In an effort to clean up acid rain and smog, New York Gov. George Pataki (R) today will order power plants in the state to make sharp reductions in their emissions of sulfur dioxide and nitrogen oxides. Enviros were happy about the news, as were power companies with proposals to build new natural-gas plants, which are relatively expensive to construct but which produce far less pollution than old coal-burning plants. Under the new rules, gas-fired plants will be able to better compete with coal-fired plants because the coal plants will have to invest in expensive filtering systems. The New York plan could add momentum to efforts in Congress to curb power-plant emissions nationwide, said John P. Cahill, New York’s commissioner of environmental conservation. Meanwhile, New York Attorney General Eliot Spitzer (D) yesterday threatened to sue the state’s power plants for polluting the air.