The World Meteorological Organization says the brutal heat waves that killed thousands of people in Europe in 2003 and that choked Russia earlier this year will appear like an average summer in the future as the Earth continues to warm.
The director of the WMO's World Climate Research Center, says the trend of the last few decades indicate that extreme heat will become more frequent and intense in the future.
Ghassam Asrar told reporters at the 193-nation U.N. climate conference Tuesday the pattern of Atlantic storms also is changing. The number of mild Category 1 storms is declining, but the frequency of powerful Category 4 and 5 hurricanes is increasing.
He cautions that more studies are needed to draw global conclusions.
THIS IS A BREAKING NEWS UPDATE. Check back soon for further information. AP's earlier story is below.
CANCUN, Mexico (AP) -- Mexican President Felipe Calderon says he can understand why U.S. voters in an economic crisis turned to the opposition party, but he hopes the Republicans will eventually accept the need to protect the planet's climate for "new generations."
"I hope they can realize sooner or later how important it is for the future," Calderon said Monday.
At the same time, in an implicit criticism of China, the Mexican leader also spoke of poorer nations taking a "radical" position against any legally binding commitments to rein in their emissions of carbon dioxide and other industrial, transport and agricultural gases blamed for global warming, something he said Mexico is willing to do.
Calderon met with The Associated Press after Monday's opening of the annual negotiating conference of parties to the 193-nation U.N. climate treaty.
Mexican warships patrolled off the beaches as Calderon's government, in a bloody struggle with drug cartels, threw a thick security cordon around the sprawling hotel zone in this Caribbean resort for the two weeks of talks.
The diplomatic effort to impose stronger controls on global warming gases has been stymied in recent years by friction between the two biggest emitters, China and the United States.
The U.S. has long refused to join the rest of the industrialized world in the Kyoto Protocol, the 1997 climate treaty adjunct that mandated modest emissions reductions by richer nations. The Americans complained it would hurt their economy and it exempted such emerging economies as China and India.
The Chinese, for their part, have resisted pressure from the U.S. and others in recent years to take on binding commitments not to reduce, but to limit the growth in their emissions, saying they were still too poor to risk slowing down their economy.
The election of a Republican majority in the House of Representatives in the Nov. 2 elections has made it all but impossible for at least two years that any U.S. legislation would pass to cap carbon emissions, essential for drawing other nations into a new, more stringent pact to succeed Kyoto, which expires in 2012.
Many Republicans dismiss scientific evidence of global warming, and fought against Democrat-sponsored energy legislation the past two years.
Asked about the impact of the U.S. November election on global climate efforts, Calderon said it was difficult to comment on a neighbor's internal affairs, but "the economic crisis in the United States was a setback to the quality of life for millions and millions of Americans, and it is a very important factor in the opinion of the people. I can understand that."
But, in an echo of President Barack Obama, Calderon, a former Mexican energy secretary, said political leaders must explain better to their people that a climate-friendly transformation from polluting fossil fuels to renewable energy would actually boost their economies.
"We need to persuade people that we are going to help them to recover the economy, to recover their jobs and at the same time we need to take action in favor of new generations, and probably they can find their new jobs in this new green economy," he said.
Asked whether he believed bigger developing nations, such as Mexico, would ever join with industrial nations in a new binding treaty on climate, Calderon said Mexico "has the will" to do it -- on condition it's done on the basis of "common but differentiated responsibilities," climate treaty language taken to signify that poorer countries would not be required to actually roll back emissions, but only to institute other controls.
But he cited "other countries, especially big emitters, that express the radical position that they will not accept by any means any kind of binding commitments."
Is China among them? "It could be China, and other countries," he replied.
But he quickly added that "in my experience, the Chinese government is starting to take action in terms of these issues, particularly in terms of the energy efficiency program, very aggressive."
Calderon, Mexico's president for the past four years, was animated and engaged in a 40-minute interview on the climate crisis. He's expected to take a personal hand next week in trying to resolve disputes over secondary treaty issues debated here, while the world waits for an end to the gridlock on a new global accord to ward off the worst of climate change.
He lamented that the "big players" are stalling progress for everybody else, and said others "need to start already on what is possible."
As an example, he cited his government's soon-to-be-announced plan to replace traditional incandescent light bulbs with new energy-saving bulbs.
Associated Press writer Mark Stevenson contributed to this report from Cancun.