The Post spoiled a perfectly good editorial {''A Serious Mistake on CFC's,'' May 11} by supporting the Bush administration's phony line on global warming. The Post was absolutely correct in decrying the administration's foolhardiness and parsimony in refusing to assist the Third World in reducing its use of ozone layer-depleting CFC's. But The Post committed a grave error in endorsing the Bush administration's inaction on global warming.

President Bush has been roundly criticized by many of the world's governmental ministers, scientists and environmentalists for his extreme myopia when it comes to global warming. The Post published the White House ''Talking Points'' from the president's April Conference on Climate Change {news story, April 19}. This cynical guidance document for administration officials was the smoking gun proving that the White House is trying to manipulate the press and public on global warming. One ''point'' stressed: ''Not beneficial to discuss whether there is or is not warming, or how much or how little warming. In the eyes of the public we will lose this debate. A better approach is to raise the many uncertainties that need to be better understood on this issue.'' Another point read ''Don't let reporters position this conference as an attempt to delay serious discussions on this issue.''

Unfortunately, it appears that The Post has bought the administration's line on global warming. While environmentalists and scientists are advocating a cautious and reasonable program of energy efficiency to reduce carbon dioxide emissions by 20 percent by the year 2000, The Post seems to have endorsed the Bush Administration's ''just say no'' policy.

Environmentalists are not calling for ''hugely expensive and disruptive'' global warming reductions, as The Post maintains. Rather, our formula of 45 mile-per-gallon cars, energy efficient lightbulbs, appliances, heating and cooling systems and industrial equipment would actually save Americans $75 billion by the year 2000.

It is disturbing to see one of the largest and most respected newspapers in America being taken in, while most of the world's press saw the administration's lies for what they were. DANIEL BECKER Director, Global Warming and Energy Program Sierra Club Washington