Time to start building space elevator or die

Which do you think would be most cost efficient.
1) Creating a reflective dust cloud round the Earth
2) Placing some kind of umbrella in orbit round the Earth
3) Placing a much smaller umbrella at the stable point between the
Earth and Sun.

Option 1 would probably continuously need topping up.

Option 2 would need to surround the whole Earth to give an effective
shield with only that on the Sun facing side working at one time.
Rather a hazzard to space flight as well.

Option 3 would need more fuel to place in position, but would be much
smaller thus might be more efficient.


Rand Simberg wrote:
On Sun, 26 Jun 2005 22:09:11 GMT, in a place far, far away,
lid (John Savard) made the phosphor on
my monitor glow in such a way as to indicate that:


Why, yes, there are. We _can_ tread more gently on the Earth without
attempting to curtail human material well-being to an unrealistic
extent. There are other ways to produce energy besides the use of fossil
fuels.

Yes, and as the cost of fossil fuels rises, we will continue to shift
over to them more and more.