Friday, April 27, 2007

Space Umbrella & Global Warming

A very wow idea…and cool in more ways than one…

The fact that this might be needed, and can be built, is all the case needed for a much greater budget for NASA.

UN panel proposes giant parasol in space
Dennis Buecker, The Canadian Press
Published: Wednesday, April 25, 2007

If all else fails in the battle to curb global warming, there's always the big umbrella in space.

Governments should consider proposals to put a huge barrier in space to block sunlight if conventional efforts to curb rising temperatures don't succeed, says a draft report by the UN Intergovernmental Panel on Climate Change.

Scientists believe that such "geo-engineering techniques," however far-fetched they sound, could be used to buy time if worst-case ecological predictions are realized.

A sun-blocking disk would cover an area of 106 square kilometres, weigh 3,000 tonnes and would spin continually. It would be built over time by a space shuttle, says the draft report. Construction would require one shuttle flight annually for 100 years.

Another proposal, which some liken to an artificial volcano, calls for controlled scattering of tiny sulphur particles in the atmosphere, to reduce sunlight reaching the planet.

Nobel Prize-winning scientist Paul Krutzen has advocated this as the safest of the unconventional techniques that are being considered, since natural volcanic eruptions are known to produce a cooling effect that is reversible. "These schemes do not affect the expected escalation in global carbon dioxide levels, but could reduce or eliminate the associated warming," says the draft study.