Seeing the forest for the plastic trees: a model-driven visualisation framework for material flow analysis.

Reducing plastic pollution requires data to inform policy, guide mitigation measures, and support monitoring. However, plastic- and waste-related data, both within and across countries, remain highly fragmented and lack consolidation. In this study, we consolidated data across the plastics lifecycle and the municipal solid waste (MSW) system into a national-level exploratory baseline Material Flow Analysis (MFA) visualisation for six case-study countries. We also introduce a comparative Indicator Development Stage (IDS) Model that constructs a relative benchmark for comparative readiness, enabling the assessment of data availability across nations. Cabo Verde (64%), Guinea-Bissau (63%), São Tomé and Príncipe (59%), Senegal (67%), Sierra Leone (66%), and Sri Lanka (64%) achieved comparable overall scores, though they are each missing some core indicators (above 76%). Although variability exists across lifecycle stages, overall data availability across the six countries falls within a moderate range from a policy monitoring perspective. This indicates that existing data are sufficient to establish a robust baseline for tracking future data improvement and mitigation tracking. These results demonstrate that, despite the absence of harmonised methodology or common units, sufficient data exist to provide a visual framework for a baseline system-level analysis of the plastic lifecycle, even within data-scarce contexts.