This report contains a summary of the compilation and synthesis of the fourth biennial reports submitted to the secretariat by Parties included in Annex I to the Convention. It highlights key findings in relation to quantified economy-wide emission reduction targets; progress towards those targets, including information on mitigation actions and their effects, and estimates of emission reductions and removals and the use of units from market-based mechanisms and land use, land-use change and forestry activities; greenhouse gas emission trends and projections; and the provision of financial, technological and capacity-building support to developing country Parties.