Confidence graded mangrove restoration planning reveals constrained blue carbon opportunities and finance limits across the Indo-West Pacific

Mangrove restoration is increasingly promoted as a nature-based pathway for climate mitigation and coastal adaptation, yet restoration targets remain difficult to implement because estimates of recoverable area, ecosystem service gains, and financial feasibility often rely on different assumptions. Here, we developed a confidence graded framework for mangrove restoration planning across the Indo-West Pacific (IWP), the global centre of mangrove diversity and restoration demand. We harmonized three independent lines of evidence, a random forest-derived cover model, a MaxEnt-derived niche model, and a Delphi-based historical-loss restoration layer, within a 1 km coastal decision space. We then quantified fishery support, restoration cost, carbon accumulation rate (CAR), age dependent biomass carbon, and coastal protection benefit to compare ecological restoration priorities with market-based restoration finance pathways. High-confidence opportunities covered only 2,235 km2 and were concentrated in Indonesia, Australia, Myanmar, and Vietnam, indicating that robustly supported restoration space is far smaller than broad suitability estimates imply. Divergence among evidence lines was strongly structured by the Human Development Index, showing that restoration uncertainty is not only biophysical but also socio-economic. Ecological priorities clustered around the South China Sea, whereas market-based scenarios revealed strong financing constraints. Roundwood was the only biomass-use pathway with broad positive net present value under positive discount rates, and carbon-crediting required prices near 50 USD tCO2e-1 to become widely feasible. Our results show that mangrove restoration can contribute to climate mitigation and coastal resilience, but only if restoration targets are filtered by evidence strength, ecosystem service co-benefits, and realistic financing conditions.