Argument: Once geoengineering begins, there is no going back
Alan Robock. "20 reasons why geoengineering may be a bad idea". Bulletin of the Atomic Scientist. 2008: "11. There’s no going back. We don’t know how quickly scientists and engineers could shut down a geoengineering system—or stem its effects—in the event of excessive climate cooling from large volcanic eruptions or other causes. Once we put aerosols into the atmosphere, we cannot remove them."