Quantification of Greenhouse Gas Emissions from Cigarette Combustion in China

Globally, tobacco is the most extensively cultivated nonfood agricultural commodity. Researchers have used lifecycle assessments to quantify the carbon footprints of tobacco. However, there is an absence of measurement-based experiments on greenhouse gas (GHG) emissions from cigarette combustion, particularly for non-CO2 GHGs. Here, we conducted controlled combustion experiments to quantify emission factors (EFs) for the emissions of CO2, CH4, and N2O generated during cigarette combustion. Results revealed per cigarette EFs of 772–1101 mg for CO2, 30–33 mg for CH4, and 15–25 μg for N2O in China. Based on the EFs, national cigarette combustion in 2022 released 1.88–2.68 teragrams (Tg) of CO2, 0.07–0.08 Tg of CH4, and 36.48–60.80 megagrams of N2O. These emissions account for 0.02–0.03% of national CO2 emissions, 0.12–0.13% of national CH4 emissions, and 0.02–0.03‰ of national N2O emissions, respectively. Cigarette combustion contributed 2.00–2.21 Tg CO2-equivalent over a 100-year time scale, a value 2-fold higher than previous estimates, indicating substantial underestimation in existing research. Scenario analyses further suggest limited potential for reducing GHG emissions through combustion alone. However, opportunities exist to curb tobacco-related emissions in cultivation and curing phases. Our findings provide critical data to address knowledge gaps in the current literature.