Switzerland’s emissions gap is larger than officially stated

Traffic around Zurich. Keystone / Gaetan Bally

Switzerland’s climate emissions gap is significantly larger than officially reported, according to research by the Swiss public broadcaster SRF, which shows the environment office underestimated the shortfall by up to a third.

34 million tonnes of CO₂: this is the amount Switzerland is expected to be unable to reduce domestically by 2030 and will instead have to offset abroad. The Federal Council communicated this figure to parliament last year. But research by SRF shows that the gap is significantly larger. The Federal Office for the Environment (FOEN) underestimated it by up to one third – despite being aware of the higher figure.

The issue was first raised by Centre Party politician Christine Bulliard-Marbach in a written interpellationExternal link to the government. Her questions focused on Switzerland’s approach to CO₂ compensation: emissions that cannot be avoided domestically are to be offset through climate projects abroad. The larger the emissions gap, the higher the costs for the federal budget – and ultimately for taxpayers. At the same time, the figure reflects Switzerland’s progress in climate protection. A sound calculation of this gap is therefore crucial.

FOEN calculation excludes forest and land use

However, this calculation is now under scrutiny. The actual emissions gap is likely to be significantly larger than the Federal Council has reported. An earlier SRF forecastExternal link had already raised doubts. Now, via the Freedom of Information Act, SRF has obtained access to the FOEN’s internal calculation on which the official emissions gap figure is based. This reveals that the methodology did not comply with the rules of the Paris Agreement.

A key component was omitted: the land-use sector – known as “land use, land-use change, and forestry” (LULUCF).External link This includes emissions absorbed or released by forests and soils in Switzerland.

Excluding this sector leads to a substantial underestimation. Depending on the scenario, the gap by 2030 is underestimated by approximately 7 to 18 million tonnes of CO₂. This corresponds to additional, previously undisclosed costs of CHF245 million ($307 million) to CHF630 million.

Taking this into account, Switzerland’s realistic emissions gap by 2030 would be between 40 and 50 million tonnes of CO₂ – up to 50% higher than officially stated. Total costs for Swiss taxpayers could rise to as much as CHF1 billion by 2030. Moreover, the FOEN methodology made Switzerland’s climate progress appear significantly more favourable than it actually is.

The effect of land use

Switzerland’s climate target – a reduction in greenhouse gas emissions of at least 35% between 2021 and 2030 compared to 1990—is based on net emissions, meaning all sources and sinks are included.

A key factor is land use or “land use, land-use change, and forestry” (LULUCF), which refers to the contributions of Switzerland’s forests and soils, which store large quantities of carbon. Switzerland’s forests and soils historically functioned as a carbon sink, absorbing more CO₂ than they emitted. However, since 1990, this sink has steadily weakened due to factors such as heat and drought. In recent years (2018, 2022, 2023, and 2024), the land-use sector has even turned into a net source of CO₂, meaning it emits more greenhouse gases than it can absorb.

Because the carbon sink has diminished significantly since the reference year 1990, reductions in gross emissions (excluding land use) appear larger than reductions in net emissions. Calculations based solely on gross emissions therefore result in a smaller calculated target gap than when using net emissions, which are decisive for achieving the target.

Several experts have confirmed this. Cyril Brunner, a climate physicist at the federal technology institute ETH Zurich, has independently analysed SRF’s scenarios and reached similar conclusions.

Environment office defends its approach

When asked, the FOEN acknowledged that its calculation is not aligned with current Swiss climate targets. It stated that the figure was based on Swiss law as it stood at the time – not on the Paris Agreement rules. The inclusion of the land-use sector only became legally relevant three-and-a-half months after the parliamentary interpellation was answered. The FOEN also noted that it had communicated the issue earlier as part of its annual greenhouse gas inventory.

Trees that died due to drought in the Jura Mountains. Swiss forests can also become a source of CO2 emissions. Keystone / Jean-Christophe Bott

However, the new CO₂ Act, which entered into force at the beginning of 2025, was always intended to align Swiss law with the Paris Agreement. In its messageExternal link accompanying the draft law from 2022, the Federal Council wrote: “The reduction targets to which Switzerland committed itself under the Paris Agreement will be incorporated into the CO₂ law” and “the scope of the law should […] encompass the effects of forests, timber used in construction, and land use”.

The later amendment to the ordinance therefore does not represent a sudden change in the basis of calculation, but merely a formal clarification of the existing legal interpretation.

Critics demand greater transparency

Axel Michaelowa, a climate researcher at the University of Zurich, believes the FOEN should have clearly communicated any changes to its calculation methods. “We have three-and-a-half years until 2030; political action is needed now,” he said.

Christine Bulliard-Marbach, the parliamentarian who initiated the inquiry, feels she has not been properly informed by the environment office: “These figures are a crucial basis for decision-making in parliament. Clear communication would have been better.”

Patrick Hofstetter, a climate expert at WWF Switzerland, says the revised figures change the situation. He calls on the Federal Council to make greater use of its powers – for example by requiring fuel importers to offset a larger share of emissions. He also urges a transparent strategy for financing the additional costs.

According to Hofstetter, the case shows “once again how far Switzerland is from taking a leading role in climate protection, despite favourable conditions”.

The FOEN says that the Federal Council plans to hold a discussion in 2027 to assess progress towards the 2030 targets and to specify the costs of closing the gap in greater detail. Land use will be included in this assessment.

SRF’s forecast

The contribution of the land-use sector varies considerably from year to year and is subject to significant uncertainty. However, the long-term trend is clear: the carbon sink has weakened since 1990 due to climate change and has recently become a net source of emissions (2018, 2022, 2023 and 2024).

To assess how including the land-use sector would have affected the FOEN’s calculations, two scenarios were considered for the years 2023–2030, based on the 2024 greenhouse gas inventory used at that time.

One scenario was more optimistic, in which the land-use sector stabilised at the level of the previous years (2013–2020), and the other was more pessimistic, in which the land-use sector continued to develop on average as it had (trend fit over the years 1990–2022). These two scenarios resulted in a target gap that was 7 to 18 million tonnes of CO₂ larger than originally calculated by the FOEN (41.5–50.1 million tonnes of CO₂). At a price of CHF35 per tonne of CO₂, this corresponds to additional CHF 245–630 million in previously undisclosed costs. However, depending on the actual development of the land sector’s greenhouse gas balance, this deviation may be larger or smaller.

Repeating the calculation with the data available today, based on the 2026 greenhouse gas inventory, yields a slightly smaller gap of 40.8–50.1 million tonnes of CO₂.

Translated from German via AI/sb/ts