Efforts to hold major greenhouse gas emitters accountable for the harms caused by global climate change have been consistently frustrated at the procedural stages of litigation in U.S. federal courts. This Article explores using a combination of class action mechanisms to engage with these threshold barriers and hold carbon-major corporations responsible for climate impacts. Specifically, it proposes using issue certification under Federal Rule of Civil Procedure 23(c)(4) against a defendant class of carbon-major polluters to overcome the causation question that has obstructed federal courts’ engagement with the merits of climate change litigation.