Harmonising the land-use flux estimates of global models and national inventories for 2000–2020
[2];
[3];
[4];
[6];
[1];
[7];
[8];
[9];
[10];
[2];
[12];
[14]
more »
- European Commission, Ispra (Italy). Joint Research Centre
- Ludwig Maximilian Univ. of Munich, Munich (Germany)
- International Institute for Applied Systems Analysis (IIASA), Laxenburg (Austria)
- Woodwell Climate Research Center, Falmouth, MA (United States)
- Univ. of Exeter, Devon (United Kingdom)
- Commonwealth Scientific and Industrial Research Organisation (CSIRO), Canberra, ACT (Australia)
- Centre National de la Recherche Scientifique (CNRS) (France); Alternative Energies and Atomic Energy Commission (CEA) (France); Institut Pierre Simon Laplace, Gif‐sur‐Yvette (France). Laboratoire des Sciences du Climat et de l'Environnement
- Institute for Global Environment Strategies, Hayama (Japan)
- Univ. of Exeter, Devon (United Kingdom); Centre National de la Recherche Scientifique (CNRS) (France); Institut Pierre Simon Laplace, Gif‐sur‐Yvette (France)
- Natural Resources Canada, Victoria, BC (Canada)
- Univ. of the Basque Country (Spain). Basque Center for Climate Change (BC3); Basque Foundation for Science, Bilbao (Spain). IKERBASQUE
- Institute of Applied Energy, Tokyo (Japan)
- National Center for Atmospheric Research (NCAR), Boulder, CO (United States)
- Univ. of Western Sydney, NSW (Australia). Hawkesbury Inst. for the Environment
- Max Planck Institute for Biogeochemistry, Jena (Germany); Max Planck Institute for Meteorology, Hamburg (Germany)
- NASA Goddard Space Flight Center (GSFC), Greenbelt, MD (United States)
- Yu. A. Izrael Institute of Global Climate and Ecology (IGCE), Moscow (Russia)
- Boston College, Chestnut Hill, MA (United States)
- Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
- Sun Yat-Sen Univ., Guangzhou (China)
- Nanjing Univ. of Information Science and Technology (China)
- Ludwig Maximilian Univ. of Munich, Munich (Germany); Max Planck Institute for Meteorology, Hamburg (Germany)
As the focus of climate policy shifts from pledges to implementation, there is a growing need to track progress on climate change mitigation at the country level, particularly for the land-use sector. Despite new tools and models providing unprecedented monitoring opportunities, striking differences remain in estimations of anthropogenic land-use CO2 fluxes between, on the one hand, the national greenhouse gas inventories (NGHGIs) used to assess compliance with national climate targets under the Paris Agreement and, on the other hand, the Global Carbon Budget and Intergovernmental Panel on Climate Change (IPCC) assessment reports, both based on global bookkeeping models (BMs). Recent studies have shown that these differences are mainly due to inconsistent definitions of anthropogenic CO2 fluxes in managed forests. Countries assume larger areas of forest to be managed than BMs do, due to a broader definition of managed land in NGHGIs. Additionally, the fraction of the land sink caused by indirect effects of human-induced environmental change (e.g. fertilisation effect on vegetation growth due to increased atmospheric CO2 concentration) on managed lands is treated as non-anthropogenic by BMs but as anthropogenic in most NGHGIs. We implement an approach that adds the CO2 sink caused by environmental change in countries' managed forests (estimated by 16 dynamic global vegetation models, DGVMs) to the land-use fluxes from three BMs. This sum is conceptually more comparable to NGHGIs and is thus expected to be quantitatively more similar. Our analysis uses updated and more comprehensive data from NGHGIs than previous studies and provides model results at a greater level of disaggregation in terms of regions, countries and land categories (i.e. forest land, deforestation, organic soils, other land uses). Our results confirm a large difference (6.7 GtCO2 yr—1) in global land-use CO2 fluxes between the ensemble mean of the BMs, which estimate a source of 4.8 GtCO2 yr—1 for the period 2000–2020, and NGHGIs, which estimate a sink of —1.9 GtCO2 yr—1 in the same period. Most of the gap is found on forest land (3.5 GtCO2 yr—1), with differences also for deforestation (2.4 GtCO2 yr—1), for fluxes from other land uses (1.0 GtCO2 yr—1) and to a lesser extent for fluxes from organic soils (0.2 GtCO2 yr—1). By adding the DGVM ensemble mean sink arising from environmental change in managed forests (—6.4 GtCO2 yr—1) to BM estimates, the gap between BMs and NGHGIs becomes substantially smaller both globally (residual gap: 0.3 GtCO2 yr—1) and in most regions and countries. However, some discrepancies remain and deserve further investigation. For example, the BMs generally provide higher emissions from deforestation than NGHGIs and, when adjusted with the sink in managed forests estimated by DGVMs, yield a sink that is often greater than NGHGIs. In summary, this study provides a blueprint for harmonising the estimations of anthropogenic land-use fluxes, allowing for detailed comparisons between global models and national inventories at global, regional and country levels. This is crucial to increase confidence in land-use emissions estimates, support investments in land-based mitigation strategies and assess the countries' collective progress under the Global Stocktake of the Paris Agreement.
- Research Organization:
- Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE
- Grant/Contract Number:
- AC05-00OR22725
- OSTI ID:
- 2283827
- Journal Information:
- Earth System Science Data (Online), Vol. 15, Issue 3; ISSN 1866-3516
- Publisher:
- Copernicus PublicationsCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Similar Records
Critical adjustment of land mitigation pathways for assessing countries' climate progress
Global Carbon Budget 2022