EVEN without a "carbon tax" to make people pay a fee for greenhouse-gas emissions, investments in energy efficiency make good economic sense, experts say.
"It would be very easy to ... reduce emissions" below 1990 levels with strong leadership on the issue in Washington, says Nicholas Lenssen of the Worldwatch Institute.
The Union of Concerned Scientists says aggressive policies to promote energy efficiency could save the United States $5 trillion in electricity and fuel bills over the next 40 years. The program - using technologies that are on the market or in labs today - would cost $2.7 trillion, yielding a net savings of $2.3 trillion.
Studies by Congress's Office of Technology Assessment and the National Academy of Sciences also suggest that maintaining or cutting greenhouse-gas levels can be achieved using cost-effective technologies.
But if that is true, economists ask, why aren't businesses and consumers investing more?
William Cline, an economist with the Institute for International Economics, says one explanation is that "there is a certain amount of lethargy in any economic system" that blocks sweeping change. Publicity and promotion by government could help get the process moving, he suggests.
But W. David Montgomery, an economist with the consulting firm Charles River Associates, says the answer may be that these technologies aren't as cost-effective as the studies imply.
The money that a homeowner or a businessman gives up today to invest in an efficient appliance could be used for other purposes, perhaps with a higher rate of return, he notes.
Government is moving on several fronts to stimulate investment in energy efficiency.
Some 15 states have "demand-side management" programs in place, whereby electric utilities work to cut demand for power. The utilities give rebates to customers who install efficient light bulbs, and refrigerators.
In addition, the energy bill nearing completion in Congress is likely to:
* Set efficiency standards for lights, electric motors, commercial heating and air conditioning systems, and shower heads.
* Set efficiency standards for federal buildings, and encourage similar standards for the private sector.
* Reject a plan to tax utility rebates that reduce demand for power.
* Provide incentives for renewable energy.
Congress decided not to boost fuel-economy requirements for automobiles, a move sought by environmentalists but opposed by carmakers.