The Paris Climate Agreement has put forests at the center of the stage. According to the countries’ pledges, forests will account for about 25% of the global greenhouse gas (GHG) emissions reductions planned for 2030. However, to achieve and track this mitigation potential, greater transparency and confidence is needed in how forest GHG emission estimates are made. Furthermore, there is also an urgent need to reconcile the differences between the GHG estimates provided in the country reports and those based on scientific assessments. There are many possible reasons for these differences, including different perspectives on what is “anthropogenic sink”. Reconciling these differences will require an unprecedented effort in gaining mutual understanding and cooperation between the scientific community and the developers of national GHG inventories. This is a key opportunity for science-based support to policy. It is also a necessity, as the `Global stocktake’ of progress towards achieving the long-term goals of the Paris Agreement will be based on both country reports and scientific assessments made by the Intergovernmental Panel on Climate Change (IPCC). Without speaking the same language, conflicting numbers and messages are likely to appear in the coming years, and progress towards the “below 2°C” target, including the “balance between anthropogenic GHG emissions and removals in the second half of the century”, cannot be properly assessed.
[Giacomo Grassi leads the LULUCF+ group in the JRC Bio-economy unit. His expertise is in the Land Use, Land Use Change and Forestry (LULUCF) sector, in accounting it in the EU greenhouse gas inventory, in monitoring and reporting issues and in supporting EU policy makers during EU and UNFCCC negotiations related to forests]