Coastal Post Online:Polluting The Friendly Skies - by Edward W.Miller
Polluting The Friendly Skies - by Edward W.Miller
Scientists say water vapor is the most interactive effluent exerting a strong impact on atmospheric temperatures. Most jet exhaust is produced at subsonic cruise altitudes in the upper troposphere and mostly in the northern hemisphere-especially over the US, Western Europe and Japan. A 1998 NASA study of jet contrails suggested maximal depolarization ratios were produced by ice crystals with radii as small as several tenths of a µm, explaining why they disappear in less than 20 seconds and so have different radioactive properties than cirrus clouds. In addition to producing vapor trails stretching thousands of miles across the sky, jet exhaust also seeds the atmosphere with cloud-forming aerosols - droplets of sulfuric acid and particles of soot. NASA's tests revealed that, at jet cruising altitudes, acid droplets account for at least 10 percent of the sulfur emissions. Transatlantic jets burn between 2.5 and 3 tons of fuel per hour. In 1988, before the Iraqi war, commercial aircraft consumed an estimated 70 percent of all jet fuel (with military and business craft accounting for another 24 percent). The world's aircraft currently produce about 3 percent the carbon dioxide (CO2) gases attributed to human activity. During takeoff, a jumbo jet can devour 2 million liters (528,344 gallons) of air per second. In the first five minutes of flight, a commercial airliner burns as much oxygen as 49,000 acres of forest produce in a day.
Note EU-Digest: The EU-Parliament should start looking far more seriously at this problem than they have done so far.
Labels: Airline Industry, Environment: climate change, Pollution and the environment
