This is not new information. Well, perhaps it is for the LA Slimes. But I seem to recall reading something along these very same lines over a decade ago.
Mount St. Helens did the same thing, as did Saddam Hussein when he torched the oil wells in Kuwait when he exited. Both incidences caused the temperature to drop 2-3 degrees. And we are supposed to be alarmed by a couple 10ths of a degree over the course of a century because of AGW?