In Bill Bryson's Short History of Nearly Everything he makes the point that for most of its history the earth has been much colder than at present, including ti

In Bill Bryson's Short History of Nearly Everything he makes the point that for most of its history the earth has been much colder than at present, including times where the oceans have frozen. We are living in a temporary thaw. For all we know we are helping to perpetuate this thaw rather than slip back into another ice age. Maybe human generated global warming would have had to be implemented anyway to save the species. There's just so much we don't know.