Modelling energy demand and CO₂ emissions associated with changes in household consumption patterns. A macro-micro long-term analysis based on time use

Household energy consumption represents a significant share of final energy use, especially when both direct and embodied energy are taken into account. Several academic studies, as well as the recommendations of the United Nations and of non-governmental organisations, suggest that a shift in consumption patterns will be necessary to achieve sustainable development. The aim of our research is to analyse long-term scenarios of changes in lifestyle. We propose a methodology that allows to analyse the macro-economic impacts of these changes, as well as the impacts on energy use and CO₂ emissions, while taking into account the heterogeneity of behaviours and energy consumptions among households. Consumption choices do not derive solely from monetary considerations but they are influenced by several factors. One binding constraint, never taken into account in macro-economic energy modelling, is the available time. For this reason, our analysis considers time use data in addition to expenditure and energy use data. We build a data base that combines time use, expenditure and energy consumption data for French households, which provides detailed information about household consumption patterns. Then, for scenario analyses, we link the data base with an Energy-Economy- Emissions model, using an iteration process based on a reweighting technique. We illustrate the methodology by exploring three areas of change in consumption patterns: cooking habits, e-commerce and shared transport (carpooling and car sharing). We obtain CO₂ emissions reductions in all scenarios. As an example, emissions decrease by 2.3% by 2050 in the scenario focusing on transport. (author)