Global heat wave after 2009?

The Earth is headed for a record-setting heat wave after 2009, a team of U.K. climate experts said in the first such report based on observations from recent years.

Each year from 2010 through 2014 has at least a 50 percent chance of being warmer than 1998, the hottest on record, researchers led by Doug Smith of the Met Office, a government weather-forecasting agency based in Exeter, said Thursday in the journal Science.

The estimate is the first stemming from data collected since 1990 on ocean temperatures, heat-trapping gases and other factors. Other forecasters used information gathered from 1960 to 1990, the researchers said. By focusing on the next few years, rather than the longer time frame in earlier studies, the new report adds urgency to the challenge of reducing emissions that heat the atmosphere, Smith said.

"Global warming is a problem that needs some action sooner rather than later," he said in a telephone interview Tuesday.

Smith said he has used the new data to estimate annual global average temperatures through 2037. The results for years beyond 2014, which haven't been published, suggest that heat records will continue to be set after that.

Cooling in the Indian Ocean and the Western Pacific will forestall record annual temperatures for the next two years, Smith said. After that, global heat will resume an upward climb that has also been predicted by the United Nations' Intergovernmental Panel on Climate Change, he said.

The United Nations' World Meteorological Organization bolstered those estimates with a report saying that global surface temperatures were 1.89 degrees Celsius (3.4 degrees Fahrenheit) warmer than average in January and 1.37 degrees above the mean in April. Extreme heat is likely to become more frequent, the United Nations said.

The U.K. study shows how climate scientists can use upper-ocean temperatures to predict changes, said Radley Horton, a climatologist at the Columbia University Center for Climate Systems Research in New York. Water can store about 1,000 times more heat than the same volume of air, and Smith's study uses more upper-ocean data than other researchers have cited, he said.

"This can really contribute to improving 10-year-scale climate-model projections," Horton said in a telephone interview. "Decision-makers need these data to help set policy in the near term."

U.S. President George W. Bush rejected the Kyoto Protocol, which set carbon-emissions limits for 35 industrialized nations, saying it would hurt the economy and that fast-growing countries such as China and India weren't included.

Measures to control heat-trapping gases in the atmosphere are necessary to limit the rise in global temperatures, which has been associated with increased ice-sheet melting and hurricane activity, Smith said.

"Kyoto is a useful start to curbing emissions of greenhouse gases," he said.

The Kyoto agreement expires in 2012.

Only a rare event such as the eruption of a major volcano might keep warming at bay, at least temporarily, Smith said. For example, the 1991 eruption of Mt. Pinatubo, on Luzon in the Philippines, cooled global annual temperatures by about half a degree Celsius during the following two years, he said.

Pinatubo spewed out an enormous cloud of gas and ashes that spread around the earth in two weeks, blocking out some of the sun's rays.

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Contributing: Brian K. Sullivan in Boston

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