- Switzerland 2026
- Chapter 1
Switzerland’s risk starts in the mountains and runs through water
Part I describes systems and their couplings. It assesses no authority and ranks no canton.
Contents
- ·Edition home
- ·Executive summary
- 1Switzerland’s risk starts in the mountains and runs through water
- 2Key findings
- 3Systems and sectors at baseline
- 4Risks and capability
- 5Dry year with low reservoirs and low river flows
- 6Readings from the other desks
- 7The 2027 agenda
- 8Systems in depth
- AMethodology
- BData appendix
- CReferences and record
- ·Complete edition, for print
1.1The questions this part answers
Key questions
- Where is Switzerland’s risk concentrated, and in which systems?
- Which couplings carry shocks from one system to the next?
- Which capabilities hold under compound stress, and which are only documented?
- What must the 2027 programme measure first?
In this part
- Narrative
- Headline finding
- Lead figure
- Five system chapters
- Twelve-domain reading
- Sector screens
- Dependency matrix
- Risk objects
- Capability ladder
- Scenario
- Three lenses
- Portfolio
1.2The argument
Switzerland is a small, wealthy, mountainous country with 9.13 million residents1. Its systems are tied to snow, ice and the rivers that leave the Alps. This baseline reads its exposure as three forces acting together: warming that is faster than the global average, an electricity system built on Alpine hydropower and imports, and settlements built below unstable slopes.
Warming is the first force. The current climate mean is 2.8 °C above the pre-industrial average4, and 2025 was the fourth-warmest year since records began in 186412. Glaciers lost almost 3% of their volume in 2025 and about a quarter since 201513. On 28 May 2025 a small glacier at Blatten collapsed under the weight of rock that had fallen onto it, and the collapse buried most of the village1415. Insured damage was put at CHF 255 million16.
The water layer showed its other face in 2026. A snow-poor winter and a dry spring left the Rhine, the Aare and Lake Constance at record lows in June21. Between April and July about one-fifth of monitoring stations recorded their lowest level for the period19, the Rhine at Basel flowed less in July than in summer 2003, and Lake Zurich reached its lowest level since 1951 on 19 August20. More than 80% of drinking water comes from larger underground sources, and the groundwater monitoring network is thin22.
The energy layer follows the water. Hydropower supplied 55.5% of domestic generation in 2025 and nuclear power 27.2%6. Hydropower output fell 22.5% from the record of 20246, and reservoirs stood at 46% full in mid-July 20268. All natural gas was imported in 2025, and biogas feed-in into the gas grid was 510 GWh6. Emissions were 40.1 MtCO₂e in 20243, and the second contribution sets a 2031–2035 budget of 106.8 MtCO₂e4.
The social layer sets how much shock the country can absorb. People aged 65 or over now outnumber those under 202. Heat caused an estimated 623 deaths in the summer of 2022, 542 in 2023 and 326 in 20241817. The IMF describes strong public finances and a debt brake it judges appropriate, and it expects spending pressure from pensions, health and the low-carbon transition2829.
This edition therefore reads Switzerland’s risk as a property of the couplings between these forces. The civil protection office’s national analysis already names a long power shortage and a pandemic among the largest national risks24. The matrix, risk objects, capability ladder and scenario that follow ask the same two questions: where does a shock travel next, and who holds the capability to stop it?
The inventory total was 40.1 MtCO₂e in 2024, with transport the largest source at 13.43. The 2031–2035 budget of 106.8 MtCO₂e averages 21.4 a year4. The two are not on a matched basis, and the share of reductions realised abroad is not disclosed5.
| Item | Bar, scaled to the largest value | Value |
|---|---|---|
| Total 2024 (excl. land use and international aviation) | 40 | |
| Transport 2024 | 13 | |
| Industry 2024 | 9 | |
| Buildings 2024 | 9 | |
| Agriculture 2024 | 7 | |
| Annual mean of the 2031–2035 budget | 21 |
Source: as cited in the note to this figure. Year 2024.
Figure ID FIG-COUNTRY-CHE-2026-BASELINE-01-003
1.3Twenty couplings between five systems
The Switzerland matrix types the twenty couplings between the five core systems. Strengths are Nexus estimates from the cited evidence and analogue events; they set the starting graph that the Q1 2027 Foundry cut will test.
