Health, Policy and You: How Zurich Responds

Heat: the deadliest climate hazard in Switzerland

Summer (May–Sep)	Heat-related deaths in Switzerland
2003	1,402
2015	747
2018	391
2022	474
2023	556
2024	326 (85% aged 75+)

Source: Swiss TPH monitoring for FOEN/FOPH (2025). Heat is the natural hazard that kills the most people in Switzerland.

• A University of Bern study counted 623 heat deaths in June–August 2022 and attributes about 60% of them — more than 370 people — to climate change. Zurich was among the hardest-hit urban cantons.
• Summer 2022 was hotter than 2015, yet fewer people died, and deaths per head are not rising in line with summer temperatures. Researchers credit better adaptation: warnings, awareness and care for the elderly. Cantons with heat action plans (Ticino, French-speaking Switzerland) saw the strongest declines after 2003.
• Most at risk: older people, people with chronic illness, pregnant women and small children. In Zurich, seniors can get free home visits during heatwaves via the 24/7 medical line AERZTEFON (0800 33 66 55).
• MeteoSwiss issues heat warnings (levels 2–4) based on the 24-hour mean temperature, so hot nights count, not just hot afternoons.

Pollen and allergies

A Swiss TPH and MeteoSwiss study of 30 years of data (1990–2020, all 14 Swiss pollen stations) found that at least four tree species now start their pollen season earlier — sometimes before January — and several seasons have become longer and more intense. About 20% of people in Switzerland have a pollen allergy, compared with under 1% a century ago.

New disease carriers

• Ticks: all of Switzerland except Ticino is now a risk area for tick-borne encephalitis (TBE/FSME). The Federal Office of Public Health names favourable climate conditions as a likely reason for rising cases and recommends vaccination for exposed people.
• Tiger mosquito: established in parts of Zurich since about 2023/24 (see Module 4). It can transmit dengue, chikungunya and Zika; no local transmission has occurred in Switzerland so far.

Air quality

Heat waves favour ground-level ozone. About 100,000 Zurich residents are exposed to elevated air pollution (fine particulates, NO₂, ozone), according to the city's Environmental Report 2025.

Mitigation means reducing greenhouse-gas emissions to limit future warming.

The targets

Level	Target	Basis
City of Zurich	Net zero direct emissions by 2040; indirect emissions −30% per person vs 1990	Popular vote, 15 May 2022 (75% yes)
City administration	Climate neutral by 2035	Same vote
Kanton Zürich	Net zero by 2040, at the latest 2050 (climate strategy 2022)	A law anchoring this was rejected on 28 Sep 2025 (59.5% no)
Switzerland	Net zero by 2050	Climate and Innovation Act, 18 Jun 2023 (59.1% yes), in force since 1 Jan 2025

Direct vs indirect emissions

Emissions per City of Zurich resident in 2024:

• Direct emissions (inside city borders, mainly heating and traffic): 2.2 t CO₂e
• Indirect emissions (consumption, food, flights, building materials — produced elsewhere): 11.9 t CO₂e
• Total: about 14 t CO₂e per person — roughly 85% indirect.

For comparison: the Swiss consumption footprint was about 13 t CO₂e per person in 2019, and about two-thirds of it arises abroad. A climate-compatible level is about 0.6 t per person.

Key levers

• Heating: about half of the city's direct CO₂ comes from heating. Around 21,000 fossil heating systems need replacing.
• District heating: in June 2026, voters approved a CHF 2.26 billion credit (80.7% yes) to connect 60% of the settlement area by 2040, roughly doubling the network.

Adaptation means preparing for the climate change we can no longer avoid.

• Fachplanung Hitzeminderung (2020): the city's heat-reduction plan protects cold-air corridors and guides measures such as trees, shade, unsealed surfaces and water features.
• Tree canopy: the Fachplanung Stadtbäume (2022) aims to raise canopy cover from about 17% (2018) to 25% by 2050. Canopy cover is currently about 15.4%, and the city itself says the target is uncertain because of densification and losses on private land.
• Sponge city (Schwammstadt): instead of piping rain away, the city stores it where it falls — in permeable soil, trees and green roofs. One square metre of permeable soil absorbs about 500 L of rain per year; green roofs can retain up to 70% of rainfall; a large street tree cools its surroundings by 4–7 °C. Examples: Greencity, Hunzikerareal (Oerlikon).
• Legal change: since 1 December 2024, the cantonal planning and building law (PBG §238a) requires greening and minimal sealing, and municipalities can set binding heat-reduction rules.
• Climate maps: the canton publishes climate maps at 5 × 5 m resolution, including a +2.5 °C scenario, to guide planners.

Your university

• UZH: aims for climate-neutral operations by 2030. The share of meat meals in UZH canteens fell from 69% (2017) to 36% (2022).
• ETH Zurich: the ETH Netto-Null programme aims to cut emissions significantly by 2030. Business travel is about 7% of ETH's emissions — over 95% of it flights.
• Get involved: UZH lists 17 student-led sustainability initiatives, including Sustainability Week Zurich, which grew into Sustainability Week Switzerland.

Your biggest personal levers

The largest parts of a Swiss footprint are housing, food and mobility. Flights alone are roughly one fifth of the Swiss greenhouse-gas footprint (approximate).

Lever	Why it matters
Fly less, take the train	A long-haul return flight emits on the order of 1–3 t CO₂e per passenger (approximate) — comparable to a Zurich resident's 2.2 t of direct emissions per year
Eat more plant-based	Food is one of the three biggest footprint areas
Choose renewable heating & electricity (as tenant: ask!)	Heating is about half of Zurich's direct emissions
Vote and engage	Zurich's targets were set by popular vote