National and city-level greenhouse gas inventories in developing countries: status, gaps, and pathways forward

Accurate greenhouse gas (GHG) inventories are essential for tracking climate mitigation. While many developed countries now publish comprehensive and timely emission inventories, developing countries still face data, time and resource constraints that hinder inventory development. This paper reviews the status of national and city-level GHG inventories in developing countries. We outline the main GHG accounting methods and examine their application in developing countries. We then assess the uneven geographic coverage of inventories at national and city scales and analyze the challenges faced in these contexts. Sparse city-level coverage across developing countries reflects gaps in basic activity data, a lack of locally specific emission factors and inconsistent accounting boundaries that limit comparability. Additionally, many existing inventories are outdated and insufficiently transparent, limiting their usefulness for policy design and evaluation. Emerging techniques such as machine-learning and atmospheric-science based approaches remain constrained by data limitations, observation coverage and limited knowhow. Inventory improvement in developing countries should prioritize routine core data collection, transparent documentation, targeted sectoral and facility-level detail, careful evaluation of non-state data products and task-specific use of advanced methods. Sustained institutional capacity and long-term data stewardship are therefore central to closing the inventory gaps.