Each line is one coupling from one system to another, drawn by the strength the edition assigns. Strengths are Nexus estimates from the cited evidence and analogue events.
- Strong
- Moderate
- Weak
Source: this edition’s coupling matrix (Table 1.1); status Estimated.
| From, to | WAT | ENE | FOO | HLT | BIO |
|---|---|---|---|---|---|
| WAT Water | · | STRONG hydropower · cooling | MODERATE irrigation · pasture | MODERATE drinking water | STRONG streams · lakes · groundwater |
| ENE Energy | MODERATE pumping · pumped storage | · | MODERATE fuel · heating · cold chain | STRONG facility power · cooling | MODERATE reservoirs · land use |
| FOO Food | MODERATE withdrawals · nutrients | WEAK biogas | · | MODERATE nutrition · food safety | STRONG land use · nitrogen |
| HLT Health | WEAK workforce | WEAK workforce | WEAK labour | · | WEAK residues |
| BIO Biodiversity | STRONG forest and wetland regulation | WEAK biomass | STRONG pollination · soils | WEAK zoonoses · air | · |
| Strength: strong, moderate or weak; a Nexus estimate (status Estimated) from cited evidence and analogue events. The scale is defined in Annex A. | |||||
Transmission paths
- 01
CLI → WAT → ENE
A snow-poor winter and dry spring lower rivers and reservoirs and cut hydropower.
- 02
CLI → WAT → FOO
Drought strains pastures and farm liquidity.
Reported 202633
- 03
CLI → INF
Glacier and rock failure above a village destroys homes and roads.
Reported Blatten 202514
- 04
CLI → HLT
Hot summers raise deaths among older people.
- 05
ENE → FIN
Low hydropower raises import needs and exposure to foreign supply.
Inferred not bound for Switzerland
1.4Reinforcing loops
A shock entering either system of a loop can return amplified through the other.
| Loop | First direction | Second direction |
|---|---|---|
| WAT and BIO | Water to biodiversity: streams · lakes · groundwater | Biodiversity to water: forest and wetland regulation |
| FOO and BIO | Food to biodiversity: land use · nitrogen | Biodiversity to food: pollination · soils |
| A causal-loop reading of the matrix (Sterman, Business Dynamics, 2000): structural, from estimated strengths, not a measured feedback. | ||
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
- 1Federal Council (ed.), “Population growth slowed slightly in 2025”, release on final STATPOP results of the Federal Statistical Office (permanent resident population 9,127,100 on 31 December 2025, up 0.8%). Swiss Confederation, Neuchâtel, 20 August 2026. Observation year 2025. https://www.admin.ch/en/newnsb/eHho7S2A2revQdhyPSYmt, accessed 2026-11-03.back
- 4Switzerland (ed.), Switzerland’s second nationally determined contribution under the Paris Agreement 2031–2035. Federal Office for the Environment for the UNFCCC, Bern, January 2025. Observation years 2022–2035. https://unfccc.int/sites/default/files/2025-01/Switzerland%20second%20NDC%202031-2035.pdf, accessed 2026-11-03.back
- 12MeteoSwiss (ed.), national temperature for 2025 (1.2 °C above the 1991–2020 norm; fourth-warmest year since 1864), as reported by Keystone-SDA on swissinfo.ch, 19 December 2025. MeteoSwiss, Zurich, 2025. Observation year 2025. https://www.swissinfo.ch/eng/climate-adaptation/2025-is-the-fourth-warmest-year-in-switzerland-since-measurements-began/90668352, accessed 2026-11-03. Press report; the final annual bulletin was not rendered.back
- 13ETH Zurich (ed.), Swiss glaciers lost almost 3% of their volume in 2025 and about a quarter since 2015 (GLAMOS monitoring, Swiss Commission for Cryosphere Observation), as published by ScienceDaily, 2 October 2025. ETH Zurich, 2025. Observation year 2025. https://www.sciencedaily.com/releases/2025/10/251001092211.htm, accessed 2026-11-03.back
