TAKING THE NEXT STEP IN GEOENGINEERING.

The basic idea behind stratospheric injection is that spraying particles high above the Earth could help reflect more heat back into space, offsetting rising temperatures. It would mimic a natural phenomenon that occurs when large volcanic eruptions blast sulfur dioxide into the atmosphere, which nudges down global temperatures in the months that follow.

For the proposed experiment, Keith and fellow Harvard professor Frank Keutsch plan to launch high-altitude balloons that would spray small amounts of materials such as sulfur dioxide, alumina, or calcium carbonate into the stratosphere. They would then employ sensors to measure the reflectivity of the particles, the degree to which they disperse, and how they interact with other compounds. Initial test flights could occur as early as next year.

Just to hedge our bets, maybe we should also be thinking about responses to an Ice Age. And maybe working on frost-tolerant, short-growing-season crops.