A Cambridge astronomer has claimed that global warming may do for ground-based astronomy by 2050 - due to a significant increase in cloud cover provoked by expanding aircraft condesation trails, New Scientist reports.
Cambridge Uni star gazer Gerry Gilmore chaired a study to examine the effect of global warming on "contrails" and how they would affect the operation of the upcoming Overwhelmingly Large Telescope (OWL) project.
The conclusion is simple: "Contrails increase global warming, and global warming helps larger contrails form," Gilmore explains. Indeed, the study demonstrated that the problem is much greater than previously thought, showing that "ground-based telescopes will be worthless by 2050."
Gilmore concludes: "We can only go to the least affected places and try to make governments pass laws to protect these sites. But the future of cheap aeroplane transport and climate change is out of our hands."
None of this will surprise the American Geophysical Union, which was reporting back in 1999 on a NASA Langley Research Centre report stating: "By the year 2050, increased flights by jet airplanes will impact global climate through the greater number of contrails they will produce."
Even back then, the research noted: "Large, linear contrails can be observed in satellite imagery. Although their total global coverage has not yet been determined, it is computed from traffic and weather data to amount to 0.1 percent. In parts of Europe and eastern North America with the heaviest air traffic, however, contrails currently cover up to 3.8 percent and 5.5 percent of the sky, respectively."
The NASA data suggested that "by 2050, average contrail coverage over Europe will be four times higher than at present, or about 4.6 per cent. In the United States, the increase will be 2.6 times current levels, or 3.7 per cent coverage; and in Asia, the increase will be ten times current levels, or 1.2 per cent". ®
There are plenty of other contrail/astronomy-related links available at Copenhagen University Observatory researcher Holger Pedersen's site (last updated 2003).