- Thesis topic: Constructing Proxy-Based High-Resolution Emission Inventory of Black Carbon as Short-Lived Climate Pollutants in Taiwan: Long-term Variability, Urban Dynamics, and Impacts

- Doi: 

- Abstract: 

        Black carbon (BC) is currently recognized as significant short-lived climate pollutant due to its dual impacts on climate and health. Many organizations have established regional BC emission inventory, but their coarse resolutions are limiting urban-scale investigation. This study presents the first proxy-based high-resolution BC emission inventory for Taiwan during 2000 – 2024 across urban agglomeration city clusters and non-urban areas. CYCU-BC_TEDS inventory database was developed with a 1 km × 1 km and annual resolutions. The estimated nation-level BC emissions (±95% CI) in baseline years were 17,124 t/y (8,924 - 25,377 t/y) in 2003 and 4,290 t/y (2,274 - 6,330 t/y) in 2021. In the same period, the transport sector dominated BC emissions (82.6%), followed by agriculture (9.6%), industry (3.7%), residential (2.5%), and energy (1.6%). Inter-comparisons and Monte Carlo analysis indicated good agreement with regional inventories (MIXv2, REASv3.2, HTAPv3), with differences ranging from -38.6% to +9.9% and uncertainty of 23% – 25%.
At the city level, urban agglomeration clusters contribute >70% of total BC emissions, led by Kaohsiung City (2,656 t/y) and other urban cities, while non-urban counties like Kinmen (162 t/y) and Penghu (375 t/y) showed much lower emissions and distinct sector-specific emission sources. These findings reveal strong spatial heterogeneity and emphasize that BC emission dynamics are shaped by distinct urbanization and land-use policies, underscoring the need for locally specific mitigation strategies to fully address BC’s impacts as short-lived climate pollutants in rapidly urbanizing countries.
Apart from long-term emission sources and urban dynamic analysis, this study also analyzes the potential health impact & climate impacts of long-term BC emission. The integrated assessment of Taiwan’s BC emissions, exposure levels, health burdens, and climate impacts from 2000–2024 revealed three central findings. First, the reduced-form OLS exposure model demonstrated strong predictive skill, with the 20 km buffer radius achieving the highest performance (R2 = 0.52). Population-weighted BC exposure declined by more than 60% over the study period, falling from approximately 3.32 µg/m3 in 2000 to about 1.30 µg/m3 in 2024.
This reduction translated into a substantial decrease in BC-attributable mortality, from 2,546 (95% CI: 1,707–3,169) person per year in 2000 to 369 (95% CI: 246 – 461) person per year in 2024. The attributable mortality fraction dropped from 2.6% to 0.2% over the same period. The climate impact analysis indicates that BC-induced warming has decreased dramatically. BC-driven GWP20 fell from 24.93 x 106 to 5.11 x 106 Mt CO₂-eq per year over the study period. BC-induced GTP10 exhibited the largest absolute reductions, falling from peak values near 7 – 9 x 106 Mt CO2-eq per year in the early 2000s to below 2 x 106 Mt CO2-eq per year in 2024. The established CYCU-BC_TEDS emission inventory demonstrated its potential to be used as initial policy instruments for decision-makers to comprehensively assess the emission trends, sources, urban dynamics, and potential impacts of BC as short-lived climate pollutants.

Keywords: black carbon, climate impacts, emission inventory, emission sources, health impacts, short-lived climate pollutants