Giant Parasol Seen as Earth Sunshade

A Swiss scientist has suggested cooling down the Earth by unfurling a sunshade half the size of the United States in space.

Walter Seifritz says in the latest edition of the science magazine Nature that his solution to the “greenhouse effect,” the warming of the atmosphere through pollutants retaining the sun’s heat, is “a remote but feasible possibility.”

A satellite carrying aluminum mirrors would be positioned at a point in space 900,000 miles from Earth, where it would cast a permanent shadow on the planet.

Seifritz calculates that 45 million tons of material would have to be rocketed up over a period of 20 years.