Forest carbon sinks and sources

Removals and emissions of greenhouse gasses are determined by natural disturbances and forest management activities.

Forest carbon sinks

Forests act as a carbon sink, where the uptake, or removal of carbon from the atmosphere, exceeds the amount of carbon released.

Forest carbon sources

Forests are considered sources when they emit more than they remove.

Forests emit carbon through respiration and decay when disturbances (harvesting, fires, insects, storms, droughts and floods) occur. Forest fires and other disturbances cause rapid and significant emissions of CO2, as well as methane and nitrous oxide.

The annual net additional CO₂ to the total storage is small (1-2% per year) compared to the existing carbon storage in the forest biomass and soils. It explains why it is so difficult to measure the net carbon sink or source of a forest.

Development of the carbon sink in EU forest biomass and soils since 1990

European forests act as a carbon sink as more carbon is absorbed than released.
Forest carbon sink fluctuates significantly due to a variety of reasons. Reductions may be caused by storm damages as in 2007, rising by harvesting reduction as in 2009 and 2010 during the economic crisis.
How large a sink can be expected from EU forests will depend on the use and management of Europe's forests, impacts of climate and intensity and frequency of other disturbances.
Over the last ten years, the total carbon sinks from forests and soils in Europe have decreased.

Note:

  1. The "deforestation" includes only the results from Forest land converted to Cropland, Grassland, Settlements and Other land
  2. The figures show the net values which are the sum of the gain and losses.

EU27: net emissions and removals from total forest land 1990-2019, kt CO2

 

EU27: net emissions and removals from afforestation and forest remaining forest 1990-2019, kt CO2

 

Carbon stocks in forest biomass

The amounts of carbon stored in forests differ greatly across Europe. Most carbon in biomass in Europe is stored in Central Europe where around 92 tonnes C/ha is stored, while in Southern Europe around 40 tonnes C/ha is stored.

Carbon stocks in forest biomass 1990-2020 and the annual change, Mt C

*Mt C-stock -Million tonnes Carbon stock

 

Source: Extracted from State of Europe’s Forests 2020 Report - Forest Europe published by Ministerial Conference on the Protection of Forests in Europe

Total forest biomass carbon stocks by region 1990-2020, Mt C

 

Annual change in total forest biomass carbon stocks by region

The carbon stock is highest in North and Central-West. The major reason for the observed changes is that growth exceeded cuttings and mortality.

Central-East Europe experienced the largest annual changes in carbon stocks in biomass from 1990 to 2020. For the EU27, it amounts to +90.2 Mt C per year for the period 1990-2020 and to +118 Mt C per year for the period 2010-2020.

Annual percent change in total forest biomass carbon stocks by region, 1990-2020, %

 

Net removals and emissions from different carbon pools

The time carbon persist in a certain pool differs. While the carbon in fresh litter can be released to the soil or atmosphere in months or years, carbon stored in deadwood can remain there for decades.

EU27: net emissions and removals from various carbon pools 1981-2017, kt CO2