Sunshades and Global Warming

Could a cloud of two-foot wide sunshades 60,000 miles long save the Earth from a global warming emergency? Roger Angel (Steward Observatory, University of Arizona) has been studying the idea of making the spacecraft out of micron-thick glass weighing one gram per sunshade. That’s the weight of a butterfly for each unit, but we’re talking about trillions of them out at the L1 Lagrangian point, an almost fixed zone in relation to Earth whose mild orbital instability can be overcome by onboard intelligence. Total sunshade mass: 20 million tons.

here