File : D3.8
Author : Julia Pongratz (LMU)
The current BLUE net land use change flux estimate has been published as part of the global annual carbon budget 2018. It includes the originally published parameter set with biomespecific carbon densities and response functions. The land-use forcing is taken from the Land Use Harmonization, LUH2. The model provides data at annual time steps and 0.25 degree resolution, which can be aggregated to country level. The fast track analysis in this deliverable compares BLUE to another bookkeeping approach (Houghton and Nassikas, 2017), to dynamic global vegetation models (DGVMs), and the land use total emissions reported by FAO. Generally higher emission estimates than FAO can be attributed to different ways of reporting/accounting. Likely artifacts of LUH2 are revealed by BLUE and the DGVMs (emission peak due to change in data source in 1950s, sudden increase in variability in 2000, emissions peaks in individual years and countries). Other differences between BLUE and Houghton and Nassikas stem from differences in assumed carbon densities. Since land use forcing and carbon densities will be updated in VERIFY we foresee an improvement in BLUE estimates in the coming years.
