Environmental impact assessment of commercial aircraft operations in the United States

Abstract

The objective of this thesis was to evaluate the environmental trade-offs inherent in multi-criteria objectives of an integrated environmental policy. A probabilistic multi-attribute impact pathway analysis (MAIPA) was formulated to assess the environmental damages of US commercial aircraft operations from 1991-2003. The initial contribution of this work was demonstrating the feasibility of, and identifying requirements for, the FAA Aviation-environmental Portfolio Management Tool (APMT), an integrated assessment capability for US regulatory decision-making. Non-aircraft sources have been found to dictate marginal emissions costs. The implication is that aviation emissions reductions influence neither the magnitudes nor trends in per-unit marginal damages. In contrast, noise mitigation is the dominant influence on the value of per-unit marginal damages. Trends in sum damages were found to depend on the growth rates of air transport relative to other source emissions. Growth in air transport emissions outpaced non-aircraft sources from 1991-2003. Because growth in marginal costs is nonlinear over this period, aviation emissions damages grow faster than inventories. Applying methods similar to MAIPA to estimate damages for future scenarios suggests that stemming climate impacts is fast becoming the priority. A reassessment of the environmental benefits derived from mandated phase-outs of noisy aircraft during the 1990's has been carried out. Previous studies estimated a -80% reduction in population exposure. In contrast, the reassessment estimates a ~2% reduction, providing benefits 17-20 times lower than published estimates of abatement costs.

(cont.) The primary environmental benefit of the noise phase-outs was found to be related to reductions in particulate matter inventories. One way to avoid trade-off inefficiencies is to identify options that bundle benefits. This action provides such an example, where the phase-outs led to reductions in both noise and air quality emissions. Other contributions in the thesis include the following: a treatment of air transport particulate matter emissions, environmental fate, and health impacts of particulate matter; identification that the major source of reducible uncertainty in emissions damages stems from the assumed extent of ozone and particulate matter production in the engine exhaust plume; and quantification of the environmental tradeoffs in decisions specifying aircraft performance for the technology in the US commercial fleet from 1991-2003.