If we have fusion in 30 years instead of 60 years, we have colonization of the solar system happening in our lifetimes. We'd have the economic rationale for removing all military engagement in the middle east. We have 30*380 billion on petro cost savings here in the U.S: http://www.fuelfreedom.org/the-real-foreign-oil-problem/oil-... God knows how much CO2 we remove from the atmosphere. 100 billion sounds cheap to me.