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The environmental impact of aviation occurs because aircraft engines emit heat, noise, particulates and gases which contribute to climate change〔(【引用サイトリンク】Aircraft Engine Emissions )〕〔(【引用サイトリンク】What is the impact of flying? )〕 and global dimming.〔 〕 Despite emission reductions from automobiles and more fuel-efficient and less polluting turbofan and turboprop engines, the rapid growth of air travel in recent years contributes to an increase in total pollution attributable to aviation. From 1992 to 2005, passenger kilometers increased 5.2% per year. And in the European Union, greenhouse gas emissions from aviation increased by 87% between 1990 and 2006. There is an ongoing debate about possible taxation of air travel and the inclusion of aviation in an emissions trading scheme, with a view to ensuring that the total external costs of aviation are taken into account.〔(Including Aviation into the EU ETS: Impact on EU allowance prices ) ICF Consulting for DEFRA February 2006〕 ==Climate change== Like all human activities involving combustion, most forms of aviation release carbon dioxide (CO2) and other greenhouse gases into the Earth's atmosphere, contributing to the acceleration of global warming〔Anderson, K. (17 June 2008). (Reframing climate change: from long-term targets to emission pathways ) (esp. slide 24 onward).〕 and (in the case of CO2) ocean acidification.〔McNeil BI, Matear RJ (2008). (Southern Ocean acidification: A tipping point at 450-ppm atmospheric CO2 ). Proceedings of the National Academy of Sciences (105:48; p.18860). (In the Southern Ocean, an ecological tipping point due to "wintertime aragonite undersaturation is projected to occur by the year 2030 and no later than 2038.")〕 These concerns are highlighted by the present volume of commercial aviation and its rate of growth. Globally, about 8.3 million people fly daily (3 billion occupied seats per year), twice the total in 1999.〔Assoc. Press 2014. As air traffic grows, safety at forefront. By S. Mayerowitz, AP Airlines Writer. 2 August 2014〕 U.S. airlines alone burned about 16.2 billion gallons of fuel during the twelve months between October 2013 and September 2014.〔(Why airfare keeps rising despite lower oil prices ), by Scott Mayerowitz, Assoc. Press Airlines Writer. Houston Chron., November 17, 2014.〕 In addition to the CO2 released by most aircraft in flight through the burning of fuels such as Jet-A (turbine aircraft) or Avgas (piston aircraft), the aviation industry also contributes greenhouse gas emissions from ground airport vehicles and those used by passengers and staff to access airports, as well as through emissions generated by the production of energy used in airport buildings, the manufacture of aircraft and the construction of airport infrastructure.〔Horvath A, Chester M (2008). (Environmental Life-cycle Assessment of Passenger Transportation An Energy, Greenhouse Gas and Criteria Pollutant Inventory of Rail and Air Transportation ). Info: University of California Transportation Center, UC Berkeley.〕 While the principal greenhouse gas emission from powered aircraft in flight is CO2, other emissions may include nitric oxide and nitrogen dioxide (together termed oxides of nitrogen or NOx), water vapour and particulates (soot and sulfate particles), sulfur oxides, carbon monoxide (which bonds with oxygen to become CO2 immediately upon release), incompletely burned hydrocarbons, tetraethyllead (piston aircraft only), and radicals such as hydroxyl, depending on the type of aircraft in use.〔 Emissions weighting factor (EWFs) i.e., the factor by which aviation emissions should be multiplied to get the -equivalent emissions for annual fleet average conditions is in the range 1.3–2.9.〔(Valuing the non-CO2 climate impacts of aviation ) Climatic Change, 111 ( 3-4 ) s. 559-579 2012〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「environmental impact of aviation」の詳細全文を読む スポンサード リンク
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