The Hall Weather Machine is a thin global cloud consisting of small transparent balloons that can be thought of as a programmable and reversible greenhouse gas because it shades or reflects the amount of sunlight that hits the upper stratosphere. These balloons are each between a millimeter and a centimeter in diameter, made of a few-nanometer thick diamondoid membrane. Each balloon is filled with hydrogen to enable it to float at an altitude of 60,000 to 100,000 feet, high above the clouds. It is bisected by an adjustable sheet, and also includes solar cells, a small computer, a GPS receiver to keep track of its location, and an actuator to occasionally (and relatively slowly) move the bisecting membrane between vertical and horizontal orientations. Just like with a regular high-altitude balloon, the heavier control and energy storage systems would be on the bottom of the balloon to automatically set the vertical axis without requiring any energy. The balloon would also have a water vapor/hydrogen generator system for altitude control, giving it the same directional navigation properties that an ordinary hot-air balloon has when it changes altitudes to take advantage of different wind directions at different altitudes.
By controlling a tenth of one percent of solar radiation is enough to force global climate in any direction we want. One percent is enough to change regional climate, and ten percent is enough for serious weather control.
The surface are of the earth is 510 trillion square meters.
So getting to 0.1% coverage is 510 billion square meters.
There is mylar that is 2 microns thick and weighs about 2.4 grams per square meter. Office Paper is usually 80 grams per square meter.
So if you could achieve large scale production (equal to 1% of total US plastic film production in 2012) of 1 gram per square meter balloon sheeting with a diamond surface treatment and the other parts of the system there would be 73,000 tons of weather machine produced. This would cover 73 billion square meters. In about 8 years, one would be able to produce a 1% coverage Hall Weather Machine.
The production system would be a more advanced version of bubble wrap production. Each bubble would be functionalized and perhaps laser cut into separate balloons. Rapid printable electronics would probably be the best way to get the solar cell and GPS components into the bubble/balloon. The printable electronics would need to be scanned onto the surface of the sheet, before the top layer is attached.