Sir,
Today jet aircraft are 70% more fuel efficient then the 1st Generation ones.
In 1990 air transport contributed some 3.5% to global greenhouse gas emissions. Depending on future trends in aviation, technology and the emissions of other sectors, this share may grow to 15% or more (Penner et al. 1999). As improved energy efficiency will directly reduce the CO2 emissions of today’s kerosene-based aviation, it is important to know how aviation energy efficiency has developed historically and what might happen in the future. Mitigation of climate change is a subject of wide and intense debate. Although international air transport has thus far been exempt from the Kyoto Treaty on reducing greenhouse gas emissions, it is becoming increasingly clear that this will not remain so in the future. Past and future gains in aviation fuel efficiency have consequently been widely debated. A commonly cited figure of 70% gains between 1960 and 2000 is widely used as a reference for the industry’s technological achievements (Gössling and Peeters 2005). This figure was published in the IPCC’s Special Report on Aviation and the Global Atmosphere, which included a graph showing trends in the fuel efficiency of new jet aircraft coming onto the market between 1960 and 2000 (Penner et al. 1999; p. 298). It is this graph – reproduced here in Figure 1 – that suggests the figure of 70% overall fuel efficiency gains between 1960 and 2000, and based on this figure the IPCC indeed concludes: “The trend in fuel efficiency of jet aircraft over time has been one of almost continuous improvement; fuel burned per seat in today's aircraft is 70% less than that of early jets”.
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