The Hurler On The Ditch

The top climate scientist at NASA says the Bush administration has tried to stop him from speaking out since he gave a lecture last month calling for prompt reductions in emissions of greenhouse gases linked to global warming.

The scientist, James E. Hansen, longtime director of the agency's Goddard Institute for Space Studies, said in an interview that officials at NASA headquarters had ordered the public affairs staff to review his coming lectures, papers, postings on the Goddard Web site and requests for interviews from journalists.

Dr. Hansen said he would ignore the restrictions. "They feel their job is to be this censor of information going out to the public," he said.

"Communicating with the public seems to be essential," he said, "because public concern is probably the only thing capable of overcoming the special interests that have obfuscated the topic."...

...Dr. Hansen, 63, a physicist who joined the space agency in 1967, directs efforts to simulate the global climate on computers at the Goddard Institute in Morningside Heights in Manhattan...

...He fell out of favor with the White House in 2004 after giving a speech at the University of Iowa before the presidential election, in which he complained that government climate scientists were being muzzled and said he planned to vote for Senator John Kerry.

But Dr. Hansen said that nothing in 30 years equaled the push made since early December to keep him from publicly discussing what he says are clear-cut dangers from further delay in curbing carbon dioxide...

Now that most scientists agree human activity is causing Earth to warm, the central debate has shifted to whether climate change is progressing so rapidly that, within decades, humans may be helpless to slow or reverse the trend.

This "tipping point" scenario has begun to consume many prominent researchers in the United States and abroad, because the answer could determine how drastically countries need to reduce their greenhouse gas emissions in the coming years. While scientists remain uncertain when such a point might occur, many say it is urgent that policymakers cut global carbon dioxide emissions in half over the next 50 years or risk the triggering of changes that would be irreversible...

...The debate has been intensifying because Earth is warming much faster than some researchers had predicted. James E. Hansen, who directs NASA's Goddard Institute of Space Studies, last week confirmed that 2005 was the warmest year on record, surpassing 1998. Earth's average temperature has risen nearly 1 degree Fahrenheit over the past 30 years, he noted, and another increase of about 4 degrees over the next century would "imply changes that constitute practically a different planet."

"It's not something you can adapt to," Hansen said in an interview. "We can't let it go on another 10 years like this. We've got to do something"...

...This tipping point debate has stirred controversy within the administration; Hansen said senior political appointees are trying to block him from sharing his views publicly.

When Hansen posted data on the Internet in the fall suggesting that 2005 could be the warmest year on record, NASA officials ordered Hansen to withdraw the information because he had not had it screened by the administration in advance, according to a Goddard scientist who spoke on the condition of anonymity. More recently, NASA officials tried to discourage a reporter from interviewing Hansen for this article and later insisted he could speak on the record only if an agency spokeswoman listened in on the conversation.

"They're trying to control what's getting out to the public," Hansen said, adding that many of his colleagues are afraid to talk about the issue. "They're not willing to say much, because they've been pressured and they're afraid they'll get into trouble."...