The preparation of greenhouse gas emission inventories is the starting point for any robust local climate strategy. The new document from the Joint Research Centre (JRC) provides detailed guidance on how to prepare inventories within the framework of the Covenant of Mayors, integrated into Sustainable Energy and Climate Action Plans (SECAPs). It aims to strengthen the quality, coherence, and comparability of data while maintaining the flexibility required to adapt to diverse municipal contexts.

The manual structures the process around key methodological decisions: defining territorial boundaries, selecting a baseline year, setting emission reduction targets, and choosing between an activity-based or life-cycle approach. The inventory combines activity data—primarily energy consumption—with emission factors, covering buildings, transport, local energy generation, and, as recommended, waste and wastewater.

Beyond the technical calculation, the document highlights the importance of temporal consistency and transparency in documentation to facilitate monitoring through subsequent inventories and to reinforce the credibility of local climate action.