The Land Use sector records greenhouse gas fluxes that occur in connection with land use (such as forestry and agriculture, settlements or protection areas) or as the result of a change in land use, such as building houses on former cropland. Unlike the other sectors, which only produce emissions, the carbon stock of the soil and vegetation can increase and thus remove carbon dioxide (CO2) from the atmosphere (so-called carbon sinks).
The greenhouse gas fluxes are surveyed for six categories of land use: forest, cropland, grassland, wetlands, settlements and unproductive land (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. With the exception of 2000, Switzerland’s land use resulted in more CO2 equivalents being absorbed from the atmosphere by the soil and vegetation than were emitted. Switzerland thus reduced its annual net emissions of greenhouse gases.
Forest dominates the greenhouse gas balance of Switzerland’s land use. Most years, forest management has resulted in a distinct increase in the total carbon reservoir in trees, dead wood, litter and forest soils (“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, 2007, 2014) are clearly recognisable. 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 from old ones. The size of the annual sink from harvested wood products has fallen in the past few years.
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. As well as the farming method, the main factors influencing the annual fluctuations are the crops grown and the climatic 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.
Unproductive land such as rocks, scree and glacier forelands have very little vegetation and only poorly developed soil or none at all. These areas therefore play an insignificant role in the greenhouse gas balance.
According to the convention, the land use sector is not included in the greenhouse gas inventory total. The greenhouse gas balance for land use may be included in order to monitor target achievement, but with clearly defined rules. Details on the inclusion of the greenhouse gas balance for land use are available under the following link:
Emissionsübersicht: Tabellen zum Bericht (Version Juli 2023) (XLSX, 350 kB, 11.07.2023)Tabellen zum Bericht «Emissionen von Treibhausgasen nach CO2-Gesetz und Übereinkommen von Paris» (in German, also available in French)
Last modification 11.04.2023