Benefit-cost assessment of aviation environmental policies

Abstract

This thesis aids in the development of a framework in which to conduct global benefit-cost assessments of aviation policies. Current policy analysis tools, such as the aviation environmental portfolio management tool (APMT), only consider climate and air quality impacts derived from aircraft emissions within the US. In addition, only landing and takeoff (LTO) emissions are considered. Barrett et al., however, has shown that aircraft cruise emissions have a significant impact on ground-level air quality. Given the time-scale and atmospheric lifetimes of species derived from aircraft emissions at these higher altitudes, a global framework for assessment is required. This thesis specifically investigates the global as well as regional implementation of an ultra-low sulfur jet fuel (ULSJ). The expected result from this policy is a reduction in aircraft SOx emissions, which in turn would reduce the atmospheric burden of primary and secondary sulfate aerosols. Sulfate aerosols have both climate and air quality impacts as they reflect incoming solar radiation (and thus provide atmospheric cooling) and are a type of ground-level pollutant that have generally been correlated to premature mortalities resulting from cardiopulmonary disease and lung cancer. Benefit-cost techniques are applied in this analysis. The framework developed within this thesis includes the ability to calculate expected avoided premature mortalities outside of the US. In addition, a monetization approach is used in which different values of statistical lives (VSLs) are applied depending on the country in which a premature mortality occurs. Also, the economic impact of increased fuel processing to reduce the FSC is estimated. This analysis is performed using Monte Carlo techniques to capture uncertainty, and a global sensitivity analysis (GSA) is utilized to determine the primary sources of uncertainty. The benefit-cost analysis results show that for US and global implementation, there is -80% chance of ULSJ implementation having a not cost beneficial outcome when climate, air quality, and economic impacts are included. On average, however, the air quality benefits do exceed the climate disbenefits. In addition, the GSA reveals that the largest contributor to the uncertainty in this analysis is the assumed US VSL distribution, where approximately 60% of the variance in the final output distribution can be attributed to this uncertainty. In addition, a fast policy tool approach is investigated using sensitivity values calculated from an adjoint model built-in to the global chemical transport model (GCTM) used for the atmospheric modeling within this analysis. From this fast policy tool, first order estimates of the impact of ULSJ on premature mortality are calculated.