Table 1 Summary of the different approaches to estimate CO2 and CH4 fluxes discussed in this study
Dataset | Approach | References |
|---|---|---|
Atmospheric inversions | Optimize net surface fluxes of CO2, CH4 and other trace gases based on in-situ or satellite-based on atmospheric concentration data and using atmospheric transport models. Ancillary flux data (e.g., fossil fuel, lateral fluxes) can be used to adjust inversion-based estimates to estimate natural vs. anthropogenic fluxes. Typically cover the past 2–4 decades | |
Bookkeeping models (BK) | Model carbon losses and gains following LULCC based on land-use/cover type specific C densities and response curves following transitions. Models differ in their parameters, response curves, LULCC forcing used and spatial detail of transitions and fluxes. Typically cover the full industrial period (since 1700) | |
Dynamic global vegetation models (DGVM) | Simulate vegetation productivity, growth, dynamics mechanistically in response to environmental conditions. Some models simulate nutrient cycling and fertilization, fire dynamics, wetland dynamics and methane emissions. Some management practices and shifting cultivation are usually included. FLUC is usually derived as a difference between two simulations, one with fixed land-cover map and another with changing land-cover fields. GCBs cover the period since 1901, in Global Methane Budgets provide data since 2000 | |
National GHG inventories (NGHGI) | Report annually country-level emissions and removals of main greenhouse gases from five categories (energy; industrial processes and product use; agriculture; land use, land-use change and forestry (LULUCF); and waste) and their subsectors since 1990. Follow a common reporting format established by UNFCCC with harmonized methodologies organized in different levels of complexity (Tiers) | (UNFCCC; [37] |
Food and agricultural organization (FAO) | Provide emissions from net forest conversion and fluxes on forest land as well as CO2 emissions from peat drainage and peat fires | [93], FAOSTAT) |