Soil organic carbon

Assessment versions

Published (reviewed and quality assured)

• No published assessments

 

Rationale

Justification for indicator selection

Organic carbon in the soil is a dynamic part of the carbon cycle, which includes the atmosphere, water and constituents of the above- and below-ground biosphere. The main source of organic carbon is organisms that synthesise their food from inorganic substances (autotrophic), such as photosynthesising plants. In this process atmospheric carbon is used to build organic materials and enters the soil layers through decomposition and the formation of humus.
Climatic conditions strongly influence both the trends and rates of accumulation and transformation of organic substances in the soil. Increases in temperature and aridity lead to a decrease in the amount of organic carbon in soils in affected areas. Lower levels of organic carbon in the soil are generally detrimental to soil fertility and water retention capacity and tend to increase soil compaction, which leads to increases in surface water runoff and erosion. Other effects of lower organic carbon levels are a depletion of biodiversity and an increased susceptibility to acid or alkaline conditions. The projected changes will accelerate the release of CO₂ from the soil, contributing to higher concentrations in the atmosphere (Janssens, 2004; Bellamy, 2005). The main measures to reduce the detrimental effect of higher temperatures combined with lower soil moisture on the amount of soil organic carbon are changes in land cover and adaptation of land-management practices (Liski et al., 2002; Janssens et al., 2004; Smith et al., 2005, 2006). Under given climatic conditions, grassland and forests tend to have higher stocks of organic carbon than arable land and are seen as net sinks for carbon (Vleeshouwers and Verhagen, 2002). Land-management practices aim at increasing net primary production and reducing losses of above-ground biomass from decomposition. Adaptive measures on agricultural land are changes in farming practices, such as a reduction in tilling or retaining crop residues after harvesting.

Scientific references

• No rationale references available

Indicator definition

• Changes in soil organic carbon content across England and Wales between 1978 and 2003
• Projected changes in soil organic carbon for cropland 1990-2080
  

Units

http://www.eea.europa.eu/publications/eea_report_2008_4/pp111-148CC2008_ch5-7to9_Terrestrial_ecosystems_soil_and_agriculture.pdf

 

Policy context and targets

Context description

In April 2009 the European Commission presented a White Paper on the framework for adaptation policies and measures to reduce the European Union's vulnerability to the impacts of climate change. The aim is to increase the resilience to climate change of health, property and the productive functions of land, inter alia by improving the management of water resources and ecosystems. More knowledge is needed on climate impact and vulnerability but a considerable amount of information and research already exists which can be shared better through a proposed Clearing House Mechanism. The White Paper stresses the need to mainstream adaptation into existing and new EU policies. A number of Member States have already taken action and several have prepared national adaptation plans. The EU is also developing actions to enhance and finance adaptation in developing countries as part of a new post-2012 global climate agreement expected in Copenhagen (Dec. 2009). For more information see: http://ec.europa.eu/environment/climat/adaptation/index_en.htm

Targets

No targets have been specified

Related policy documents

No related policy documents have been specified

 

Methodology

Methodology for indicator calculation

http://www.eea.europa.eu/publications/eea_report_2008_4/pp111-148CC2008_ch5-7to9_Terrestrial_ecosystems_soil_and_agriculture.pdf

Methodology for gap filling

http://www.eea.europa.eu/publications/eea_report_2008_4/pp193-207CC2008_ch8_Data_gaps.pdf

Methodology references

No methodology references available.

 

Data specifications

EEA data references

• No datasets have been specified here.

External data references

• National Soils Inventory (NSI)

Data sources in latest figures

 

Uncertainties

Methodology uncertainty

http://www.eea.europa.eu/publications/eea_report_2008_4/pp193-207CC2008_ch8_Data_gaps.pdf

Data sets uncertainty

http://www.eea.europa.eu/publications/eea_report_2008_4/pp193-207CC2008_ch8_Data_gaps.pdf

Rationale uncertainty

No uncertainty has been specified