Facts & Figures
Emissions of greenhouse gases from land use, land-use change and forestry (LULUCF)
Andreas Gensior, Sophie Drexler, Roland Fuß, Wolfgang Stümer, Sebastian Rüter | 15.04.2024
In 2022, the net greenhouse gas emissions from the LULUCF sector amounted to 4.4 million tonnes (Mt) carbon dioxide – equivalents (eq.). The sector thus acted as a source of greenhouse gases.
The change from sink to source is due to the fact that the sink function of the reporting categories forest land and harvested wood products was overcompensated by the source functions of the land use categories cropland, grassland, wetlands and settlements. In terms of carbon stocks, organic soils are the main source of the sector, forest biomass is the main sink. The dominant greenhouse gas is carbon dioxide (CO2).
In the LULUCF sector anthropogenic emissions of greenhouse gases (GHG) are reported, which result from Land Use, Land-Use Change and Forestry. Emissions from agricultural activities are reported separately. The inventory distinguishes emissions of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) from the land-use categories forest land, cropland, grassland, wetlands, settlements, and other land and from the pools organic and mineral soils, above-ground and below-ground biomass, deadwood and litter. Furthermore, the carbon stock in harvested wood products is reported as well as emissions from artificial waterbodies, wildfires, and industrial peat extraction.
In the LULUCF sector, pools can act both as a source (release → positive emissions) of greenhouse gases and as a sink (carbon capture → negative emissions) for CO2.
Time series of GHG emissions (sum of CO2, CH4, and N2O in Mt CO2 equivalents) from the LULUCF sector since 1990, stratified by land use categories (source: National Inventory Document 2024); sources are positive, sinks are negative
In 2022, net emissions due to land use, land use change and forestry amounted to 4.4 million tonnes (Mt) CO2-eq. The LULUCF sector thus acted as a source.
With emissions of -39.7 Mt CO2-eq. the land use category forest land is the main contributor to the carbon stock of the LULUCF sector, in particular through biomass (-30.0 Mt CO2-eq) and mineral forest soils (-9.3 Mt CO2-eq). Carbon storage in harvested wood products also acts as a sink amounting to -4.0 Mt CO2-eq.
This is mainly contrasted by the positive net emissions from the agriculturally used areas of the land use categories cropland (15.6 Mt CO2-eq.) and grassland (21.1 Mt CO2-eq.). These two categories show consistently high emissions from drained organic soils over the years (39.8 Mt CO2-eq.).
The net emissions of the land use categories wetlands (9.7 Mt of CO2 eq.) and settlements (0.65 Mt of CO2 eq.) are also strongly influenced by emissions from organic soils (7.1 Mt of CO2 eq.). Another important source of emissions in the land use category wetlands are artificial waters (e.g. reservoirs, fish ponds...) and flowing waters (e.g. drainage ditches...), with annual methane emissions of 4.8 Mt CO2-eq.
Time series of GHG emissions (sum of CO2, CH4, and N2O in Mt CO2 equivalents) from the LULUCF sector since 1990, stratified by pools (source: National Inventory Document 2024); sources are positive, sinks are negative
Magnitude of the sink varies annually
LULUCF emissions over time highlight the strong variation of net emissions. The changes in total emissions mainly reflect the changing net emissions from forests. The high amplitudes and occasional rapid changes in trend result from changing demands for wood and corresponding wood prices as well as extreme weather events (storms and droughts) and corresponding calamities (pest infestations). These mainly impact carbon storage in forest biomass, which is the largest net sink of the sector and largely compensates the stable and high emissions from organic soils.
The exception are the years 1990, 2002 – 2007, 2018 – 2022 where the LULUCF sector was a net source for GHG. This was caused primarily by increased logging due to (1) salvage logging after calamities and (2) exceptionally high demand for wood by the markets.
The German Climate Change Act requires an increasing net sink over time from the LULUCF sector. As a contribution to climate-protection goals, the law assigns to the LULUCF sector absolute amounts of net emissions for the years 2030 (-25 Mt CO2-eq.), 2040 (-35 Mt CO2-eq.), and 2045 (-40 Mt CO2-eq.). However, there are no annual commitments between these years. Net emissions for accounting are the mean of emission of the accounted year and the three preceding years. Accounting is done based on a preliminary but more timely estimate for the previous year, for which not all final statistical data are available yet.
The current accountable net emission (calculated according to the accounting rules as mean of 2020 to 2023) misses the target value of the Climate Change Act for 2030 (-25 Mt CO2-eq.) by a significant margin. In this four-year average the net sink of the LULUCF sector is too low by 117 %. The reason for this is the current decline of the LULUCF sink due to forest damage from the drought in recent years. Overall, the goal for 2030 had only been achieved in the time period 1994 to 1996.
Comparison of the time series of net emissions (sum of CO2, CH4 and N2O in million t CO2-eq.; positive: source; negative: sink) of the LULUCF sector (1990-2022: National Inventory Document [NID]; 2024: previous year's estimate [VJS]) with the targets of the Federal Climate Protection Act (KSG §3a); key years are 2030, 2040 and 2045.
There are two anthropogenic impacts on sequestration of carbon in the biogeosphere and mitigation of GHG emissions in the LULUCF sector:
- Protection of existing storage: Avoiding all activities that result in release of carbon from existing storage (such as wetland drainage and grassland conversion).
- Measures that achieve a permanent carbon accumulation in compartments of the biogeosphere:
- Regulated rewetting of organic soils can reduce GHG emissions effectively and can also remove CO2 from the atmosphere and fix it in soil for centuries. This also results in co-benefits, e.g., for biodiversity, landscape hydrology, micro-climate. Furthermore, the cultivation of reed, peat mosses and woody plants on rewetted areas for production of renewable materials offers an additional potential to mitigate GHG emissions by substituting materials that cause GHG emissions during production, use or disposal (insulation materials, fossil fuels and so on).
- Cultivation of woody plants in the agricultural landscape, such as agroforestry, short-rotation coppices, and hedges, results on carbon storage in the woody plant biomass and also often in increasing humus storage and substitution of fossil fuels. Further positive environmental impacts (increased biodiversity, reduced erosion and so on) are initiated. These impacts are medium- to long-term.
- Afforestation and sustainable forest use: Forest biomass store large amounts of carbon and therefore new forest areas always result in increased carbon storage. The sustainable use of forests and the corresponding use of harvested wood products also contributes to climate protection: carbon is stored on wood products medium- to long-term and fossil fuels are substituted.
There are numerous measures for carbon sequestration in mineral soils used for agriculture, e.g., cultivation of catch and cover crops, wildflower strips, crop sequences that increase humus storage, cultivation of perennial plants, optimized fertilization with organic fertilizers, alternating land-use as cropland and grassland and so on. However, suitability of these measures is limited because their effects can be reversed easily and rapidly, e.g., by not continuing them. There is a need for research regarding the long-term effect of technical mitigation measures (such as application of biochar).
