A NASA scientist said Tuesday that the Bush administration is trying to hush up scientific evidence of global warming and keep the public uninformed.

James E. Hansen told an audience at the University of Iowa that the government is screening information flowing from scientists to the public more than he has ever seen in 30 years.

Hansen, the director of the NASA Goddard Institute for Space Studies in New York, says the administration only wants to hear scientific evidence that fits its view that global warming is not a threat.

Wide scientific agreement

Hansen says there's wide agreement in the scientific community that greenhouse gases such as carbon dioxide created by burning fossil fuels are trapping heat and creating global warming.

He has twice briefed a task force on global warming headed by Vice President Dick Cheney.

But he says reports on the problem are routinely edited to make it seem less serious.

White House science adviser John H. Marburger denies that the administration is refusing to recognize the seriousness of global warming.

He says President George Bush spoke on the dangers of greenhouse gases as long ago as 2001.