It is over three decades since a large terrestrial carbon sink (ST) was first reported. The magnitude of the net sink is now relatively well known, and its importance for dampening atmospheric CO2 accumulation, and hence climate change, widely recognised. But the contributions of underlying processes are not well defined, particularly the role of emissions from land-use change (ELUC) versus the biospheric carbon uptake (SL; ST = SL − ELUC). One key aspect of the interplay of ELUC and SL is the role of agricultural processes in land-use change emissions, which has not yet been clearly quantified at the global scale. Here we assess the effect of representing agricultural land management in a dynamic global vegetation model. Accounting for harvest, grazing and tillage resulted in cumulative ELUC since 1850 ca. 70% larger than in simulations ignoring these processes, but also changed the timescale over which these emissions occurred and led to underestimations of the carbon sequestered by possible future reforestation actions. The vast majority of Earth system models in the recent IPCC Fifth Assessment Report omit these processes, suggesting either an overestimation in their present-day ST, or an underestimation of SL, of up to 1.0 Pg C a−1. Management processes influencing crop productivity per se are important for food supply, but were found to have little influence on ELUC.
Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research-Atmospheric Environmental Research (IMK-IFU), Kreuzeckbahnstraße 19, 82467 Garmisch-Partenkirchen, Germany;Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research-Atmospheric Environmental Research (IMK-IFU), Kreuzeckbahnstraße 19, 82467 Garmisch-Partenkirchen, Germany;Department of Physical Geographical and Ecosystem Science, Lund University, SE-223 62 Lund, Sweden;Department of Physical Geographical and Ecosystem Science, Lund University, SE-223 62 Lund, Sweden;Department of Earth System Science, School of Earth, Energy and Environmental Sciences, Stanford University, Stanford, CA 94305, USA;Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research-Atmospheric Environmental Research (IMK-IFU), Kreuzeckbahnstraße 19, 82467 Garmisch-Partenkirchen, Germany;Utrecht University, PO Box 80.115, 3508 TC Utrecht, The Netherlands;PBL Netherlands Environmental Assessment Agency, PO Box 303, Bilthoven, The Netherlands;Department of Physical Geographical and Ecosystem Science, Lund University, SE-223 62 Lund, Sweden;Department of Physical Geographical and Ecosystem Science, Lund University, SE-223 62 Lund, Sweden;University of Copenhagen, 1350 Copenhagen, Denmark
Recommended Citation:
T A M Pugh,A Arneth,S Olin,et al. Simulated carbon emissions from land-use change are substantially enhanced by accounting for agricultural management[J]. Environmental Research Letters,2015-01-01,10(12)