"Temperatures are getting hotter, and they are getting hotter faster now than at any time in the past," said Michel Jarraud, deputy secretary general of the World Meteorological Organization.

Nine of the 10 warmest years since 1860 have occurred since 1990, the agency said, and temperatures are rising three times as fast as in the early 1900's.

As it has in the past, the organization attributed much of the warming to the greenhouse effect from burning fossil fuels.

"There are always skeptics on everything," said Ken Davidson, director of the agency's climate program, "but certainly the evidence we have today shows we do have global warming, and that most of this is due to human action."

In November, after four years of painful negotiations, delegates from 164 countries decided on the final details of a pioneering treaty aimed at fighting global warming.

While many large industrial countries said they were likely to ratify the agreement, President Bush rejected it, limiting its reach by sidelining the United States, the largest source of greenhouse gases.

If enacted, the treaty, called the Kyoto Protocol, would set the first binding restrictions on releases of carbon dioxide and other gases by industrial countries, which many scientists say have caused the warming trend.

But to gain legal force, the treaty must be ratified by at least 55 countries, including a group responsible for at least 55 percent of the heat- trapping emissions from industrial countries in 1990.

If that happens, the treaty will require that by 2012, participating industrial countries cut emissions of carbon dioxide and similar gases about 5 percent below their levels in 1990.

The agency said this year's global average surface temperature was expected to be 0.96 degrees Fahrenheit above the average for the past 40 years, which is 57 degrees.

The highest average, 58.1 degrees, was set in 1998, followed by this year, 1997, 1995 and 1990.

The high temperatures in 1997 and 1998 were partly the result of El Niño, in which warm water spreads over the surface of the central Pacific, but there was no such phenomenon this year.

Mr. Jarraud said the higher temperatures had led to an increase in storms, droughts and other unusual weather conditions, though he noted that "weather extremes are the result of complex interactions."