WASHINGTON – A former White House official accused of improperly editing reports on global warming defended his editing changes yesterday, saying they reflected views in a 2001 report by the National Academy of Sciences.

House Democrats said the 181 changes made in three climate reports reflected a consistent attempt to emphasize the uncertainties surrounding the science of climate change and undercut the broad conclusions that man-made emissions are warming the earth.

Philip Cooney, former chief of staff at the White House Council on Environmental Quality, acknowledged at a House hearing that some of the changes he made were “to align these communications with the administration’s stated policy” on climate change.

The extent of Cooney’s editing of government climate reports first surfaced in 2005. Shortly thereafter, Cooney, a former oil industry lobbyist, left the White House to work at Exxon Mobil Corp.

“My concern is that there was a concerted White House effort to inject uncertainty into the climate debate,” said Rep. Henry Waxman, D-Calif., chairman of the House Government Reform Committee.

Cooney’s appearance before Waxman’s committee yesterday was the first time he has spoken publicly, or was extensively questioned, about the issue.

Cooney said that many of the changes he made to the reports – such as uncertainty about the regional impact of climate change and limits on climate modeling – reflected findings of a 2001 National Academy of Sciences report on climate.

Waxman’s committee also heard from James Hansen, director of NASA’s Goddard Institute for Space Studies and one of the country’s leading climate scientists, who said the White House repeatedly tried to control what government scientists say to the public and media about climate change.

“Interference with communications of science to the public has been greater during the current administration than at any time in my career,” said Hansen, who was one of the first to raise concerns about climate change in the 1980s.