Carbon balance of land use
Soil use (e.g. forest management, agricultural land use) and land-use change (e.g. settlements built on former cropland) result either in the release or storage of greenhouse gases, which then reduces or increases the quantity of carbon stored in the soil and vegetation. Since the beginning of the commitment period under the Kyoto Protocol (2013-2020), carbon storage in wood products from Swiss timber sources has also been taken into account.
The Swiss forest has been a major carbon sink in most years since 1990. The decline from 2000 (and 2001) was due to storm "Lothar", which heavily damaged forests. Increased harvesting was also a factor in the years 1990 (storm "Vivian"), 2007 and 2014. Wood products, e.g. as construction timber or furniture, have also constituted a substantial carbon sink since 1990 (although its total volume has tended to decline in recent years).The soils are showing marked annual fluctuations between carbon release and capture which can be traced back to the cultivation of mineral soils under different climatic conditions. In contrast, the former wetlands that are drained and used for agriculture release greenhouse gases constantly. Finally, the development of new settlement and transport areas led to further greenhouse gas emissions in the period under review.
Forests (including wood products) compensate for the emissions caused by the use and change in use of other types of land-use categories, with the exception of the year 2000. In most years, significantly more CO2 equivalents were stored than released. Greenhouse gases continue to be released due mainly to the non-sustainable use of primary peaty soils and the use of land for settlement and traffic areas. For this reason, the state is not unreservedly satisfactory. The changes are impossible to evaluate since many factors can influence the total balance (forest and agricultural policies, spatial planning, construction activity, storms).
- Related indicators
- Carbon balance in forests
The carbon balance of land use can be compared to the data from other countries, given that the emissions and sinks are 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 and the Kyoto Protocol. The methods are consistent with the guidelines of the IPCC (Intergovernmental Panel on Climate Change).
Emissions and sinks caused by land use or changes in land use are recorded for six land-use categories (forest land, cropland, grassland, wetlands, settlements and other land), as well as harvested wood products. In addition to the categories listed here, total emissions include low levels of nitrous oxide which, under international guidelines, cannot be allocated to any of these categories. Carbon dioxide (CO2) is by far the most important greenhouse gas, while methane and nitrous oxide from fires, reservoirs, land-use changes and drained wetlands contribute to a lesser extent to the emissions. The emissions of methane (CH4) and nitrous oxide (N2O) are converted to CO2 equivalents and added to the CO2 emissions.