One belch might be pushing it a bit. Even IF fossil fuels are not the main cause of global warming I think using them is not a good Idea. They are a major source of pollution and cause other ecological devastation which is provable.
Opposite of many people who say we dont know, I think the fact that we dont know is most of the tim a good reason not to use technology. Wait until we do know. Of course that takes out a lot of the profit and the guys making the big profit could care less how the general public is harmed by unintended effects.
I find the Volcanoe argument interesting because the government and oil companies could have used it to blame for global warming. Yet they did not. WHY? My guess is that the myth that we have "tamed" nature with technology is more important to justify using unproven technology. That is of course just a guess.