Aviation and the Global Atmosphere

Aviation and the Global Atmosphere
Aviation and the Global Atmosphere
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9.4.3. Environmental Defense Fund Long-Term Scenarios
Other reports in this collection
EDF has produced projections of total traffic demand, fuel use, and emissions through 2100 (Vedantham and Oppenheimer, 1994, 1998). The EDF projections use a
logistic model to simulate the stages of demand growth in aviation markets, focusing particularly on demand growth in developing countries (where aviation has only
recently become a commonplace travel mode). Two sets of aviation demand scenarios-base-level and high-level-describe traffic under each of the six IPCC 1992
scenarios (IS92a through IS92f) for global expectations of gross national product (GNP), population, and emissions (Leggett et al., 1992). Data produced are regional
and global totals.
The model logic incorporates the assumption (based on observation) that latent demand in a region previously not served by airlines will result in an initial period of
rapid growth; once an airport network is in place, business and personal habits will incorporate the new transport option, causing a period of continuing strong growth
rates. Barring unforeseen developments, the experience of some OECD nations suggests that aviation demand will eventually reach maturity, and relative growth rates
will slow as the market approaches saturation. Continued growth of GNP and population imply continuing, albeit slow, growth in demand, even over the very long term.
EDF uses a logistic model with a time-varying capacity to model the dynamics in several sectors
of rapid expansion, continued growth, and eventual slowdown in growth rates without imposing a
zero growth-rate ceiling. Growth rates and market capacities for different regions of the world
were chosen after a review of economic and aviation market history in industrial nations. The
demand model is consistent with the history of the U.S. domestic market.The EDF model sorts
the nations of the world into five economic groups (see Table 9-18). For each of the five
economic groups, the three sectors of civil business passenger, civil personal passenger, and
civil freight are modeled as logistics with time-varying market capacities. The civil business
passenger and civil freight sectors experience logistic expansion toward a time-varying capacity
level that is proportional to the nation's GNP.
The model assumes that expansion in business travel is accompanied by expansion in personal
travel, which includes tourism and leisure visits.Personal travel by air has high income elasticity,
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