Emission Measurements from Traditional Biomass Cookstoves in South Asia and Tibet

Traditional biomass stoves are a major global contributor to emissions that impact climate change and health. This paper reports emission factors of particulate matter (PM2.5), carbon monoxide (CO), organic carbon (OC), black carbon (EC), optical absorption, and scattering from 46 South Asian, 48 Tibetan, and 4 Ugandan stoves. These measurements plus a literature review provide insight into the robustness of emission factors used in emission inventories. Tibetan dung stoves produced high average PM2.5 emission factors (23 and 43 gkg-1 for chimney and open stoves) with low average EC (0.3 and 0.7 gkg-1, respectively). Comparatively, PM2.5 from South Asian stoves (7 gkg-1) was in the range of previous measurements and near values used in inventories. EC emission factors varied between stoves and fuels (p < 0.001), without corresponding differences in absorption; stoves that produced little EC, produced enough brown carbon to have about the same absorption as stoves with high EC emissions. In Tibetan dung stoves, for example, OC contributed over 20% of the absorption. Overall, EC emission factors were not correlated with PM2.5 and were constrained to low values, relative to PM2.5, over a wide range of combustion conditions. The average measured EC emission factor (1 gkg-1), was near current inventory estimates.