- 14D. Farinotti, M. Huss, M. Jacquemart and M. Werder (eds.), Fact sheet for the now-collapsed Birchgletscher, Switzerland, document 88028-VAW-2025-06. VAW, ETH Zurich, Zurich, 2 June 2025. Observation year 2025. https://raonline.ch/pages/edu/pdfNW/VAW_BirchgletscherFS2025.pdf, accessed 2026-11-03.back
- 15Wikipedia contributors, 2025 Blatten glacier collapse (28 May 2025; evacuations from 17 and 19 May; one death outside the evacuation zone). Wikimedia Foundation, 2025–2026. Observation year 2025. https://en.wikipedia.org/wiki/2025_Blatten_glacier_collapse, accessed 2026-11-03. Reference compilation, not a primary source; used for the casualty and evacuation facts only.back
- 16Insurers’ natural hazard pool (ed.), annual financial statements: Blatten landslide, total insured damage CHF 255 million (CHF 240 million within the pool; more than 80% of insured sums for total losses paid after four months), as reported by swissinfo.ch, 26 May 2026. Observation year 2025. https://www.swissinfo.ch/eng/various/blatten-landslide-caused-damage-totalling-255-million-francs/91473640, accessed 2026-11-03. Press report of pool statements.back
- 21WSL Institute for Snow and Avalanche Research SLF (ed.), “The heat is gone, but the drought remains” (interview with M. Brunner; Rhine, Aare and Lake Constance at record lows; snowpack at most half the long-term average in the Dischma Valley). SLF, Davos, 12 June 2026. Observation year 2026. https://www.slf.ch/en/news/the-heat-is-gone-but-the-drought-remains/, accessed 2026-11-03.back
- 19FOEN (ed.), statement to Keystone-SDA on drought: historic lows at eleven stations in July 2026; about one-fifth of stations at a record low for the period from 1 April to 31 July. Published by blue News, 13 August 2026. Observation year 2026. https://www.bluewin.ch/en/news/drought-causes-swiss-water-levels-to-drop-to-record-lows-li.3561545, accessed 2026-11-03. Press report of a federal statement.back
- 20L. Jorio (ed.), “Drought in Switzerland: Europe’s water tower runs dry” (Lake Zurich lowest since records began in 1951 on 19 August 2026; Lake Constance 394.97 m on 11 August, 27 cm below the previous 1991–2020 low; Rhine at Basel in July below summer 2003). swissinfo.ch, 21 August 2026. Observation year 2026. https://www.swissinfo.ch/eng/climate-adaptation/drought-in-switzerland-europes-water-tower-runs-dry/91913797, accessed 2026-11-03. Press report; FOEN is the cited data source.back
- 22K. F. Brandt and S. Pasino (eds.), “How much water is left under Switzerland? Nobody can say yet” (more than 80% of drinking water from larger underground sources; 42 monitored springs; whole country at the highest drought danger level on 6 August 2026). swissinfo.ch, 24 August 2026. Observation year 2026. https://www.swissinfo.ch/eng/climate-solutions/how-much-water-is-left-under-switzerland-nobody-can-say-yet/91915172, accessed 2026-11-03. Press report; the federal environment office is the cited source.back
- 6Swiss Federal Office of Energy (SFOE) (ed.), Energy Consumption in Switzerland 2025, extract from the Swiss Overall Energy Statistics 2025 (ENSTAT). SFOE, Bern, June 2026. Observation year 2025. https://pubdb.bfe.admin.ch/en/publication/download/12648, accessed 2026-11-03.back
- 8SRF and swissinfo.ch (eds.), “Swiss reservoir water levels lowest in 20 years” (46% full, 16.4 points below the 20-year average, per the SFOE weekly report; reservoirs cover about 20% of winter-half demand). swissinfo.ch, 17 July 2026. Observation year 2026. https://www.swissinfo.ch/eng/climate-adaptation/swiss-reservoir-water-levels-lowest-in-20-years/91760665, accessed 2026-11-03. Press report of SFOE figures.back
