(CNSNews.com) - Many scientists and politicians continue to blame modern-day industrial emissions as the leading cause of a problem known as global warming, but a spokesman for the conservative environmental group Greening Earth Society warns that volcanoes pose another environmental threat -- global cooling -- a problem that is often ignored.
The National Academy of Sciences (NAS), in a study commissioned by the Bush administration, labeled the fossil fuel emissions produced by factories and automobiles the leading cause of global warming. Senators Joseph Lieberman (D-Conn.) and John McCain (R-Ariz.) also teamed up recently to call for a comprehensive cap on America's production of the gases that are believed by many to cause a greenhouse effect on the earth.
However, a volcano, according to Ned Leonard of the Greening Earth Society, "is an example of one of those huge natural sources of the greenhouse gases that get overlooked. They put a lot of ash in the air, but that falls out pretty quickly. But the sulfates, you know, they get injected pretty high up, so they're going to be affecting [the] climate for a while."
In recent comments, McCain blamed U.S. industries for producing "approximately 25 percent of the total greenhouse gas emissions," and stated that the U.S. "has a responsibility to cut its emissions ..."
"I don't think there's any doubt that if you continue to build up greenhouse gases, the earth will warm," said Dr. Robert C. Balling, Director of the Office of Climatology at Arizona State University. "The big question there is, by how much?"
However, Balling does not share Lieberman's and McCain's views on global warming.
"The dinosaurs walked the earth and it was much warmer than it is today and there were no humans back then driving around in SUVs," Balling said.
"Historically, it's been shown that major volcanic eruptions have a cooling effect on the planet for a year or two. If you go back and look at Krakatoa for example back in 1808, I mean these [eruptions] had a tremendous cooling effect on the planet."
Regarding the current eruption of Italy's Mt. Etna, Balling said, "It is not up to that level yet (Krakatoa), but even in the last 10 years, we've seen some volcanic eruptions come along and cool down the earth." A volcanic eruption can "dirty up the stratosphere -- that blocks incoming radiation ands cools the earth," he added.
Chip Knappenberger, a senior researcher with New Hope Environmental Services at the University of Virginia, also studies how volcanoes affect the global climate. "The largest climate effect that volcanoes have today is by explosive eruptions that blast a lot of material high into the stratosphere, say five to eight miles up," said the senior researcher.
"And when you get materials up there like dust, it stays up there for a long time because it's out of the active weather zone. So, you have material that doesn't get rained out or scrubbed out of the atmosphere very easily, so it stays up there for a year or two or three or four."
Knappenberger summarized that "those dust particles act to reflect back incoming solar radiation. So basically, you put a reflective layer around the earth and it reflects incoming sunlight and what happens is it leads to a cooling of the surface."
"So [with] major eruptions like Mt. Pinatubo [in the Philippines] back in May of 1991 -- you can see a cooling signal if you look at global temperatures for a year or two or three after that explosive eruption," Knappenberger explained. "You need something that has enough force to actually eject material that high. You need to get it up there many thousands of feet -- many thousands of feet to have any sort of climate effect that's not just local."
Leonard added that major volcanoes such as Pinatubo and Krakatoa are "obviously belching more CO2 into the air than the industrialized nations would, over some period of time, certainly over the course of years."
Balling supports President Bush's refusal to sign the Kyoto international global warming treaty, a decision that triggered a lot of criticism of the president from Democrats and environmentalists here in the U.S. and from the leaders of other nations who signed off on the Kyoto Protocol.
"I think everyone recognizes that even if the United States had been on board and even if everyone participated fully, you still don't have much of a climate impact by the middle of the next century. The impact of adhering to the Kyoto protocol is on the order of .03 degrees that we save the earth," Balling said.
"The idea that they're somehow going to spare the earth of global warming because of Kyoto is crazy," said Balling. "And everyone knows that. It's not a secret."
Critics of the Kyoto global warming treaty argue that the deal has a misnomer, that it isn't global since some of the world's leading polluters like China, India and Mexico are exempt from having to reduce their industrial emissions.
Balling also believes environmentalists exaggerate the problem of global warming.
"If they haven't noticed, there were ice ages long before humans got here. And the ice ages somehow came and went and came and went," Balling said. "The earth would warm up and we even had a climate optimum a thousand years ago where the temperature of the earth would have been two degrees warmer than today and I don't think anyone believes the humans did it."
Knappenberger believes global cooling is as much a reality as global warming.
"If you look at these paleo-climate records, where they push back temperatures maybe 1,000 years on annual resolution ... now they're not from thermometers, they're from tree rings and coral rings and glaciers ... you see that temperatures from about 1,000 years ago up to about 1900 declined. So there was a 900-year decline in temperatures and then there was a rise in the last 100 years," he said.
"So if you were going to make some sort of prognostication of what the next 100 years might be, well nine out of the last 10 hundred years, there's been a temperature decline. So at least you would think you might entertain some notion that there's a possibility that the temperature might decline."
The studies that McCain and Lieberman base their conclusions on do not factor in volcanic eruptions. "One of the problems that I have with something like the Intergovernmental Panel on Climate Change and looking at these scenarios of what the future climate of the earth's going to be like in a hundred years," Knappenberger explained, "is that none of these scenarios ever show you what might happen if the earth is cooler in a hundred years."
"And you might [ask], how could the earth be cooler in a hundred years? Well, all sorts of natural things might conspire to make [it] cooler in a hundred years," Knappenberger said. "Maybe we have a couple of volcanoes go off, the sun goes through various cycles and all sorts of various things that can happen."
Knappenberger noted that, "All the projections in climate are coming from computer generated models." He added, "The only thing that computers are interested in is that they change the CO2 concentration. But, they don't fire off volcanoes every once and a while in the model."
Balling explained that in reality, "volcanic eruptions are going to come and go forever and they'll perturb the pattern and make it difficult to identify the warming signal." Further, he noted that "the sun is not perfect. It varies its output. That's a complication we have to look for."
Numerous attempts were made to discuss 'global cooling' with environmental organizations such as the Union of Concerned Scientists, Friends of the Earth, Natural Resources Defense Council, Environmental Defense Fund and the Global Climate Coalition. The groups either did not return telephone calls or refused comment when contacted.
Former Vice President Al Gore's book, Earth in the Balance, acknowledges the influence volcanoes have had on planetary climate and weather, specifically the 1815 eruption of Tambora in Indonesia. Gore describes the worldwide cooling effect that Tambora had, noting, "The Great Subsistence Crisis caused by the cold spring in 1815 and throughout the next 18 months led to a flood of immigrants from Maine, New Hampshire and Vermont flowing into the western frontier and the south states."
Gore, however, warns his readers, "In the course of a single generation we are in danger of changing the makeup of the global atmosphere far more dramatically than did any volcano in history, and the effects may persist for centuries to come."
In defiance of those already onboard the global warming bandwagon, Balling laughed. "You can pass all the Kyotos you want and volcanoes don't care."