Domestic air transport grew in China at 15.5 percent annually from 2001 to 2006. The rate of air travel globally increased at 3.7 percent per year over the same time. In the EU greenhouse gas emissions from aviation increased by 87% between 1990 and 2006. However it must be compared with the flights increase, only in UK, between 1990 and 2006 terminal passengers increased from 100 000 thousands to 250 000 thousands., according to AEA reports every year, 750 million passengers travel by European airlines, which also share 40% of merchandise value in and out of Europe. Without even pressure from "green activists", targeting lower ticket prices, generally, airlines do what is possible to cut the fuel consumption (and gas emissions connected therewith). Further, according to some reports, it can be concluded that the last piston-powered aircraft were as fuel-efficient as the average jet in 2005.
Increasingly since 1978, US airlines have been reincorporated and spun off by newly created and internally led management companies, and thus becoming nothing more than operating units and subsidiaries with limited financially decisive control. Among some of these holding companies and parent companies which are relatively well known, are the UAL Corporation, along with the AMR Corporation, among a long list of airline holding companies sometime recognized worldwide. Less recognized are the private equity firms which often seize managerial, financial, and board of directors control of distressed airline companies by temporarily investing large sums of capital in air carriers, to rescheme an airlines assets into a profitable organization or liquidating an air carrier of their profitable and worthwhile routes and business operations.