- France 2026
- Chapter 5
Hot, dry summer with low river flows
A conditional statement under stated assumptions, never a prediction.
Contents
- ·Edition home
- ·Executive summary
- 1France’s risk is coupled, not cumulative
- 2Key findings
- 3Systems and sectors at baseline
- 4Risks and capability
- 5Hot, dry summer with low river flows
- 6Lenses and readings
- 7The 2027 agenda
- 8Systems in depth
- AMethodology
- BData appendix
- CReferences and record
- ·Complete edition, for print
5.1Assumptions
Scenario SCN-FRA-HDN-01: what is assumed, and what is held constant.
- Baseline
- the 2026 reference state in this edition
- Drivers
- a dry winter and spring; repeated heatwaves above 40 °C in July and August; low flows on the Rhône, Loire and Garonne
- Analogues
- summers 200339, 2019 and 2022825
- Interventions
- none modelled, the specification describes the unmitigated case
- Run state
- narrative specification; quantified Foundry run scheduled for Q1 2027
5.2The cascade, step by step
- 1
CLI → WAT
low rainfall and heat cut river flows
2022
- 2
WAT → ENE
reactors cut output to respect discharge-temperature limits
202225
- 3
CLI → HLT
heat deaths among older people rise
2003 · 20244
- 4
WAT → FOO
irrigation restrictions and heat cut harvests
2022
- 5
CLI → BIO
wildfires in the south-west and beyond
202220
- 6
WAT → FIN
clay subsidence claims rise under CatNat
202213
5.3The scenario as a table of steps
How the shock in scenario SCN-FRA-HDN-01 would travel through France’s coupled systems, step by step, under the assumptions the edition states.
| Step | What happens | Source |
|---|---|---|
| 01 Climate to water | Low rainfall and heat cut river flows. Analogue or source: 2022. | Edition FRA, scenario SCN-FRA-HDN-01, step 1 |
| 02 Water to energy | Reactors cut output to respect discharge-temperature limits. Analogue or source: 2022 [25]. | Edition FRA, scenario SCN-FRA-HDN-01, step 2 |
| 03 Climate to health | Heat deaths among older people rise. Analogue or source: 2003 · 2024 [4]. | Edition FRA, scenario SCN-FRA-HDN-01, step 3 |
| 04 Water to food | Irrigation restrictions and heat cut harvests. Analogue or source: 2022. | Edition FRA, scenario SCN-FRA-HDN-01, step 4 |
| 05 Climate to biodiversity | Wildfires in the south-west and beyond. Analogue or source: 2022 [20]. | Edition FRA, scenario SCN-FRA-HDN-01, step 5 |
| 06 Water to finance | Clay subsidence claims rise under CatNat. Analogue or source: 2022 [13]. | Edition FRA, scenario SCN-FRA-HDN-01, step 6 |
A teaching model of a conditional scenario under the edition’s stated assumptions: not a forecast, not a prediction and not a warning. Sources: France 2026, scenario SCN-FRA-HDN-01 (2026); France 2026, references (NR-CIT-1) (2026).
Notes
Numbers are the edition’s reference numbers, so a note reads the same in every chapter. The full list, with every source and its licence, is in Annex C. Annex C, references
- 39J.-M. Robine, S. L. K. Cheung, S. Le Roy et al., “Death toll exceeded 70,000 in Europe during the summer of 2003,” Comptes Rendus Biologies, vol. 331, pp. 171–178, 2008.back
- 8Météo-France (ed.), Bilan climatique de l’année 2022 en France. Météo-France, Saint-Mandé, January 2023.back
- 25RTE (ed.), Bilan électrique 2022. RTE, Paris, February 2023.back
- 4Santé publique France (ed.), Chaleur et santé : bilan de l’été 2024. Santé publique France, Saint-Maurice, 2024.back
- 20J. San-Miguel-Ayanz et al. (eds.), Forest Fires in Europe, Middle East and North Africa 2022. Joint Research Centre, Ispra, 2023.back
- 13France Assureurs (ed.), Bilan des catastrophes naturelles et des événements climatiques 2022. France Assureurs, Paris, 2023.back