[Carlhole]

Al Fin

Today, we take another look at Josh Hall's climate machine, a system which reaches into the outer atmosphere in order to control how much sunlight can get through. Brian Wang has more:

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.

Of course, if controlling one tenth of one percent of incoming sunlight can force global climate "in any direction we want", what about 20% or 50%? (Can you say "Instant Ice Age?") Of course, we humans really do not know enough about global climate to be qualified to adjust solar radiation wisely.

I didn't think the GPS part would work. You would have to have trillions of these things.

[dissident]

Instead of stopping CO2 pollution some want to hide it by various fantastical schemes to block sunlight. The oceans will still be acidifying and thereby reducing their potential as CO2 sinks through phytoplankton die off. Deforestation and land degradation will still continue leading to reduction in the land CO2 sink capacity. So we will have a build up of CO2 in the atmosphere that will wait when these technological "solutions" fail. The timescale for CO2 to clear out of the system will be tens of thousands of years and depending on how much we produce it may end up taking hundreds of thousands of years. Technotopia won't last this long.

We need real solutions and not crack pipe dreams.