President Clinton's insistence that the Kyoto Protocol to combat global warming won't damage the U.S. economy has been undercut by one of his own federal agencies. In a new report, the Energy Information Administration (EIA), a unit of the Dept. of Energy, estimates that implementation of the protocol would boost the average energy costs of U.S. households by between $335 and $1,470 annually by 2010. That's far higher than the $70 to $100 estimate of the White House's Council of Economic Advisors. EIA also projects a drop in the gross national product of $61 billion to $397 billion compared with the Administration's estimate of $1 billion to $5 billion. The EIA study, being widely circulated by industry opponents of the protocol, comes just as negotiators are preparing for the fourth Conference of the Parties on a climate-change treaty in Buenos Aires Nov. 2-13. This newest round of negotiations is aimed at reaching consensus on implementing key details of the protocol. The most sticky issue: the U.S.'s demand that developing countries should be subject to the same binding reductions in greenhouse-gas emissions as developed nations.