'Bridging’ human needs and carbon dioxide emissions reduction : the infrastructure dynamics at the core of the climate-development interplay.

Summary Human development and climate change mitigation issues are linked and infrastructure - buildings and civil engineering structures - are essential to achieve these objectives together. They provide services that meet societal needs, but this provision is currently insufficient and intensive in terms of CO2 emissions in their use and construction. However, their dynamics are subject to technical, economic and institutional constraints. In this thesis, I investigate how the evolution of global infrastructure stocks can reconcile development needs with CO2 emission reductions. I focus on three points of tension: (i) carbon lock-in - the inertia on future emissions reduction - induced by short-term development, (ii) limited financing for investment, and (iii) the carbon space for sufficient development of basic infrastructure. This thesis makes a contribution by highlighting some of the conditions that need to be ensured for infrastructure not to limit the feasibility of climate-development reconciliation.First, I conduct a systematic review of the literature on infrastructure-induced carbon lock-in. I use a supervised machine learning approach to select relevant articles. I synthesize by sector and geography existing quantifications of carbon lock-in, indicators used to measure it, and statements mentioning policy implications for exiting it. I show that coal-fired power plants contribute significantly to global carbon lock-in and are at risk of stranded assets due to early retirement. [...] There is a need to ensure their long-term legitimacy and stability as well as coordination across infrastructure sectors. Carbon pricing should not be the only instrument used and should be complemented by regulation and financial support for the deployment of low-carbon capital.Next, I quantify transport infrastructure investment needs with respect to different levels of climate ambition. I build socio-economic scenarios with an integrated assessment model that explicitly represents the transportation sector. I develop a module to quantify the investment needs consistent with the mobility scenarios. I apply a global sensitivity analysis to identify the determinants of the investment needs. I show that investment needs are reduced with increasing climate ambition but represent significant amounts compared to historical levels and to needs in other sectors. Finally, I assess whether a high level of access to 5 essential services - electricity, water, housing, sanitation and transport - can be provided globally without compromising climate mitigation goals. I quantify the cement and steel requirements in each country based on historical trends. I then estimate the CO2 emissions associated with the manufacture of these materials by incorporating influencing factors such as production technologies, international trade patterns, and mitigation measures in these industries. I show that providing high access to sanitation and transportation can conflict with the low-carbon trajectories envisioned. These results suggest the need for limitations on the use of cement and steel and for additional emission reduction efforts in developed countries.