THE GEOGRAPHY OF TRANSPORT SYSTEMS

Source: Adapted from Aviation and the Global Atmosphere. http://www.grida.no/climate/ipcc/aviation/index.htm
Several factors contributed to the improvements in energy efficiency of aircraft in recent decades. The most significant (Lee et al., 2001) are:
Structural efficiency improvements, such as weight reduction, made no contribution to improved energy efficiency. Rising energy prices have several impacts on airline companies. One involves switching to more fuel efficient aircraft.