Page 2 of 2   <      

In e-mails, science of warming is hot debate

For a few, however, the stolen files were confirmation that the climate establishment was trying to keep them out of the debate.

These include the familiar kind of climate skeptics, those who think that the climate isn't changing or that it isn't a crisis. But they also include a handful of researchers who think climate change is happening, but -- for various reasons -- are skeptical that mainstream science fully understands the phenomenon.

"To me, it's unambiguous . . . humans are altering the climate system," said Roger Pielke Sr., a research scientist at the University of Colorado. "It's just that, it's much more than CO2."

Pielke said his research shows that, in addition to carbon dioxide and other factors, Earth's warming is affected by how people alter the land. When a forest becomes a farm, or a farm becomes a suburb, that changes the amount of heat and moisture coming off the ground, he said.

But Pielke said he has seen some papers rejected and has felt so marginalized that he quit a U.S. panel summing up climate change a few years ago. One of the stolen e-mails seems to confirm the idea that he was being excluded: In 2005, Jones wrote to colleagues about some of Pielke's complaints, "Maybe you'll be able to ignore them?"

"These individuals, who are very sincere in their beliefs, have presumed that that gives them permission to exclude viewpoints that are different from their own," Pielke said.

Mainstream climate scientists say they have kept an open mind but have rejected papers that lack proper evidence. In Pielke's case, "the literature doesn't show" his ideas about the importance of land use are correct, said Tom Karl, head of the NOAA's National Climatic Data Center.

Top climate scientists say that in recent years most of the new, worthy research has only made the threat of climate change seem bigger and faster.

But the current debate over what's happening to global temperatures shows the noisy, confusing disagreement of scientists trying to make nature make sense.

These are the facts: After an increase in 1998, the world has been historically warm, but its average temperatures have not climbed steadily. Does that mean climate change has stopped?

Many mainstream scientists say no: This is just a tic of nature, as cycles of currents in the Pacific Ocean and a decrease in heat coming off the sun have temporarily dampened warming. Some researchers, though, have said the models -- and, by extension, the human researchers that built them -- could be missing something about how the climate works. That point was made in one stolen e-mail, in which climate researcher Kevin Trenberth wrote it was a "travesty" that models could not explain why the Earth hadn't warmed more.

"We're simply not tracking where the heat is going," said Trenberth, who heads the Climate Analysis Section at the National Center for Atmospheric Research in Boulder.

The diversity of opinion on this topic, however, wasn't evident late last month, when a group of 26 climate researchers issued a report called "The Copenhagen Diagnosis," summarizing scientific advances since the last major U.N. climate report in 2007.

"Has global warming recently slowed down or paused?" the report said. "No."


<       2

© 2009 The Washington Post Company