Because of the many ominous predictions for the climate, policy makers from both national governments and international organizations are demanding policy adoptions in the form of carbon taxes, mandated efficiency measures, and subsidies for non-carbon dioxide-emitting technologies to roll back greenhouse gas emissions to their 1990 levels.[2] While there is disagreement among climatologists regarding the significance of the "greenhouse" effect, there seems to be more agreement among other investigators that "cutting back" significantly on greenhouse gas emissions would have more serious negative worldwide impacts, with large Gross Domestic Product reductions, resulting in lower living standards in the long run.[3] Looking back to the recent past, it is now all but forgotten that some outspoken climatologists in the late 1970s predicted a completely opposite scenario, a return to an ice age with cataclysmic impacts, which also demanded immediate attention.