Limiting global warming below 1.5 °C requires rapid decarbonization of energy systems. Reductions of energy demand have an important role to play in a sustainable energy transition. Here we explore the extent to which the emergence of low energy consuming practices, encompassing new behaviors and the adoption of more efficient technologies, could contribute to lowering energy demand and thereby to reducing CO2 emissions. To this end, we design three detailed energy consumption profiles which could be adopted by individuals in current and future wealthy regions. To what extent does the setting of air conditioners to higher temperatures or the widespread use of efficient showerheads reduce the aggregate energy demand? We investigate the potential of new practices at the global level for 2050 and 2100. The adoption of new, energy saving practices could reduce global energy demand from buildings by up to 47% in 2050 and 61% in 2100 compared to a scenario following current trends. This strong reduction is primarily accounted for by changes in hot water usage, insulation of buildings and consumer choices in air conditioners and heat pumps. New behaviors and efficient technologies could make a significant long-term contribution to reducing buildings’ energy demand, and thus facilitate the achieval of stringent climate change mitigation targets while limiting the adverse sustainability impacts from the energy supply system.

Introduction

Limiting global warming in line with the Paris Climate Agreement poses a great challenge to socio-economic structures across the world. On the one hand, geophysical studies revealed a proportional relationship between cumulative CO2 emissions and temperature increases (Matthews et al., 2009), which means that staying below 1.5 °C global warming requires cumulated emissions to remain within a tight carbon budget (Rogelj et al., 2016). Carbon neutrality must therefore be reached by mid-century (Rogelj et al., 2015). On the other hand, the pace of emission reductions necessary for remaining below 2 °C, and a fortiori below 1.5 °C global warming, resembles only few examples in history (Riahi et al., 2015) and is unprecedented on a global scale. Energy consumption in buildings accounted for 23% of energy-related CO2 emissions in 2014 (Rogelj et al., 2018). These emissions resulted from both direct emissions released by on-site combustion of fossil fuels and biomass (8%), as well as from indirect emissions attributed to electricity consumption in buildings and district heating (15%). Reducing energy demand in buildings therefore constitutes an important strategy to decrease GHG emissions. Many studies appraised the global potential for reduction of the energy consumed in buildings. Overall, they found this potential to be substantial (Lucon et al., 2014). However, these studies usually assessed the potential as a result of technological changes, leaving aside the impact of behavioral changes (e.g. Chaturvedi et al., 2014; IEA, 2016; Teske et al., 2015). Some other studies investigated the energy demand reduction potential following changes in lifestyles, while excluding technological changes. Thereby, these studies implied a dichotomy between technological and behavioral solutions (e.g. van Sluisveld et al., 2016; Ven et al., 2017).