing schemes are a prominent example. In many Scandinavian cities, public support for the measures initially fell when they were announced but acceptance strongly increased once individual benefits became noticeable.
Achieving net zero emissions by 2050 requires a profound transformation of the global energy system. But unintrusive, technological solutions on their own are unlikely to be enough to deliver emissions reductions at the speed and scale required. Behavioural changes are both necessary and achievable, and the onus is on governments to set the direction of those changes and enable them via effective and sustained policy support.
Daniel Crow is an Energy Modeller at the IEA
Insa Handschuch is an Energy and Environment Policy Analyst at the IEA
Gabriel Saive is a Data Management Co-ordinator, Environment and Climate Change at the IEA
Leonie Staas is a Junior Energy Modeller, Energy Demand Sectors at the IEA
- Behavioural changes consider current practices and behavioural norms. For example, motorway speeds are reduced only in countries where they exceed 100 km/h today; the reduction in space heating is aimed at curbing excessive energy use but continues to allow for variability between households according to individual preferences.
- World Value Survey, Wave 7: 2017 – 2020.
- Liebe, U. et al. (2021). “Large and persistent effects of green energy defaults in the household and business sectors”. Nature Human Behaviour Vol. 5.