Natural carbon sinks currently absorb approximately half of the anthropogenic CO2 emitted by fossil fuel burning, cement production and land-use change. However, this airborne fraction may change in the future depending on the emissions scenario. An important issue in developing carbon budgets to achieve climate stabilisation targets is the behaviour of natural carbon sinks, particularly under low emissions mitigation scenarios as required to meet the goals of the Paris Agreement. A key requirement for low carbon pathways is to quantify the effectiveness of negative emissions technologies which will be strongly affected by carbon cycle feedbacks. Here we find that Earth system models suggest significant weakening, even potential reversal, of the ocean and land sinks under future low emission scenarios. For the RCP2.6 concentration pathway, models project land and ocean sinks to weaken to 0.8 ± 0.9 and 1.1 ± 0.3 GtC yr−1 respectively for the second half of the 21st century and to −0.4 ± 0.4 and 0.1 ± 0.2 GtC yr−1 respectively for the second half of the 23rd century. Weakening of natural carbon sinks will hinder the effectiveness of negative emissions technologies and therefore increase their required deployment to achieve a given climate stabilisation target. We introduce a new metric, the perturbation airborne fraction, to measure and assess the effectiveness of negative emissions.
Met Office Hadley Centre, FitzRoy Road, Exeter, EX1 3PB, UK;Laboratoire des Sciences du Climat et de l’Environnement, CEA CNRS UVSQ, Gif-sur-Yvette, France;Department of Earth System Science, University of California, Irvine, USA;College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter EX4 4QE, UK;Laboratoire des Sciences du Climat et de l’Environnement, CEA CNRS UVSQ, Gif-sur-Yvette, France;Centre International de Recherche en Environnement et Développement, CNRS-PontsParisTech-EHESS-AgroParisTech-CIRAD, F-94736 Nogent-sur-Marne, France;Center for International Climate and Environmental Research—Oslo (CICERO), Gaustadalléen 21, NO-0349 Oslo, Norway;Energy Program, International Institute for Applied Systems Analysis, Schlossplatz 1, A-2361 Laxenburg, Austria;Institute for Atmospheric and Climate Science, ETH Zurich, Universitätstrasse 16, 8092 Zurich, Switzerland;PBL Netherlands Environmental Assessment Agency, The Netherlands;Copernicus Institute for Sustainable Development, Utrecht University, The Netherlands;Global Carbon Project, CSIRO Oceans and Atmosphere Research, GPO Box 3023, Canberra, Australian Capital Territory 2601, Australia;NSW Department of Primary Industries, University of New England, Armidale NSW 2351, Australia;Department of Earth System Science, Woods Institute for the Environment and Precourt Institute for Energy, Stanford University, Stanford, CA 94305, USA;Advanced Systems Analysis Program, International Institute for Applied Systems Analysis, Schlossplatz 1, A-2361 Laxenburg, Austria;Potsdam Institute for Climate Impact Research (PIK), PO Box 60 12 03, D-14412 Potsdam, Germany;University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK;Met Office Hadley Centre, FitzRoy Road, Exeter, EX1 3PB, UK;Stanford University 473 Via Ortega, Stanford, CA 94305-2205, USA;US Carbon Cycle Science Program, US Global Change Research Program, Washington, DC 20006, USA;Institute of Biological and Environmental Sciences, University of Aberdeen, 23 St Machar Drive, Aberdeen, AB24 3UU, UK;Center for International Climate and Environmental Research—Oslo (CICERO), Gaustadalléen 21, NO-0349 Oslo, Norway;Met Office Hadley Centre, FitzRoy Road, Exeter, EX1 3PB, UK
Recommended Citation:
C D Jones,P Ciais,S J Davis,et al. Simulating the Earth system response to negative emissions[J]. Environmental Research Letters,2016-01-01,11(9)