CO2 from Land Use (LUCF)
Historical emissions (1850-2012) from LUCF (Land Use Change and Forestry) in the Reference Calculator Database are generated from multiple sources, as no authoritative, country-level dataset exists. The total global LUCF budget is constrained to match the figures published by the Global Carbon Project (GCP).[13] Regional values 1850-2005 are constrained to meet the ten regional budgets published by CDIAC, the so-called Houghton dataset;[14] that is the relative emissions in each region are scaled such that the sum of all regions matches the global total from GCP. National budgets are derived from the relative shares of regional totals either in the MATCH database[15] or in data reported to the UNFCCC (annual reporting for Annex 1 countries 1990-2010, National Communications for some non-Annex I countries for selected years).[16]