SAN FRANCISCO - A federal judge ordered the Bush administration to issue two scientific reports on global warming, siding with environmentalists who sued the White House for failing to produce the documents.

U.S. District Court Judge Saundra Armstrong ruled Tuesday that the Bush administration had violated a 1990 law when it failed to meet deadlines for an updated U.S. climate change research plan and impact assessment.

Armstrong set a March 1 deadline for the administration to issue the research plan, which is meant to guide federal research on climate change. Federal law calls for an updated plan every three years, she said. The last one was issued in 2003.

The judge set a May 31 deadline to produce a national assessment containing the most recent scientific data on global warming and its projected effects on the country's environment, economy and public health. The government is required to complete a national assessment every four years, the judge ruled.

The last one was issued by the Clinton administration in 2000.

The administration had claimed that it had discretion over how and when it produced the reports — an argument the judge rejected Tuesday.

"The defendants are wrong," Armstrong wrote in the 38-page ruling. "Congress has conferred no discretion upon the defendants as to when they will issue revised Research Plans and National Assessments."

The plaintiffs — the Center for Biological Diversity, Friends of the Earth and Greenpeace — said the ruling was a rebuke to an administration that has systematically denied and suppressed information on global warming.

"It's a huge victory holding the administration accountable for its attempts to suppress science," said Kassie Siegel, an attorney for the Center for Biological Diversity, one of the plaintiffs that filed suit in Oakland federal court in November.