between 1973 and 2018 global airfreight (expressed in ton-kilometers) rose about 12-fold, while scheduled passenger traffic rose from about 0.5 trillion to more than 8.3 trillion passenger-kilometers, nearly a 17-fold gain.[78] Nearly two-thirds (5.3 trillion passenger-kilometers) of the latest total were on international flights—the equivalent of flying nearly half a billion people a year from New York to London and back again.
