Adaptive Climate Policy Amid Uncertainty

As EU climate policy tightens, its Green Deal increasingly shapes Swiss energy and emissions through shared infrastructure – long-standing hydropower integration, electricity lines and gas pipelines –, Emissions Trading Systems (ETS) linkage and EU-wide clean fuel and CO₂ regulations. The conclusion of the researchers in the POLIZERO project, which set out to identify such robust pathways for Switzerland to reach net-zero in step with Europe, is clear:  Reaching net-zero isn’t about a perfect plan. It’s about policies and technology choices that remain effective, even when the future does not go as planned.

POLIZERO was funded by the Energy-Economy-Society research programme of the Swiss Federal Office of Energy. Led by the  Energy Economics Group of the Laboraotry for Energy Systems Analysis at the Paul Scherrer Institute PSI and the Technoeconomics of energy systems laboratory of the University of Piraeus Research Center, it combined stakeholder input, energy modelling (JRC-EU-TIMES, 2020–2050) and adaptive policy analysis (AIM) to explore resilient strategies across diverse futures – spanning technology costs, energy prices, economic trends, demographics and resource availability. The final report can be found here.

Why is 2025–2035 so critical for Switzerland’s energy transition?

POLIZERO shows this decade is key to replacing ageing heating, transport and industrial infrastructure with clean alternatives. Solar capacity must triple, energy use fall by 15%, and electric vehicles, heat pumps, and efficiency measures accelerate. District heating must expand to cover 10% of building heat demand (up from 7% today). These steps reduce import dependency and prepare for long-term decarbonisation.

What comes after 2035?

The focus shifts to scaling solutions. With nuclear phase-out and seasonal electricity needs, Switzerland will require 12 TWh of wind and bioenergy by 2050—half in winter. A third of district heating should come from large heat pumps. By 2050, about 25 TWh of synthetic fuels (biogenic or e-fuels) are needed for aviation, plus a smaller but strategic share of hydrogen (~6 TWh) for industry. CO2 capture of 6–10 Mt/year is needed, mainly from waste and industry. Delays in international fuel and CO2 transport agreements would require greater domestic carbon removal.

What kind of energy and climate policies were tested, and what worked best?

POLIZERO tested 12 policy packages based on subsidies, CO2 taxes, EU alignment (e.g. ETS, ETS2, vehicle standards), and mandates or bans (e.g., building codes). Stakeholder input informed the design of these packages. Harmonising with EU policies—or implementing Swiss equivalents—proved most robust, especially under uncertainty. Acting early boosts effectiveness. Stakeholders also recommended simplifying approval procedures for renewables and grids, reducing high upfront costs for technologies like heat pumps and tackling skilled labour shortages in construction, grid services and specialised clean-tech professions.

What does this mean for Swiss energy and climate policy?

Subsidies can kick-start decarbonisation but must be paired with mandates. CO? taxes work better in buildings than in transport, where vehicle standards are more effective. Skipping ETS2 means stronger taxes in both sectors, yet price signals alone don’t ensure results. Aligning with EU policies, or Swiss-tailored versions, offers greater certainty in cutting emissions, especially post-2035. In our modelling, this “quantity certainty” guarantees emission cuts regardless of price changes, while EU alignment adds benefits from cross-border market integration and coordinated infrastructure. Switzerland’s strategy must balance: 1) EU cooperation on clean fuel imports and CO2 transport, 2) timely, credible domestic action, and 3) close monitoring of policy shift risks and critical factors like bioenergy, synfuel imports and fuel prices.

Take-home message

POLIZERO does not offer a perfect blueprint—it identifies adaptive, scalable policies that stay effective as conditions evolve. For Switzerland, success means acting early and aligning with Europe—through smart regulation, infrastructure investment, and cross-border cooperation.

Authors:

Dr Evangelos Panos (PSI Centers for Nuclear Engineering and Sciences & Energy and Environmental Sciences – Laboratory for Energy Systems Analysis)
Dr. Serafeim Michas (University of Piraeus Research Center, Technoeconomics of Energy Systems laboratory)
Prof. Dr. Alexandros Flamos (University of Piraeus Research Center, Technoeconomics of Energy Systems laboratory)
MSc Meixi Zhang (PSI Centers for Nuclear Engineering and Sciences & Energy and Environmental Sciences – Laboratory for Energy Systems Analysis)
Prof. Dr. Russell McKenna (PSI Centers for Nuclear Engineering and Sciences & Energy and Environmental Sciences – Laboratory for Energy Systems Analysis , and Chair of Energy Systems Analysis ETH Zürich)

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