COMING SOON: RUNAWAY MANMADE GLOBAL COOLING. Game-Changing Method Turns Carbon Dioxide Into Usable Energy With Incredible Efficiency. I remember Ralph Merkle postulating a cloud of solar powered nanobots that would float in the upper atmosphere and separate carbon dioxide into its component atoms. The combination of high-altitude soot blocking the sun (from the carbon) and the loss of greenhouse effect would produce a new ice age. He wasn’t terribly happy when I named it the “Merkle Cloud.”