Humans are main cause of warming, scientist says

Testifying before a Senate commerce subcommittee on global climate change, he cited data from weather stations and ships indicating that the surface of the earth is hotter by about seven-tenths of 1 degree Fahrenheit since the early '70s.

Administration officials stressed the $5 billion spent yearly on US climate programs, mostly for research. David Conover, a principal deputy assistant energy secretary, said President Bush would lead on the issue, though ''the scientific and technology challenges are considerable."

James Mahoney, assistant commerce secretary for oceans and atmosphere, said, ''We know that the surface of the earth is warmer and that an increase in greenhouse gases caused by humans is contributing to the problem." He did not go further than that.

Just three senators -- David Vitter, Republican of Louisiana; Frank Lautenberg, Democrat of New Jersey; and Ted Stevens, Republican of Alaska -- were at the hearing. All three shared concerns about coastlines disappearing.

Cicerone also bolstered a 2004 Pentagon report that two private consultants prepared on potential impacts of a severe change in the world's climate. It was met with skepticism and disbelief, even by the Pentagon official who commissioned it.

Among consequences sketched out were surging seas breaking down levees in the Netherlands in 2007, making the Hague ''unlivable," and Europe's climate becoming ''more like Siberia's" by 2020.

''It was well done," Cicerone said of the report. ''I didn't think it was fictional."

Bush said earlier this month that he recognizes that human activity contributes to a warmer earth. But he still rejects the Kyoto treaty on global warming that all other G-8 nations signed, because developing nations weren't included in it.

His administration has argued gainst mandatory climate-related emissions caps, contending that its voluntary program is countering the growth of emissions, but not reducing the tons annually being released into the atmosphere.