Damage-Intensity Prioritisation of Agricultural-Residue Burning: Spatially Explicit Health, Economic and Climate Co-Benefits of Residue Diversion in Northern Thailand

Air-pollution source control is usually prioritised by emission mass, yet the health damage per tonne emitted varies widely in space. Using agricultural-residue open burning in Northern Thailand as a case study, we couple a GIS emission inventory with a province-resolved damage-function health model to quantify the health and economic burden, quantify how the health damage per tonne emitted varies across provinces, and apportion the co-benefits of diverting residue from open burning between air-quality and climate gains. In 2018, residue burning released about 21 kt of PM2.5, 3.0 kt of black carbon and 0.84 Mt CO2-eq of net non-biogenic greenhouse gases (methane and nitrous oxide), together with 6.2 Mt of biogenic CO2 that is refixed by the following crop and is not a net climate source, with rice, sugarcane and maize contributing 39%, 35% and 20% of fine particles respectively, imposing costs of 59,600 disability-adjusted life years (DALYs; 97.5% from primary PM2.5) and ~USD 1.07 billion per year. The damage caused per tonne emitted varied 4.8-fold among provinces (1.43–6.85 DALY per tonne of PM2.5), so the largest emitter (Nakhon Sawan) was not the province whose emissions caused the largest attributable burden (Phetchabun); damage-weighted prioritisation therefore identifies where diversion yields the greatest benefit. Diverting rice and maize residue avoided 12 kt PM2.5, 1.6 kt black carbon and 0.56 Mt CO2-eq of net greenhouse gas, and 60% of the health and economic burden; extending diversion to sugarcane raised these to 20 kt, 2.9 kt, 0.79 Mt CO2-eq and 95% (USD 1.02 billion per year), so a three-crop strategy is required. Rice-only and maize-only diversion were not clearly separable (rice-only was larger in 64% of the Monte Carlo draws).