Abstract

The projected increase in global air traffic raises concerns about the potential impact aviation emissions have on climate and air quality. Aviation emissions modify the chemical and physical properties of the atmosphere in a variety of ways. Aviation contributed roughly 5% of the total human-related radiative forcing (RF) on climate for the year 2005 (if one assumes the RF from different emissions is additive, which it really isn’t). Overall, the effects of aviation emissions on climate remain poorly understood. In this research, various aspects of aviation effects on climate and air quality are explored with resulting significant improvements of understanding in some key areas. Three-Dimensional Chemical-Climate Models (CCMs), namely CAM5 -Chem, the atmospheric components of the Community Earth System Model (CESM) were used to calculate the aviation-induced current day and future climate and air quality impacts. Aviation current emissions data were obtained from Federal Aviation Administration (FAA) and future emissions data were obtained from other FAA supported analyses that consider the demand forecast for aviation in development of future scenarios. In our studies, we have evaluated the aviation-induced effects on climate using the concept of radiative forcing. Remaining uncertainties are also calculated and evaluated. Moreover, special analyses were done to examine specific sources of uncertainty. In addition, the impacts of aviation emissions occurring outside of airports (e.g., in flight outside the boundary layer) on the surface air quality are also calculated and discussed.