FAA Administrator Marion Blakey said last month in a speech to an emissions colloquium at ICAO in Quebec that “aircraft greenhouse-gas emissions might become a serious barrier to aviation growth long-term.” Also at the colloquium, Massachusetts Institute of Technology professor Ian Waitz presented preliminary research that says in one estimation, aviation emissions may result in a few hundred premature deaths a year and contribute to climate costs by $16 billion annually. But, Waitz said, “There is a very positive side to the story.” He emphasized that while aviation accounts for approximately 3 percent of America’s fuel burn, the rate of premature deaths as a result of the emissions is only “a small fraction of one percent” of the yearly total attributed to poor local air quality. Waitz added that there has been a 95–percent reduction in the number of people affected by aviation noise in the last 30 years despite a massive increase in air travel.