Releasing large quantities of sulfur dioxide into the atmosphere is exactly what volcanoes do in large eruptions. So, like I said before:
Quote Originally Posted by drone View Post
And all this work and fuss will mean nothing the next time some random volcano in the Pacific Rim blows it's top and spews enough ash and sulfur dioxide into the atmosphere to cool the planet down by a couple of degrees.
Of course, the downside of sulfur dioxide in the atmosphere is acid rain, but beggars can't be choosy.