- 3Federal Office for the Environment (FOEN) (ed.), “Inventaire des gaz à effet de serre pour l’année 2024: légère baisse des émissions” (40.1 MtCO₂e, 27.3% below 1990; buildings 8.8, industry 8.9, transport 13.4 MtCO₂e; international aviation and maritime 5.5 MtCO₂e). Swiss Confederation, Bern, 13 April 2026. Observation year 2024. https://www.admin.ch/fr/newnsb/0x0fdVaborNCilTCosvky, accessed 2026-11-03.back
- 2Federal Statistical Office (ed.), provisional population results 2025 (permanent resident population 9,124,300; 1,811,000 aged 65 or over and 1,802,000 under 20), as reported by Keystone-SDA on swissinfo.ch, 2 April 2026. FSO, Neuchâtel, 2026. Observation year 2025. https://swissinfo.ch/eng/demographics/population-the-proportion-of-seniors-exceeds-that-of-young-people-in-switzerland/91200057, accessed 2026-11-03. Press report of the release; provisional figures.back
- 18A. M. Vicedo-Cabrera, E. de Schrijver, D. L. Schumacher, M. S. Ragettli, E. M. Fischer and S. I. Seneviratne, heat-related mortality in Switzerland, summer 2022 (623 deaths, 3.5% of deaths; about 60% attributable to human-induced warming), Environmental Research Letters, 2023, as summarised in a University of Bern release, 4 July 2023. Observation year 2022. https://mediarelations.unibe.ch/media_releases/2023/media_releases_2023/global_warming_caused_60_percent_of_swiss_heat_deaths_in_the_summer_of_2022/index_eng.html, accessed 2026-11-03.back
- 17Swiss TPH (ed.), HiMOMO: Monitoring heat-related deaths (542 deaths May to September 2023, 95% interval 364 to 715; 326 deaths May to September 2024, 95% interval 171 to 471). Swiss Tropical and Public Health Institute, Allschwil, for the Federal Office for the Environment, 2023–2026. Observation years 2023–2024. https://www.swisstph.ch/en/projects/project-detail/project/monitoring-heat-related-deaths, accessed 2026-11-03.back
- 28International Monetary Fund (ed.), Press Release No. 26/281: IMF Executive Board concludes 2026 Article IV consultation with Switzerland (2025 growth 1.4% unadjusted; inflation 0.2%; current account 6.4% of GDP). IMF, Washington, DC, 1 September 2026. Observation year 2025. https://www.imf.org/en/news/articles/2026/09/01/pr26281-switzerland-imf-executive-board-concludes-2026-article-iv-consultation, accessed 2026-11-03.back
- 29Federal Council (ed.), “International Monetary Fund praises the resilience of the Swiss economy” (debt brake appropriate; spending pressure from pensions, health and the low-carbon transition). Swiss Confederation, Bern, 25 June 2026. Observation year 2026. https://www.admin.ch/en/newnsb/9CnjDEMpjWvY_tyiCF7az, accessed 2026-11-03.back
- 24Federal Office for Civil Protection (BABS) (ed.), Katastrophen und Notlagen Schweiz 2025: Bericht zur nationalen Risikoanalyse (KNS 2025; 44 hazard dossiers; pandemic and prolonged power shortage the largest risks). BABS, Bern, February 2026. Observation year 2025. https://www.babs.admin.ch/dam/de/sd-web/PpZZg4eroKXo/KNS-2025-Risikobericht-final_de.pdf, accessed 2026-11-03. Report read in part (summary and results chapter).back
- 5Climate Action Tracker (ed.), Switzerland: 2035 NDC assessment (rating insufficient; share of the target met abroad not disclosed; submission on 29 January 2025). Climate Analytics and NewClimate Institute, February 2025. Observation year 2025. https://climateactiontracker.org/countries/switzerland/2035-ndc/, accessed 2026-11-03.back
- 33Federal Council (ed.), drought and heat aid package (CHF 54 million in interest-free operating loans for farm businesses in 2026; CHF 17.5 million more for forests in 2027), as reported by Keystone-SDA on blue News, 26 August 2026. Observation year 2026. https://www.bluewin.ch/en/news/federal-council-puts-together-a-multi-million-aid-package-to-combat-drought-and-heat-li.3576293, accessed 2026-11-03. Press report; Parliament decides on the funding.back