The threat of serious, unpredictable, and probably irreversible changes in the earth's climate has moved from conjecture to suspicion to near-certainty (1). Denial is now confined to the uninformed (2). Yet the threat's cause continues to be widely misunderstood even by many experts on its mechanisms.Global warming is not a natural result of normal , optimal economic activ ity. Rather, it is an artifact of the economically inefficient use of resources, especially energy. Advanced technologies for resource efficiency, and proven ways to implement them, can now support present or greatly expanded worldwide economic activity while stabilizing global climate-and saving money. New resource-saving techniques--chiefly in energy, farming, and forestry-generally work better and cost less than present methods that destabilize the earth 's climate .In short, even based on energy-efficiency assessments by such organiza tions as the Electric Power Research Institute (the utility industry's think tank) and leading US national laboratories , most of the best ways known today to abate climatic change ("stabilize" the climate) are