"[Question] 5: How Much Is This Going to Cost? . . . Most . . . zero-carbon solutions are more expensive than their fossil-fuel counterparts. . . . These additional costs are what I call Green Premiums. . . . Green Premiums [can help us] decide which zero-carbon solutions we should deploy now [those with low or negative premiums] and where we should pursue breakthroughs because the clean alternatives aren't cheap enough."