If you ask Bob Zybach, he will tell you there is a global warming problem, but the forest ecologist figures it is nothing more than hot air from scientists and politicians gathered in Copenhagen at the United Nations' global warming conference.

If you ask Bob Zybach, he will tell you there is a global warming problem.

But the forest ecologist figures it is nothing more than hot air from scientists and politicians gathered in Copenhagen at the United Nations' global warming conference.

"The bottom line is that the science on global warming is unsettled — there is no consensus on the science," he said. "There is simply a hypothesis at this point. How about some proof?"

He took issue with a Dec. 3 article in the Mail Tribune that reported that the Society of Conservation Biology sent a letter to the prime minister of Denmark recommending 11 climate change policy principles be adopted at the conference.

Forest ecologist Dominick DellaSala of Ashland wrote two of those principles for the society comprised of more than 10,000 conservation scientists from 140 countries.

DellaSala, president and chief scientist of the National Center for Conservation Science & Policy in Ashland, recommended that policies be adopted to reduce greenhouse gas emissions to those approaching historic levels and protect the world's primary and older forests for their ability to capture and store large quantities of carbon for centuries.

The society believes there is ample proof of human-caused climate change, from the growing greenhouse gases in the atmosphere to rising temperatures worldwide.

Zybach disagrees. He was among 141 scientists from around the world, including former Oregon state climatologist George Taylor, who fired off a letter on Dec. 9 to Ban Ki Moon, secretary-general of United Nations, stressing they believe there are more questions than answers about global warming.

" ... there is no sound reason to impose expensive and restrictive public policy decisions on the peoples of the Earth without first providing convincing evidence that human activities are causing dangerous climate change beyond that resulting from natural causes," the letter stated.

"Before any precipitate action is taken, we must have solid observational data demonstrating that recent changes in climate differ substantially from changes observed in the past and are well in excess of normal variations caused by solar cycles, ocean currents, changes in the Earth's orbital parameters and other natural phenomena," it added.

It called for supporters of the U.N.'s Climate Change Conference to produce "convincing observational evidence" supporting their claims of dangerous human-caused global warming and other changes in climate.

Zybach, 61, who is based in Cottage Grove but began studying forests in Jackson and Josephine counties in the late 1980s, acknowledged that many scientists would concur with the society's and DellaSala's conclusion.

Zybach said he believes that's the product of a "herd" mentality fueled by politics, which results in anyone questioning their views being vilified by the majority.

"Skeptics are supposed to be at the core of science, not on the fringe," said Zybach who focused on the study of historical ecology while earning his doctorate's degree at Oregon State University. His research was on the practice of woodland burning by American Indians and catastrophic wildfire patterns of Western Oregon. He is the program manager of the nonprofit Oregon Websites and Watersheds Project, Inc. which can be found at www.orww.org.

In particular, Zybach questioned the reliability of computer models to predict global warming.

"Nobody knows what the weather is going to be in five minutes," he said. "So how can they accurately predict what it is going to be like in 50 or 100 years?"

His research also rejects claims that global temperatures in the past century are exceptions to the norm. It was much warmer 5,000 to 7,000 years ago, he said.

"We also know the 1930s was warmer and drier than the past 100 years," he said. "Yet there was a lot less carbon dioxide in the air in the 1930s."

In turn, it was cooler from the 1940s into the 1980s, he said.

"The data just doesn't support their assumption," he continued. " ... We need to get away from science as politics or science as religion. We need to get back to scientific methodology."

Zybach insisted he has no political ax to grind.

"I'm apolitical, staunchly so," he said.

"We do have some real problems on this planet — infant mortality, overpopulation, wars," he added. "We need to direct our resources at human misery, not at problems that don't exist."

Reach Mail Tribune reporter Paul Fattig at 776-4496 or pfattig@mailtribune.com.