Le plan de génie pour adapter la France au changement climatique

Climate inaction would cost 10,000 billion euros. Summer showed that France was unprepared for extreme events: deadly heatwaves, historic droughts, unprecedented megafires.

Can we adapt to the future to prevent these events? Adapting to 4 degrees in France is an illusion and amounts to discussing what we abandon, sacrifice, protect, and preserve.

Ilian Mib, climate resilience expert, responds to the main solutions proposed by policymakers to adapt France to tomorrow's climate.

• The climate debate and protecting cities during heatwaves • Saving agriculture from droughts • Feeding ourselves in tomorrow's climate • An overlooked player: insurers

Air conditioning appeals to media because it transforms a systemic issue into a for/against debate. According to the guest, it is very limited compared to the systemic scope of climate change impacts.

• We must air-condition public spaces, with a refuge within 10 minutes of everyone • In 2026, Paris's air-conditioned municipal spaces were open during the day when health impacts concentrated at night • We need nighttime refuge spaces, such as shopping centers requisitioned at night

• It cools indoors while dumping heat outside, a form of coolness privatization • It increases urban heat island effect, creating a self-reinforcing cycle • It has limits: in 2026, La Défense's air conditioning failed due to temperature

• De-seal cities with green and blue corridors, parks, urban forests and gardens to promote evapotranspiration • Comprehensive thermal renovation including heat: solar protection, passive nighttime ventilation, vegetated facades, high-albedo coatings • 12 million people face energy poverty • Guillaume Faburel suggests cities may need to shrink, a debate to be held

Gabriel Attal wants to remove all barriers to water storage projects, especially mega-reservoirs, to help farmers struggling with water access.

• Proposals concern mega-reservoirs for certain farmers, not public ones managed by water agencies • They would mainly benefit corn producers close to FNSEA and Coordination rurale • This leads to privatization of water resources

• Farmers already use 50% of water, while 86% of water management funding comes from households • Mega-reservoirs accelerate the water cycle, causing drier soils and more impactful rainfall • We must slow it instead

Regenerative hydrology (terraced farming, swales, keyline design, crop diversity) slows, distributes, infiltrates and stores rainwater in soils for more resilient agriculture.

Maximizing output with minimal input means uniformity, relying on fertilizers and pesticides, and hierarchical organization with free trade. Each optimization creates fragilities.

In unstable climate, each fragility becomes a potential rupture, as in summer 2026. Current response is hoarding during scarcity, including at geopolitical scale with Trump.

It means ensuring stability despite external fluctuations through diversifying crops and redundancy in agricultural models and distribution channels.

Choose resilience over performance by centering production on needs.

Responding to a statement blaming fires on arsonists and lost youth, the guest counters that 1% of fires cause 50% of damage and we cannot prevent all fire starts.

• 9 of 10 forest fires are human-caused, but fire management worked until early 2020s • Forests, three-quarters private, are organized to produce more wood with uniform plantations and accelerated rotations • Landes megafires stem from massive maritime pine plantations

• Mix ages and species with aging islands • Rehydrate forests, especially by restoring wetlands in the Landes • Test new species for diversification

• A mature 40-year-old tree transpires about 100 liters of water daily in cities • Agroforestry lets trees draw deep water for farm plots • Adaptation won't suffice: new megafires will occur

Christophe Cassou recalls that adapting to +4 degrees means choosing between sacrifice and protection. Disaster victims struggle with insurance contract complexity, as Sébastien Lecornu noted.

• Henry de Castries, Axa CEO in 2015, said a world 4 degrees warmer would be uninsurable • More municipalities lack insurers, as in the Roya valley • Insurers flee uninsurable territories or raise premiums

According to Reclaim Finance, natural disaster costs rise but major insurers' dividends also rise, up 20%.

• Create a National Climate Insurance Fund, financed by property levy, insurer windfall profits and state contribution • It would fund prevention and compensation, including city de-sealing and forest and stream restoration • Otherwise, insurer nationalization may be necessary

According to the guest, the most systemic measure is organizing planning around ecoregions—the six major watersheds with similar hydrological characteristics.

Inspired by economist Otto Neurath, the idea is directing production to local needs: establish territory needs profile, compare to production, plan the gap.

• Rely on water agencies, one per watershed, and their water parliaments • Add ecological accounting measuring activity impact against planetary boundaries • Create a sort of INSEE for the doughnut measuring vital needs and ecological impact

Perform constrained planning by developing necessary production capacity while limiting ecosystem impact.

Choose resilience over performance: diversify, restore ecosystems, use nature's services and revise territorial planning and decision-making.

Christophe Béchu speaks of a project comparable to post-war reconstruction. Adapting cities, agriculture, forests, housing and insurance systems requires investment, planning and political will.

Doing nothing costs far more: €1 invested in adaptation saves €7 in the future.

• Ilian Mundim's book on ecological social securities • Adaptation does not replace emissions mitigation • 2027 presidential election and call to support Limite, independent media, via Tipeee