Indicator Climate

Forest land dominates the greenhouse gas balance of Switzerland’s land use. With the exception of a single year (2000), forest management has always resulted in a distinct increase in the total carbon reservoir in trees, dead wood, litter and forest soils (so-called forest sink). The forced usage following severe storms (Vivian in February 1990, Lothar in December 1999) and the rise in volumes harvested in some years (e.g. 2006 and 2007) are clearly recognisable. The data from the National Forest Inventory show that, since the 1990s, Swiss forests have tended to absorb and store less CO₂ per year. It is unclear how strongly the accumulation of hot and dry summers in the past decade, which caused drastic forest damage in many European countries, affects Switzerland. In view of the climate changes already observed and emerging, sensitive forest stands must be adapted to future site conditions by means of adaptive, close-to-nature silviculture. The measures required for this are likely to reduce the sink performance of the forest temporarily, but in the long term they will reduce the risk of large-scale damage due to natural disturbances.

In terms of climate policy, sound forest management can be achieved by using the wood grown in a cascade, firstly for long-lasting, high-quality harvested wood products and subsequently as fuel. In almost all the years since 1990, more wood has been incorporated into new products (such as building timber or furniture) than has been released again (as CO₂) during the disposal and/or incineration of disused wood products. However, the annual sink from harvested wood products has tended to decrease in recent decades.

The agricultural use of cropland and grassland affects the carbon stock of the soil. For example, ploughing encourages the depletion of humus, whereas spreading farmyard manure or leaving harvest residues on the fields increases their carbon stock. In addition to the farming method, the main factors influencing the annual fluctuations are the crops grown and, above all, the weather conditions. The case of drained former peatlands is a special one. When subjected to intense agricultural use, these fertile soils release large amounts of the greenhouse gases CO₂ and N₂O.

Wetlands now only account for a small part of the land area. As almost all of the remaining peatlands have been impaired by the consequences of previous use (particularly drainage), the build-up of peat has stopped, and many of the former sinks are now sources of greenhouse gases.

The development of new settlements has resulted in comparatively low emissions since 1990. Emissions are mainly produced if trees have to be felled during construction work. By contrast, the increasing greening of sealed surfaces in recent decades has helped to contain net emissions in urban areas.

Other land such as rocks, scree and glacier forelands have very little vegetation and only poorly developed soil or none at all. These areas play an insignificant role in the greenhouse gas balance.

With the exception of the years 2000, 2015, 2018 and 2023 Switzerland’s land use resulted in more CO₂ being absorbed from the atmosphere by the vegetation and soils than was emitted. Switzerland's annual net greenhouse gas emissions decreased as a result of this ecosystem service. In particular, the unsustainable use of former peatland and the consumption of land for housing and transport continue to release greenhouse gases. Therefore, the situation is not fully satisfactory. Many factors, such as forestry and agricultural policy, spatial planning, construction activity and extreme weather events, influence the greenhouse gas balance of the land use sector. No criteria have yet been defined for evaluating the development of the indicator.

• Related indicators
• Greenhouse gas emissions
• Treibhausgasemissionen nach Gasen
• Treibhausgasemissionen nach Sektoren

The greenhouse gas balance of land use can be compared to the data from other countries, given that it is calculated in accordance with the IPCC guidelines.

The data are taken from the inventory of greenhouse gas emissions in Switzerland (Land Use, Land-Use Change and Forestry Sector), which is drawn up annually by the FOEN in accordance with the guidelines of the UN Framework Convention on Climate Change. The methods are consistent with the guidelines of the IPCC (Intergovernmental Panel on Climate Change).

The greenhouse gas fluxes are surveyed for six categories of land use: forest land, cropland, grassland, wetlands, settlements and other land. The carbon stock of harvested wood products made from Swiss wood is also recorded. CO₂ is the most important greenhouse gas by far in the Land Use sector. Methane (CH₄) and nitrous oxide (N₂O) from fires, humus depletion, reservoirs and drained peatlands make a minor contribution to the emissions. The emissions of CH₄ and N₂O are converted to CO₂ equivalents and added to the CO₂ emissions.