Cities and coastlines facing climate vulnerabilities: anticipate to better adapt
The French territories, and in particular the Mediterranean and Atlantic coastlines, are on the front line facing the impacts of climate change. Coastal erosion, marine submersions, droughts, and heat waves: all phenomena that directly threaten populations, infrastructures, and ecosystems. The recent report by the Cour des comptes on the Mediterranean highlights the scale of the issues: 1.4 million housing units threatened in France by 2100, including 55,000 inthe Mediterranean, an estimated cost of inaction of over 54 billion euros by 2055, and still fragmented public policies.
Climate Vulnerability: Understanding Risks to Act Better
The concept of territorial vulnerability is based on the combination of three key dimensions:
Exposure (for example, the location of a site in a submersible or erodible area).
Sensitivity (socio-economic characteristics, type of buildings, current activities).
Adaptive capacity (financial resources, local policies, available innovations).
A territory can thus be vulnerable even without being directly exposed if it lacks the means to respond effectively. Conversely, an exposed territory that is well-prepared can significantly reduce its impacts. The TACCT tool, supported by ADEME, offers a comprehensive approach to diagnose these vulnerabilities, prioritize issues, and co-construct adaptation pathways.
Mediterranean Coast: Between Attractiveness and Fragility
With its 1,700 km of coastline and a rapidly growing population (+13% by 2050), the Mediterranean illustrates the current contradictions: a very attractive space, but already significantly weakened by coastal retreat, urban pressure, and the increasing risks of climate change. Cerema estimates that nearly half of the threatened housing units are located in Occitanie, a particularly vulnerable region.
Recent storms (Ciaran, Domingos, Géraldine in 2023) have highlighted the extent of the damage: over 500,000 claims and 1.3 billion euros in damages. Among the most affected sites are the campsites and tourist infrastructures located closest to the shore.
Public policies still insufficient
While prevention plans have existed since the Xynthia storm (2010), the Court of Auditors criticizes incomplete, poorly coordinated measures that too often depend on the willingness of municipalities. However, the inter-municipal or regional level is crucial for organizing a coherent response and avoiding contradictory decisions.
Seven priority recommendations emerge: better information for buyers, mapping of financial vulnerabilities, mandatory transfer of urban planning to inter-municipalities, local integrated coastal management strategies, partnership development projects, optimization of the GEMAPI tax, and creation of dedicated land establishments.
The central role of digital technology in adaptation
In the age of big data, solutions like ThinkCities® provide concrete tools for translating climate complexity into operational decisions. These platforms allow for:
Dynamic mapping of risks (erosion, flooding, heat waves, water stress).
Forward-looking simulation, by modeling different scenarios: centennial coastline, +20 cm, +60 cm, etc.
Economic and environmental evaluation of adaptation strategies (relocation, elevation, nature-based solutions).
Real-time monitoring thanks to data from sensors (water, air, temperatures).
Examples of Concrete Application
UrbanThink has already supported several stakeholders:
Camping de Kerpenhir (Morbihan): diagnosis of coastal risks and adaptation plan to secure infrastructure.
Domaine des Ormes : monitoring and reduction of energy consumption in the outdoor hospitality sector.
These projects illustrate how a territorial digital twin can transform the approach to vulnerability into a lever for sustainable transition and informed governance.
Conclusion: Act Now
Climate vulnerability is not an inevitability. It can be anticipated, measured, and reduced through appropriate strategies and effective digital tools. The report from the Court of Accounts is unequivocal: inaction will cost more than adaptation. Territories must therefore commit to resilience trajectories, integrating digital and collective intelligence at the heart of their planning policies from today.
In summary, thinking about the coast and the cities of tomorrow means today combining anticipation, innovation, and territorial solidarity.
