The European Carbon and Greenhouse Gas Balance Revisited

• Published in: Global change biology 2010-03, Vol.C (B)
• Main Authors: Schulze, E.-Detlef, Ciais, Philippe, Luyssaert, Sebastiaan, Schrumpf, Marion, Janssens, Ivan A, Thiruchittampalam, Balendra, Theloke, Jochen, Saurat, Mathieu, Bringezu, Stefan, Lelieveld, Jos, Lohila, Annalea, Rebmann, Corinna, Jung, Martin, Bastviken, David, Grassi, Giacomo, Leip, Adrian, Freibauer, Annette, Kutsch, Werner L, Don, Axel, Nieschulze, Jens, Börner, Annett, Gash, John, Dolman, a J (han)
• Format: Article
• Language: English
• Subjects: Ocean, Atmosphere; Sciences of the Universe
• ISSN: 1354-1013; 1365-2486
• DOI: 10.1111/j.1365-2486.2010.02215.x

In an overview of the European carbon, greenhouse gas and non-GHG fluxes, gross primary productivity, GPP, is about 9.3 Pg yr-1, and fossil fuel imports are 1.6 Pg yr-1. GPP is about 1.25% of solar radiation, containing about 360 1018 J energy, which is five times as high as the energy content of the annual fossil fuel use (75 1018 J yr-1). Net primary production, NPP, is 50%, terrestrial net biome productivity, NBP, is 3%, and the net greenhouse gas balance, NGB, is 0.3% of GPP. The net yield of human land use is 20% of NPP or 10% of GPP, or alternatively 1 ‰ of solar radiation after accounting for the inherent cost of agriculture and forestry for fossil fuel used during operations, for production of pesticides and fertilizer and for the carbon equivalent cost of GHG emissions. About 2.4% of the fertilizer input is converted into N2O. Agricultural emissions are 50% of total methane and NO, 70% of total N2O, and 95% of total NH3 emissions. European soils are a net C sink (114 Tg yr-1), but considering the emissions of GHGs, soils are a source of about 26 Tg CO2 C-equivalent yr-1. Forest, grassland and sediment sinks are offset by GHG emissions from croplands, peat-lands and inland waters. Non-GHGs (NH3, NOx) interact significantly with the GHG and the carbon cycle through ammonium-nitrate aerosols and dry deposition. Wet deposition of nitrogen support about 50% of forest timber growth. Land use change is regionally important with large unidirectional fluxes totalling about 50 Tg C yr-1. Nevertheless, for the European tracegas-balance, land-use intensity is more important than land-use change. Obviously, it is not sufficient to investigate the carbon cycle as an isolated entity, because associated emissions of GHGs and non-GHGs significantly distort the carbon cycle and compensate apparent carbon sinks.