Improving estimations of GHG emissions and removals from land use change and forests in Brazil

Brazil ranks fifth in greenhouse gas emissions globally due to land use change. As a signatory to the Paris Agreement, Brazil must periodically report its GHG emissions as well as present mitigation targets set in the Nationally Determined Contribution (NDC). The SEEG Brazil Initiative (Greenhouse Gas Emission and Removal Estimating System) generates independent estimates of GHG emissions and removals since 2013, and in 2020, the estimation method for the land use change sector has been improved. This study aimed to (1) present these methodological advancements, including the spatial allocation of annual emissions and removals due to land use change (LUC) in Brazil at a 30 m spatial scale, and (2) explore the emission and removal patterns observed in Brazil from 1990 to 2019. The method presented here is built upon-but improves-the approach used by Brazil's official National Inventories to estimate GHG emissions and removals. The improvements presented here include exploring emissions to the municipality level and using an annual updated time series of land use and land cover maps. Estimated greenhouse gas emissions from the LUC sector ranged from 687 Mt of CO2e in 2011 to a peak of 2150 Mt of CO2e in 2003. In 2010, removals nearly offset gross emissions in the sector, with a net emission of 116 Mt of CO2e. The trend observed in recent years was an increase in emissions, decreasing Brazil's likelihood of meeting its NDC targets. Emission profiles vary across the country, but in every biome, the conversion of primary native vegetation is the predominant transition type. If Brazil managed to curb deforestation, the total GHG emissions from the land use change sector would decrease by 96%, mitigating around 44% of total emissions.