wrote in message
ups.com...

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 one will be many orders of magnitude more cost effective. If
memory serves the average life expectancy of such dust in the atmosphere
is around three years. This should enable fairly responsive regulation
of dust levels.

Perhaps a dozen 747s continuously ferrying dust to altitude might be
sufficient, (highly dependent on assumptions, particularly average
particle size). A cross the board jet fuel dust additive might be more
easily made to happen, it might only be a few percent of such fuel by
mass. Fly back artillery systems, high mountains and towers, thermals
from power stations, jet streams, etcetera, might also bring the cost
down dramatically. The type of dust might also be selected for specific
wave lengths - reduced UV might greatly reduce cancer rates.

A nuclear winter is the quick fix to global warming, and it would only
take one nuclear power to get desperate.

Lets say global warming does get bad and result in global depression,
this would quite likely result in at least a little nuclear war as
people naturally start fighting over fewer resources. So global warming
will be "naturally" counter acted. :-)

Pete.