New threat to Earth-based astronomy

If the sun warms the Earth too dangerously, the time may come to
draw the shade. The "shade" would be a layer of pollution
deliberately spewed into the atmosphere to help cool the
planet. This over-the-top idea comes from prominent scientists,
among them a Nobel laureate.

This weekend, NASA's Ames Research Center in Moffett Field,
Calif., hosts a closed-door, high-level workshop on the global
haze proposal and other "geoengineering" ideas for fending off
climate change.

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http://sfgate.com/cgi-bin/article.cgi?f=/n/a/2006/11/16/international/i112951S42.DTL