Sen. Barbara Boxer (D-Calif.), a co-sponsor of the bill, has called it "the world's most far-reaching program to fight global warming." It is indeed policy on a grand scale. It would slow American economic growth by trillions of dollars over the next half-century. But in terms of temperature, the result will be negligible if China and India don't also commit to reducing their emissions, and it will be only slightly more significant if they do. By itself, Lieberman-Warner would postpone the temperature increase projected for 2050 by about two years. Politicians favor the cap-and-trade system because it is an indirect tax