Facts & Figures
Emissions of greenhouse gases from land use, land-use change and forestry (LULUCF)
Andreas Gensior, Roland Fuß, Wolfgang Stümer, Sebastian Rüter | 15.08.2022
Net emissions from the LULUCF sector were -11.3 Mt CO2-eq. in 2020. Thus, the sector was a net sink of greenhouse gases. Although the reporting categories cropland, grassland, wetlands and settlements were all more or less pronounced net sources, their emissions were more than compensated by the categories forest and harvested wood products.
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, cropland, grassland, wetlands, settlements, and other land and the 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.
As a particularity of the LULUCF sector, pools can be both, a source of GHG (release → positive emissions) and a sink of CO2 (carbon sequestration → negative emissions).
Net emissions from the LULUCF sector were -11.3 Mt CO2 equivalents (eq.) in 2020. Thus, the sector was a net sink. Forestry provided with -45.8 Mt CO2-eq. the strongest contribution to the net sink, most importantly through its biomass (-29.3 Mt CO2-eq.) and mineral forest soils (-16.0 Mt CO2-eq.). Harvested wood products as a long-term carbon storage also contributed -8.7 Mt CO2-eq. to the sink.
The main counterpart to these sinks are the positive net emissions from areas with agricultural use, i.e., the land-use categories cropland (17.4 Mt CO2-eq.) and grassland (19.2 Mt CO2-eq.). In particular, organic soils in these two categories are a stable and high source of GHG emissions (39.0 Mt CO2-eq.). Emissions from wetlands (5.2 Mt CO2-eq.) and settlements (1.5 Mt CO2-eq.) are also dominated by emissions from organic soils (7.7 Mt CO2-eq.).
Magnitude of the sink varies annually
The 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 – 2005 and 2007, where the LULUCF sector was a net source of 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.), und 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 2018 to 2021) 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 c. 42.3 %, considering only the last reported year (2020, NIR 2022) and the estimate for 2021 by c. 54 %. 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 1999.
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).