Soutenance de thèse : Célia Escribe

Abstract

Addressing climate change requires the coordination of different mitigation options, including energy supply decarbonization, end-use low-carbon technology adoption, efficiency, and sufficiency. These mitigation actions may involve complex sectoral interactions and rely on decision-making by heterogeneous agents. There is a critical need to better understand the required portfolio of mitigation actions to achieve ambitious climate targets and to design effective policy instruments that ensure these decarbonization pathways are attainable. This thesis explores how integrating sectoral interactions and heterogeneous agents into economic models shapes the role of the different climate change mitigation channels, and how it influences the choice of policy instruments.

In the first chapter, we explore the optimal allocation of mitigation strategies in the residential sector, including insulating homes, switching to low-carbon heating systems, and decarbonizing energy carriers. We develop an innovative framework that is both technology-explicit and behaviorally rich, and we demonstrate the critical role of subsidy specifications and supply-side assumptions in determining the trade-offs between mitigation options. In the second chapter, we rely on the same modeling framework to assess the implications of enacting a ban on new fossil fuel boilers, focusing on France as a case study. We find that heat pump adoption shifts gas use from heating demand to electricity generation, which is a more efficient use of low-carbon biogas from a whole-system perspective. As a ban on new gas boilers achieves widespread heat pump adoption more effectively than incentives under uncertainty, we show that such a ban is critical to achieve carbon neutrality. In the third chapter, we examine the role of heterogeneity in shaping long-term investment strategies for renewable producers in perfectly competitive markets, where risk-averse agents make decisions amid significant uncertainties. We develop a stylized mean field game model, and we demonstrate that the outcomes derived from the model cannot be replicated by simpler models that use a representative agent. Finally, in the fourth chapter, we explore the economy-wide consequences of sufficiency by developing a static macroeconomic model that integrates a detailed microeconomic production framework. We show that the mitigation potential of sufficiency is contingent on the underlying economic production network and on elasticities of substitution, and we demonstrate significant rebound effects compared to estimates from input-output models without behavioral aspects.