Author(s): S. Luyssaert | G. Abril | R. Andres | D. Bastviken | V. Bellassen | P. Bergamaschi | P. Bousquet | F. Chevallier | P. Ciais | M. Corazza | R. Dechow | K.-H. Erb | G. Etiope | A. Fortems-Cheiney | G. Grassi | J. Hartman | M. Jung | J. Lathière | A. Lohila | N. Moosdorf | S. Njakou Djomo | J. Otto | D. Papale | W. Peters | P. Peylin | P. Raymond | C. Rödenbeck | S. Saarnio | E.-D. Schulze | S. Szopa | R. Thompson | P. J. Verkerk | N. Vuichard | R. Wang | M. Wattenbach | S. Zaehle
Journal: Biogeosciences Discussions
ISSN 1810-6277
Volume: 9;
Issue: 2;
Start page: 2005;
Date: 2012;
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Original page
ABSTRACT
Globally, terrestrial ecosystems have absorbed about 30% of anthropogenic emissions over the period 20007–2007 and inter-hemispheric gradients indicate that a significant fraction of terrestrial carbon sequestration must be north of the Equator. We present a compilation of the CO2, CO, CH4 and N2O balance of Europe following a dual constraint approach in which (1) a land-based balance derived mainly from ecosystem carbon inventories and (2) a land-based balance derived from flux measurements are confronted with (3) the atmospheric-based balance derived from inversion informed by measurements of atmospheric GHG concentrations. Good agreement between the GHG balances based on fluxes (1249 ± 545 Tg C in CO2-eq y−1), inventories (1299 ± 200 Tg C in CO2-eq y−1) and inversions (1210 ± 405 Tg C in CO2-eq y−1) increases our confidence that current European GHG balances are accurate. However, the uncertainty remains large and largely lacks formal estimates. Given that European net land-atmosphere balances are determined by a few dominant fluxes, the uncertainty of these key components needs to be formally estimated before efforts could be made to reduce the overall uncertainty. The dual-constraint approach confirmed that the European land surface, including inland waters and urban areas, is a net source for CO2, CO, CH4 and N2O. However, for all ecosystems except croplands, C uptake exceeds C release and us such 210 ± 70 Tg C y−1 from fossil fuel burning is removed from the atmosphere and sequestered in both terrestrial and inland aquatic ecosystems. If the C cost for ecosystem management is taken into account, the net uptake of ecosystems was estimated to decrease by 45% but still indicates substantial C-sequestration. Also, when the balance is extended from CO2 towards the main GHGs, C-uptake by terrestrial and aquatic ecosystems is compensated for by emissions of GHGs. As such the European ecosystems are unlikely to contribute to mitigating the effects of climate change.
Journal: Biogeosciences Discussions
ISSN 1810-6277
Volume: 9;
Issue: 2;
Start page: 2005;
Date: 2012;
VIEW PDF
DOWNLOAD PDF Original pageABSTRACT
Globally, terrestrial ecosystems have absorbed about 30% of anthropogenic emissions over the period 20007–2007 and inter-hemispheric gradients indicate that a significant fraction of terrestrial carbon sequestration must be north of the Equator. We present a compilation of the CO2, CO, CH4 and N2O balance of Europe following a dual constraint approach in which (1) a land-based balance derived mainly from ecosystem carbon inventories and (2) a land-based balance derived from flux measurements are confronted with (3) the atmospheric-based balance derived from inversion informed by measurements of atmospheric GHG concentrations. Good agreement between the GHG balances based on fluxes (1249 ± 545 Tg C in CO2-eq y−1), inventories (1299 ± 200 Tg C in CO2-eq y−1) and inversions (1210 ± 405 Tg C in CO2-eq y−1) increases our confidence that current European GHG balances are accurate. However, the uncertainty remains large and largely lacks formal estimates. Given that European net land-atmosphere balances are determined by a few dominant fluxes, the uncertainty of these key components needs to be formally estimated before efforts could be made to reduce the overall uncertainty. The dual-constraint approach confirmed that the European land surface, including inland waters and urban areas, is a net source for CO2, CO, CH4 and N2O. However, for all ecosystems except croplands, C uptake exceeds C release and us such 210 ± 70 Tg C y−1 from fossil fuel burning is removed from the atmosphere and sequestered in both terrestrial and inland aquatic ecosystems. If the C cost for ecosystem management is taken into account, the net uptake of ecosystems was estimated to decrease by 45% but still indicates substantial C-sequestration. Also, when the balance is extended from CO2 towards the main GHGs, C-uptake by terrestrial and aquatic ecosystems is compensated for by emissions of GHGs. As such the European ecosystems are unlikely to contribute to mitigating the effects of climate change.