The United States has come in for harsh criticism at a United Nations event marking the entry into force of the Kyoto climate change treaty.  The job of defending U.S. global warming policies fell to a lone Republican senator.

It was a day of tough words aimed at the United States for its rejection of the Kyoto protocol. The theme, "One Day After Kyoto", was a play on a recent hit movie on the possible catastrophic effects of global warming, entitled The Day After.

The event, sponsored by U.S. businessman Ted Turner's United Nations Foundation, was held at U.N. headquarters.  Speakers included scientists, diplomats, businessmen and lawmakers.

Britain's U.N. Ambassador Emyr Jones-Parry told the group the United States, as the biggest producer of greenhouse gasses, should pay more attention to global warming.

"The U.S., with four percent of the world population, is responsible for 20 percent of global emissions," he said.  "It consumes almost a quarter of the world's energy, more than China, Russia and Japan combined. The average American citizen produces 21 tons of carbon per year, twice that of a British or Japanese citizen. It is important that climate change rise up the U.S. agenda."

There was no one representing the Bush administration at the event, but Republican Senator Chuck Hagel defended U.S. policy. Senator Hagel was co-sponsor by a 1997 resolution urging then President Bill Clinton not to sign the Kyoto treaty unless it applied to all countries, or if it would harm the U.S. economy. The resolution was adopted unanimously.

Senator Hagel told the U.N. audience the question is not whether to take action to combat global warming, but what action to take. He said a better standard is needed for measuring greenhouse gas emissions.

"The scientific community is not uniform in its assessments of the causes or solutions for dealing with climate change," said Mr. Hagel.  "But I believe that greenhouse gas intensity, or the amount of carbon emitted relative to economic output, is the best measurement for dealing with climate change now."

Senator Hagel said he had introduced three pieces of legislation this week using greenhouse gas intensity as the baseline for U.S. climate policy.

The Nebraska Republican said he had discussed with British Prime Minister Tony Blair a possible compromise that would address some U.S. concerns about the Kyoto treaty.

"I discussed climate change with Prime Minister Blair in London and I know he supports Kyoto," Mr. Hagel said.  "But I do believe he also understands the limitations of Kyoto, the essential role of technology in addressing climate change, and the need for collective action if we are to be successful for global climate change policy."

Senator Hagel pointed out that Prime Minister Blair had told the Davos economic forum last month that a fresh injection of political will was needed to achieve a consensus on global warming strategy. He said, "the United States must be part of that strategy."

The senator said he has discussed global warming policy with Secretary of States Condoleezza Rice and others in the administration and in Congress, and suggested compromise would be discusses during upcoming efforts to heal the rift between the United States and Europe.