Its funny that there needs to be a what some would call a "pollution" balance, similar to what tug mentioned above. Makes the what 50 or more volcano's and the nasty stuff they spew out very important for the earths atmospheric health. So yeah looks like if they get rid of Co2, then earth quakes will be the norm. So in the end the well designed earth systems can cure anything man does as long as it isn't some huge concerted effort, like setting hundreds of nukes off everyday, and filling the sky's with thousands of fuel guzzling jet engine heating machines like is done now, just normal everyday average peeon life stuff has zero effect.
