By Ed Stoddard
SAN ANTONIO, Jan 18 (Reuters) - Joe D‘Aleo was a rare voice of dissent this week at the American Meteorological Society’s annual meeting in San Antonio.
D‘Aleo, executive director of the International Climate and Environmental Change Assessment Project, a group of scientists, doesn’t think greenhouse gas emissions are the major cause of global warming and climate change.
Researchers who hold such contrary views do not appreciate being lumped together with flat-Earthers. They are legitimate scientists who question the mainstream, but they are a distinct minority.
"Greenhouse warming is real, but I think it is a relatively minor player," D‘Aleo said.
He claims other factors like solar activity and other natural causes are probably playing a greater role in rising temperatures -- a position that gets a mostly chilly reception from this crowd.
Several scientists and writers interviewed at the society’s conference, which ends on Thursday, stressed that most researchers believe there is little scientific debate about the causes of global warming.
That does not mean there is a consensus.
"There’s not a consensus on anything. There are people who say the Earth is not round, there are people who say that the Earth is 6,000 years old," said Richard Anthes of the Colorado- based University Corporation for Atmospheric Research.
"The vast majority of credible scientists from thousands of peer-reviewed papers agree that the strong balance of evidence is that the Earth is warming and the major cause of that is anthropogenic (human-caused) emissions."
Mainstream scientific opinion holds that emissions from fossil fuels are trapping heat in the atmosphere -- the so-called "greenhouse effect." Such emissions come from cars, factories and power plants.
U.S. President George W. Bush’s annual State of the Union speech to Congress next week is likely to tweak climate change policy, but stop short of the mandatory emissions caps that many greens would like to see, sources have said.
"I think there is largely agreement on the fact that over the last 30 years, that much of that warming has been attributed to human activities, in other words, greenhouse gas emissions," said Tony Socci, a American Meteorological Society senior science fellow.
He said those who denied the connection were either "badly informed as to the scientific center or consensus, or in some cases perhaps (they are) just not wanting to be informed."
Greenhouse gas skeptics would retort that the meteorological mainstream has not gotten a handle on the science behind solar activity and other natural cyclical causes and fed it into the models.
D‘Aleo said there was an element of peer pressure to toe the party line.
"A lot of them are not willing to speak up because it might endanger grants and jobs," he said.
For others, the evidence is overwhelming.
Temperatures rose by about 1.1 Fahrenheit (0.6 Celsius) during the 20th century and may rise another 1.4 to 5.8 Celsius from 1990 to 2100, a rate unprecedented in at least 10,000 years, according to the United Nations Intergovernmental Panel on Climate Change.
"I think there’s virtually no doubt that humans are a major player in warming the globe," said Robert Henson, author of the recently published "The Rough Guide to Climate Change."
"There are still people out there who will contradict that, but they are not part of the scientific mainstream," he said.
The dissenters would say that is the point: portraying them as the wild-eyed fringe or lackeys of oil companies makes even legitimate questioning seem less credible.