IT'S fashionable to scold the United States for refusing to set carbon dioxide (CO2) reduction targets. But that criticism goes wide of the mark.Countries trying to negotiate a global warming action agreement should keep their eye on the real target. The object of any such agreement is to mitigate the potential for such warming. It is not to aim at politically determined emission levels for one particular greenhouse gas. Several other gases help drive the atmospheric greenhouse effect. Ozone-destroying chlorofluorocarbons (CFCs) are substantial contributors. So too is methane of which agricultural activities, especially rice paddy farming, are prominent sources. The Bush administration argues that market-driven increases in energy use efficiency, the internationally agreed phase-out of CFCs, and other developments already underway will significantly reduce greenhouse gas emissions in this decade. It is wary of serious economic costs in trying to achieve arbitrarily set CO2 reductions. These could entail such steps as premature replacement of fossil-fuel power plants. It prefers an orderly phase-in of greenhouse gas reduction measures while scientists gain a clea rer view of any potential climate change. Even some of the critics seem, privately, to share this view. For example, European Community states jointly are committed to stabilize CO2 emissions in this decade and then to reduce them "substantially." Yet a European Commission study has concluded that market-driven changes already underway will probably stabilize the emissions by the year 2000 without any extra effort by the EC states. And what those states mean by subsequent "substantial" reductions remains undefined. They, too, seem reluctant to s et specific reduction targets that would cause such economic pain as reversing the community's plans to "substantially" increase road transport. There are economically sound actions that could reduce greenhouse gas emissions significantly. The US National Academy of Sciences notes, for example, that if US homeowners used the new efficient light bulbs, refrigerators, and water heaters and drove more fuel-efficient cars, they could cut US greenhouse gas emissions by 15 percent. Nevertheless, there also is need for concerted international action. The most serious criticism of the global warming negotiations is the unwillingness of most western nations to help their third world partners. For the latter, the new efficiencies are costly, as is the phase-out of CFCs. Rich signatories of the CFC treaty promised $240 million to help their poorer partners gain ozone-safe technology. So far, they have put up about $9 million. This is a sad precedent from which to negotiate a global warming mitigation agreement. The fundamental need is for the negotiating partners to agree on effective ways to help each other make the most of the economically sound measures already available.