Two environmentalists were arrested Monday after they sat on a ledge above an entrance to the National Oceanic and Atmospheric Administration building to protest what they said is the agency's suppression of information on global warming.

The pair scaled a ladder to the ledge 25 feet above the doors around 8 a.m. and unfurled a banner that read "Bush: Let NOAA tell the Truth." They sat on the narrow perch for about four hours, using suction cups with handles to anchor themselves to a window. Police eventually used a cherry picker from a nearby construction site to reach the protesters, who were lowered to the ground without a struggle.

Ted Glick, 56, and Paul Burman, 23, were both charged by Montgomery County police with disorderly conduct, reckless endangerment and trespassing.

The protest created a minor furor at the suburban Washington offices of NOAA, a relatively low-key federal agency that studies climate, weather and the oceans under the authority of the Department of Commerce.

About 30 federal and county police officers, backed by an incident command bus, converged on the building during the standoff. The westbound lanes of Route 410, a busy thoroughfare outside NOAA, were closed for about an hour as authorities assembled out front.

A handful of fellow protesters from the U.S. Climate Emergency Council and the Chesapeake Climate Action Network passed out fliers, waved signs at passing cars and chanted through a megaphone while Glick and Burman held on despite a brisk wind and cold temperatures. Both groups are based in nearby Takoma Park.

"People are seeing that the climate is changing," said Mike Tidwell, head of the Chesapeake Climate Action Network. "A grassroots movement is emerging from that."

The groups claim that the agency is purposely not releasing scientific evidence that supports arguments that global warming is contributing to an increase in intensity of weather, such as the 2005 spate of damaging hurricanes that included Hurricane Katrina.

A report in the scientific journal Nature last month claimed NOAA administrators blocked the release of a report that linked hurricane strength and frequency to global warming. In February, a NASA climate scientist said NOAA prevents researchers working on climate change from speaking freely about their work.

NOAA has denied both allegations and says its work is not politically motivated.