Air pollution on high: computer model assesses impact of aviation-related emissions


This article was originally posted July 31 on the web site for the Center for Transportation Studies.

MIT researchers and colleagues are developing a computer model to assess the effects of alternate technology and policy options on aviation-related emissions. Their model will analyze aircraft, airport, regional and global issues in terms of performance, fuel burn, emissions, traffic and traffic growth.

The development of the model, called the System for assessing Aviation's Global Emissions, is driven by the rapid growth in the aviation sector and its associated emissions. In 1992, according to a recent report by the Intergovernmental Panel on Climate Change, air transportation accounted for 2 percent of all the world's man-made carbon dioxide emissions and 13 percent of the fossil fuel used for transportation. Meanwhile, passenger traffic on scheduled airlines has grown by 60 percent in the past 10 years, with an estimated 5 percent increase expected for the next 10 to 15 years. So aviation is and will continue to be an important source of greenhouse gases in the coming decades.

Decreasing those emissions is complicated by certain traits of the aviation industry. The deposition of combustion products in the upper troposphere produces atmospheric effects that are different and generally more significant than those due to ground-based emissions. But "fixing" the technology is problematic because aircraft are more technologically constrained than terrestrial modes of transport, because of their more stringent weight and safety requirements. Furthermore, whatever technical fixes can actually be made will be extremely costly and slow to incorporate because of the large capital costs and long lead times in the aviation industry.

The Committee on Aviation Environmental Protection--an organization of the United Nations--has formed several subcommittees to address environmental emissions. But there is currently no comprehensive, internationally accepted method for determining the impact of aviation-related emissions. In view of the projected growth of the air transportation industry and its unique characteristics, there is clearly need for a computer model that analysts can use to predict and evaluate the effects of different scenarios.

Among the many questions such a model could help to resolve is the fundamental philosophical difference between Europe and the United States on how to approach this problem. In general, Europeans want to increase technological stringency, while the United States wants first to effect as much efficiency as possible with changes in operations, before increasing technical stringency. By providing a tool to predict what emissions will be under various scenarios, the model will inform that debate.

The next meeting of the Committee on Aviation Environmental Protection, focused on emissions, will be held in 2004 or so, by which time the researchers hope to have their model developed enough that others can comment on what they're doing. They can use that feedback to finish the model's development.

Of the 12 people working on the team, four are from MIT. John-Paul Clarke, assistant professor of aeronautics and astronautics, is the principal investigator, working with Professor Ian Waitz, researcher Steve Lukachko and graduate student Bruno Miller. They are collaborating with colleagues from the Volpe National Transportation Systems Center and the Logistics Management Institute. Funding for the MIT portion of the project is from the FAA.

A version of this article appeared in MIT Tech Talk on August 29, 2001.


Topics: Aeronautical and astronautical engineering, Environment and energy

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