Abstract

Achieving the long-term temperature goal of the Paris Agreement requires forest-based mitigation. Collective progress towards this goal will be assessed by the Paris Agreement’s Global stocktake. At present, there is a discrepancy of about 4 GtCO2 yr−1 in global anthropogenic net land-use emissions between global models (reflected in IPCC assessment reports) and aggregated national GHG inventories (under the UNFCCC). We show that a substantial part of this discrepancy (about 3.2 GtCO2 yr−1) can be explained by conceptual differences in anthropogenic forest sink estimation, related to the representation of environmental change impacts and the areas considered as managed. For a more credible tracking of collective progress under the Global stocktake, these conceptual differences between models and inventories need to be reconciled. We implement a new method of disaggregation of global land model results that allows greater comparability with GHG inventories. This provides a deeper understanding of model–inventory differences, allowing more transparent analysis of forest-based mitigation and facilitating a more accurate Global stocktake.

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Acknowledgements

The authors thank J. Pongratz for discussing an early stage of the analysis, V. Korotkov for checking our analysis on Russia, and G. M. Domke for checking our analysis on the United States. J.H. was supported by EU FP7 through project LUC4C (GA603542) and the UK NERC project GGRiLS-GAP. G.G. was supported by Administrative Arrangement Number 340203/2016/742550/SER/CLIMA.A3. A.K.J. was supported by the NSF (AGS 12-43071) and DOE (DE-SC0016323). J.E.M.S.N. was supported by the German Research Foundation’s Emmy Noether Programme (grant number PO1751/1-1). G.G., J.H., G.P.P. and L.P. received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement number 776810 (VERIFY). C.D.K. was supported by the US DOE under Contract DE-AC02-05CH11231 as part of their RGMA (BGC-Feedbacks SFA) and TES Programs (NGEE-Tropics). A.K.J. was supported under the US NSF (NSF-AGS-12-43071).

Author information

Affiliations

  1. Joint Research Centre, European Commission, Ispra, Italy

    • Giacomo Grassi
    • , Alessandro Cescatti
    • , Raul Abad Viñas
    • , Ramdane Alkama
    • , Frank Dentener
    •  & Simone Rossi
  2. Cabot Institute, Department of Geographical Sciences, University of Bristol, Bristol, UK

    • Jo House
  3. Natural Resources Canada, Canadian Forest Service, Victoria, British Columbia, Canada

    • Werner A. Kurz
  4. Woods Hole Research Centre (WHRC), Falmouth, MA, USA

    • Richard A. Houghton
    •  & Alexander A. Nassikas
  5. CICERO Center for International Climate Research, Oslo, Norway

    • Glen P. Peters
  6. Basque Centre for Climate Change (BC3), Bilbao, Spain

    • Maria J. Sanz
  7. Department of Atmospheric Environmental Research, Karlsruhe Institute of Technology, Garmisch-Partenkirchen, Germany

    • Almut Arneth
  8. Mediterranean Institute for Biodiversity and Ecology (IMBE), Aix-Marseille Université, CNRS, IRD, Avignon University, Aix-en-Provence, France

    • Alberte Bondeau
  9. International Centre for Water Resources and Global Change (UNESCO), German Federal Institute of Hydrology, Koblenz, Germany

    • Marianela Fader
  10. Food and Agriculture Organization (FAO) , Rome, Italy

    • Sandro Federici
  11. College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, UK

    • Pierre Friedlingstein
  12. Department of Atmospheric Sciences, University of Illinois, Urbana, IL, USA

    • Atul K. Jain
  13. Institute of Applied Energy (IAE), Tokyo, Japan

    • Etsushi Kato
  14. Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA

    • Charles D. Koven
  15. Climate and Land Use Alliance, San Francisco, CA, USA

    • Donna Lee
  16. Max Planck Institute for Meteorology, Hamburg, Germany

    • Julia E. M. S. Nabel
  17. Foundation Euro-Mediterranean Center on Climate Change (CMCC), Viterbo, Italy

    • Lucia Perugini
  18. College of Life and Environmental Sciences, University of Exeter, Exeter, UK

    • Stephen Sitch
  19. Laboratoire des Sciences du Climat et de l’Environnement, Institut Pierre-Simon Laplace, CEA-CNRS-UVSQ, CE Orme des Merisiers, Gif sur Yvette, France

    • Nicolas Viovy
  20. Met Office Hadley Centre, Exeter, UK

    • Andy Wiltshire
  21. Max Planck Institute for Biogeochemistry, Jena, Germany

    • Sönke Zaehle

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Contributions

G.G. designed the analysis with J.H. and W.A.K., and all three drafted the manuscript. G.G. coordinated all of the inputs, executed the calculations and made the figures. A.C., R.A.H., G.P.P. and M.J.S. contributed to the analysis and provided inputs to the manuscript. F.D. contributed by commenting and editing the manuscript. R.A.V., S.R., S.F. and D.L. contributed to collecting data and information on country GHGIs. R.A. post-processed the DGVM results. R.A.H. and A.A.N. provided data from bookkeeping models. L.P. provided comments on the Global stocktake. A.A., A.B., M.F., P.F., A.K.J., E.K., C.D.K., J.E.M.S.N., S.S., N.V., A.W. and S.Z. provided the original DGVM results and inputs to the manuscript. All authors read and approved the final manuscript.

Competing interests

The authors declare no competing interests.

Corresponding author

Correspondence to Giacomo Grassi.

Supplementary information

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    Supplementary methods and data 1–4, Supplementary analysis and results 5-8, Supplementary tables 1–12, Supplementary figures 1–9, Supplementary references

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https://doi.org/10.1038/s41558-018-0283-x