Intensifying Rice Straw Utilization as a National Mitigation Strategy in Climate- Vulnerable Countries: Evidence from the Philippines

Rice-based agricultural systems in climate-vulnerable countries face the dual challenge of reducing greenhouse gas (GHG) emissions while sustaining food security and rural livelihoods. In the Philippines, approximately 13 million tons of rice straw are generated annually, yet most remains underutilized. While open-field burning has declined to about 12%, the dominant practice is soil incorporation under flooded conditions, which substantially increases methane (CH₄) emissions. Rice cultivation is methane-intensive and accounts for about 12% of national GHG emissions, underscoring the relevance of residue management for near-term mitigation. This study evaluates the mitigation potential and policy relevance of intensified rice straw utilization using a literature-based, scenario-driven modeling framework aligned with the 2019 Refinement to the Intergovernmental Panel on Climate Change (IPCC) Guidelines. National-scale CH₄ mitigation is estimated from diverting rice straw away from open burning and soil incorporation toward off-soil utilization pathways, including fodder, mushroom production, composting, biogas, and biochar. Pathways and baseline allocations were informed by stakeholder roundtable discussions, national statistics, and published emission factors. The model provides a conservative, scenario-based benchmark for estimating CH₄-derived CO₂e reductions and indicative socioeconomic impacts under defined system boundaries, national adoption trajectories, and literature-derived emission factors. Results are intended to inform strategic planning rather than project-level feasibility or investment decisions. Within these constraints, progressively intensified rice straw utilization is estimated to reduce CH₄ emissions by up to 82 Mt CO₂e over ten years and generate an indicative net socioeconomic benefit of approximately USD 3.1 billion. Within the stated assumptions and uncertainty bounds, rice straw management shows potential for integration into the Philippine Nationally Determined Contribution (NDC), subject to site-specific techno-economic assessments, institutional readiness, and adequate monitoring, reporting, and verification (MRV) capacity. Under these conditions, it can function as a scalable Policy and Measure (PAM) supporting circular agriculture, rural livelihoods, and national mitigation planning.