Publications

To address the growing impacts of heatwaves on economic activities and populations, the adaptation of the building sector is becoming a new imperative. While the question of “how” to adapt has been the subject of numerous studies, the question of “how much” has so far received little attention. To move forward on this issue, we present in this report: an overview of current knowledge regarding the costs of adapting the building sector to heatwaves and the methodology we used to estimate the additional costs of adapting to heatwaves, based on available information and discussions with experts.

Assessing the economic implications of climate policies is essential for steering public action. Sig­nificant progress has been achieved in assessing the costs of mitigation, particularly with the publication in 2023 of the report on the economic implications of climate action. However, as the Cour des Comptes noted in its 2024 annual public report, numerous issues surrounding adaptation continue to emerge. Our recent work has nev­ertheless enabled us to draw five initial conclusions on the subject.

While French local authorities have important levers for adaptation, they will only be able to mobilize them if certain conditions are met at national level: the entire effort cannot rest on their initiative alone. This is what this I4CE's Climate Report shows. There is an urgent need for a discussion on adaptation between the national government and subnational authorities.

This study is a contribution to the French public debate. It aims at supporting the acceleration and concretization of climate change adaptation initiatives in this country. The study reviews 11 adaptation challenges such as the strengthening of civil protection, the reshaping of coastal areas or the protection of water resources. For each challenge, the study presents national budgetary decisions ready to make in the next Finance Bill that would complement existing actions and cost elements to feed the required arbitrations yet to be made.  

Over 35°C in exam halls during the French baccalaureate, inhabitants affected by their residences overheated… Summer 2022 has once again shown that our buildings aren’t adapted for the new heat waves. And yet every year, tens of billions of euros are invested in construction and renovation projects that don’t always take climate change into account. In this study, I4CE proposes immediate actions on three levers to initiate the process of adapting our buildings, and three more structural changes, including changes to thermal regulations.  

L’adaptation de la forêt française aux changements climatique devient un enjeu politique important. D’une part parce que, de sécheresses en incendies, les conséquences de l’évolution du climat sur les peuplements sont de plus en plus visibles. D’autres part parce que son adaptation est une condition indispensable pour que la forêt joue le rôle central que l’on attend d’elle dans l’atténuation du changement climatique.

In order to understand what public financial institutions can do, I4CE and Ramboll have analyzed 5 territorial projects, from the Vosges to the Dordogne, which are trying to meet the challenge of adaptation. Beyond their differences, each of the cases studied shows that adaptation requires, above all, dedicating time and resources to change the way projects are designed and carried out.

In this study, I4CE reviews the characteristics and areas of intervention of public financial institutions, which make them essential actors for adaptation. The study also reviews all of the Public Financial Institutions' business lines to determine their levers for action.

Increasingly frequent heat waves, long droughts, coastal erosion and changing flood risks are all impacts of climate change that will be problematic for the French economy and society. How detrimental this impact will be, will largely depend on what we have anticipated. If we organise ourselves well, we will be able to ensure we make the best decisions for a collective management of risks, development and economic choices, better suited to changing climates. However, regardless of whether we choose to reduce the exposure and vulnerability of populations, facilities and activities upstream or accept an increased share of risk, we must be prepared. 

For local governments, it is when expenditures are debated that it is possible to question them and to channel them towards the climate transition. That’s why I4CE and its partners co-constructed a common and shared methodology to assess a local budget according climate issues.

While France must adapt to the unavoidable consequences of climate disruption, it is necessary to monitor the financial resources that the State devotes to it. However, as the Senate's Foresight Delegation pointed out in 2019, the issue of financing adaptation is characterised by a lack of clarity on the level of needs and the amounts allocated.

It is no easy task to take climate risks – transition risks and physical risks – into account in financial management practices. As this note shows from the example of banking activities, the intrinsic characteristics of these risks – which are long-term and cannot be assigned a probability and for which there are no historical […]