 Detail of Chris Jordan’s Jet Trails Depicts 11,000 jet trails, equal to the number of commercial flights in the US every eight hours. |
This research is old news, and complicates the whole Global Warming debate even further. Air pollution might be behind observations that the amount of solar radiation reaching the Earth’s surface has gone down drastically over five decades of observations:
“There was a staggering 22% drop in the sunlight, and that really amazed me.” Intrigued, [Dr. Gerry Stanhill] searched records from all around the world, and found the same story almost everywhere he looked.
Sunlight was falling by 10% over the USA, nearly 30% in parts of the former Soviet Union, and even by 16% in parts of the British Isles.
Although the effect varied greatly from place to place, overall the decline amounted to one to two per cent globally every decade between the 1950s and the 1990s. (source)
I really don’t appreciate the overly-dramatic score and alarmist tone of the BBC Documentary Global Dimming, and Real Climate has some valid criticisms of the science (such as birds drinking from evaporation pans), but it does explain the science behind global dimming phenomena fairly well:
[googlevideo=http://video.google.com/googleplayer.swf?docId=39520879762623193&hl=en]
One of the most shocking bits of data covered in this documentary comes at 31:51 minutes into the program, and deals with a one-degree Celsius temperature spike that occurred in America in the three days after 9/ll, when there were no jets in the sky, and therefore no jet contrails to reflect sunlight back to space. This leads to the possibility that as we improve our air quality, we also increase the effects of global warming.
Just another variable in the immensely-complex system that is the Earth’s climate to be considered with methane release in melting Siberia, cosmic rays, cloud coverage, and myriad other complications.