Modeling the energy/carbon impacts of lifestyle changes. A macro-micro prospective based on time use.

Summary Households are responsible for a significant share of energy consumption and CO2 emissions, especially if we take into account energy consumption and indirect emissions related to the production processes of goods and services consumed. Several scientific works and recommendations of governmental and non-governmental organizations underline that changes in consumption patterns will probably be necessary to reach the climate objectives set today. Our thesis proposes a method of prospective analysis of lifestyle changes, which allows us to estimate the macro-economic impacts as well as those on energy consumption and CO2 emissions, while taking into account the heterogeneity of households in terms of behavior and energy consumption. Our method explores the consumption patterns of households in a detailed way, taking into account the link between time use and consumption. Indeed, consumption choices are subject not only to budget constraints, but also to time constraints that are never taken into account in macroeconomic forecasting. We build a database detailing the time use, expenditure and energy consumption of French households and we link it to an economic energy-emissions forecasting model through an iterative reweighting process. We illustrate the scope of this tool through the analysis of three scenarios, centered respectively on the diffusion of new forms of mobility (carpooling and carsharing), the generalization of online shopping and the return to do-it-yourself food. For all three scenarios we observe reductions in energy consumption and CO2 emissions. For example, total emissions decrease by 2.3% in 2050 in the mobility scenario.