This report assess the current knowledge about CO2 emissions from land use change over the last century. For the previous 25 years, 20% of all anthropogenic CO2 emissions came from LULUCF (Land Use, Land Use Change and Forestry). Most landuse change emissions are from deforestation, but there is great uncertainty in estimating these emissions. The policy implication is that future CO2 emissions from LULUCF, which are difficult to project, will add to other known emissions sources. Knowing the potential for near term emissions reductions depends on reducing the uncertainties in current LULUCF emissions estimates.