i'm nancy kruger, deputy director of nacaa, the national association of clean air agencies. thank you for this opportunity to testify and provide preliminary comments for nacaa a epa's proposed aircraft endangerment finding advance notice of proposed rulemaking seeking input on icao's ongoing development of international aircraft standards for co2 and also the potential forthcoming development by epa of aircraft cabin outside the mission standard. nacaa is a national nonprofit nonpartisan association of air pollution control agencies in 41 states, the district of columbia, four territories, and 116 metropolitan areas. our members, professionals and our agencies have asked each to improving air quality in the u.s., and our testimony is based upon that experience. first with respect to the endangerment finding, nacaa commends epa and supports in on its proposal to find that ghg concentration in the atmosphere endanger the public health and welfare of current and future generations within the meaning of section 231(a) of the clean air act, to find that ghg emissions from certai