An assessment of air pollution and environmental impacts from international maritime transportation including engineering controls and policy alternatives

This dissertation addresses technology-policy issues important in understanding the global distribution of ship propulsion emissions and their control through engineering technologies and policy strategies. Air emissions from ships are shown to be significant at global, regional and local scales. This work presents a geographically resolved, global inventory of emissions from commercial ship engines operating internationally. Global annual NO_x and SO _x emissions from ships are estimated to be 3.08 Tg (1012 grams) as N, and 4.24 Tg as S, respectively, more than 14 percent of nitrogen emissions from global fuel combustion sources and more than 16 percent of sulfur emissions from world petroleum use. Moreover, nearly 70% of ship emissions occur within 400 km of land regions, and 85% occur north of the equator. Other air pollutants and carbon dioxide were estimated in this ship emissions assessment (SEA).; This work presents a national inventory of emissions from commercial ships operating in U.S. waters, indicating that emissions from ships on U.S. inland rivers equal about 70% of the emissions from ships on all three U.S. coastlines combined. On the coastlines, oceangoing vessels account for most of the commercial ship emissions.; Ship sulfur emissions are included in a global chemical transport model to quantify the contribution of these ship emissions on ambient concentrations of sulfur dioxide and sulfate in the marine environment and in coastal regions. By applying the SEA emissions data set for SO₂ and PM emissions from ships within a global chemical transport model, this work concludes that the impact of ship emissions is significant on SO₂ and sulfate concentrations, and on global indirect radiative forcing.; The impacts of proposed regulations to control emissions from new engines are evaluated, with the conclusion that existing marine engines should be considered if air quality objectives are to be met within the next twenty years. Engineering technologies that can be feasibly retrofit on existing engines are identified and their life-cycle costs are estimated. An assessment of policy strategies for reducing emissions from ships is provided. Global policies are found favor the widest range of technology alternatives within various criteria for cost-effectiveness.