Air traffic management (ATM) affects when, how far, how high, how fast and how efficiently aircraft fly. In turn, this influences how much fuel aircraft burn, the level of greenhouse and other gases emitted from their engines, and how much noise they emit. The environmental performance of aviation has improved dramatically since the 1960s. However, there is still a lot of work to be done in the air transport sector and this is precisely where the SESAR project can and will play a role.