Seeing clearly: UMass scientist finds his research fodder for both sides in climate change debate
UMass scientist finds his research fodder for both sides in climate change debate
Monday, November 23, 20091
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AMHERST - Douglas R. Hardy was wary of releasing his most recent research into the disappearing glaciers of Mount Kilimanjaro.
With a clarity similar to the view on a cloudless day from the top of Kilimanjaro, Hardy, a University of Massachusetts geoscientist, could see the impact of the study coming from miles away.
Kilimanjaro, Tanzania's white-capped pinnacle standing 3.6 miles above sea level at its peak, has become an icon of global warming on both sides of the debate.
Its melting 11,700-year-old glaciers were featured in "An Inconvenient Truth," former Vice President Al Gore's environmental alert.
Those same glaciers also fuel arguments used by global warming detractors, who say the research data support their claims that forces other than climate change, such as deforestation, are behind the thinning ice.
And like the glaciers he studies, Hardy's research and his statements are fodder for both sides.
It can be difficult to conduct scientific research into a politically charged topic, said Hardy, who says his research proves global warming's impact on the glaciers. He says it's disheartening to see his statements used to bolster the arguments global warming skeptics.
"It's a little depressing to be used as an illustration or example of someone who is supporting the manipulation of science," said Hardy in a telephone interview from his Vermont home.
Hardy tries to be fully accurate with his words and his research. He doesn't make bold predictions and freely notes the weaker points of his own work. In 2004, Hardy said it was too early to tell whether global warming was affecting Kilimanjaro's glaciers.
Global warming is so obvious to Hardy that he doesn't feel it is necessary to oversell its impact. However, it is this caution and honesty that has made Hardy a darling of the denialists.
In his most recent paper, Hardy and his colleagues at Ohio State University revealed that Kilimanjaro's glaciers are disappearing due to a drop off in precipitation, a side-effect of global warming.
In the days after his research appeared in "Proceedings of the National Academy of Sciences," global warming deniers used Hardy and his most recent research as evidence that global warming is a myth. The relationship between alterations in precipitation patterns and climate change was largely unmentioned.
Under a subheading "Precipitation Not Temperature," Tony Pann of the Baltimore Examiner cites Hardy. Hardy is also quoted in a Seattle Times article "Kilimanjaro is not a victim of climate change." Writers for freerepublic.com and climatechangefraud.com also mention Hardy.
"The denialists and the general public see the loss of ice due to precipitation as distinctly different than the loss of ice due to temperature," Hardy said. "They don't understand that temperature and precipitation changes are one and the same in terms of changes on the global scale of climate."
This isn't the first time Hardy's work has been used to discredit global warming. In 2005 Hardy was footnoted in Michael Crichton's "State of Fear" as dismissing the idea that global warming had anything to do with Kilimanjaro's ice retreat - a point Hardy refuted in a 2005 Boston Globe article.
But proponents of global warming also cite Hardy to support their arguments. Hardy has been cited as supporting climate change in publications that include the New York Times, the National Post of Canada and on National Public Radio.
"Working on Kilimanjaro has really taught me the importance of being very careful, as a scientist, to communicate carefully about what I know," Hardy said.
A mountain as a laboratory
Hardy has been studying the glaciers of Kilimanjaro since 2000, making 12 trips to its summit to conduct such tests as collecting ice cores, fixing weather stations and measuring ice sheet thickness.
There are opinions and theories as to why, but one thing that can't be refuted is that the ice on Kilimanjaro is shrinking, and the rate picked up dramatically this decade.
Between 2000 and 2007, Hardy and his team learned that the area covered by glaciers on the mountain has decreased by 26 percent.
Comparing ice coverage shown in aerial pictures taken in 1912 to pictures taken in 2000, overall ice coverage has dropped by 85 percent. In 1912, about 12 square kilometers were covered in ice. In 2000 there were only 2 square kilometers covered in frozen water.
"That's three-quarters of a square mile - that's all that's there now," Hardy said.
The thickness of the remaining ice is also declining.
Between 2000 and 2007, the thickness of the northern ice field declined by 2 meters. A glacier on the south side of the mountain lost about 5 meters over the same time period. From June 2008 through February 2009, the northern ice decreased in thickness by another 1.5 meters.
Hardy's latest study, which analyzes an ice core taken from the mountain in 2000, finds evidence of melting and refreezing, which takes the physical form of bubbles in the ice, at the top of the core. This suggests that recent history is the only time in the glacier's almost 12,000 year reign that extensive melting has occurred on the mountaintop.
"It's pretty dramatic," Hardy said. "Every time I go up there I see new areas uncovered that were formerly covered by ice. I see the ice getting thinner. A lot has changed."
But why?
Hardy said glaciers on Kilimanjaro are disappearing mostly because Tanzania's climate is changing. It's becoming drier. Some of the most recent evidence of melting on the mountain is likely due to the year-and-a-half-long drought East Africa has suffered.
This tidbit supports global warming denialists' argument that Kilimanjaro's glaciers aren't disappearing due to climate change; it just hasn't rained in a while.
"I don't think any of us who are working there have any doubt that the current ice loss is related to global warming," Hardy said. "The snows or Kilimanjaro come and go. There's nothing new about this except that we're seeing less than we ever have before."
Global warming isn't just about temperatures rising, it's also connected to how changes in temperature affect global weather patterns.
In Kilimanjaro's case, the drier climate reduces snowfall, which in turn decreases the snowy insulation between sun and glacial ice, thus melting the ice. Hardy blames the reduction in precipitation on warmer temperatures in the Indian Ocean. A study released in 2007 found that over the last 40 years the ocean's temperature rose by 2 degrees Celsius, giving rise to higher atmospheric temperatures.
A warmer Indian Ocean is impacting the atmospheric circulation, or winds, in the area, resulting in less precipitation, less snowfall, and thinner glaciers, Hardy said.
"For people who think about global warming a lot, this is not a problem," Hardy said. "All these things are part of global warming or a result of global warming.
"Unfortunately too many in the media and people who want to deny global change seize on this point and say that this is an insulation issue and not global warming," he said.
Making his case
When preparing a report on the data, Hardy wanted to steer clear of making predictions or bold statements about the glaciers, but a number of his colleagues disagreed. The paper predicts the glaciers on Kilimanjaro will be gone within the next three decades.
"There's a rich history of people predicting the demise of the Kilimanjaro glaciers within a 20-to-30-year time frame going back to the 1900s," Hardy said.
Of course, those predictions didn't come to pass.
"That looks really bad for us as scientists among those who are really persnickety about details," he said. "People have utilized these bold statements to find the weaknesses and point them out."
Hardy doesn't mind discussing the weaker points of his data. For example, the ice core on which many of the findings are based has only three "anchor" points in it. Anchor points are areas within the core, a long tube of ice, that provide scientists with the ability to date the material. For the most part scientists are hoping to find a chunk of carbon to use as an anchor. A dead bug frozen in the ice is a good example of an anchor point.
Kilimanjaro didn't have anything as obvious as an animal trapped in ice on which to base the dating. Scientists instead had to rely on spikes in chemical compounds compared against known events to make their time line. For example, they found a layer with enriched levels of radioactive isotopes, which they were able to link to nuclear testing conducted in 1952.
"It's a little shaky," said Hardy, who defended the research as the best anyone has been able to devise, but added that he has shipped off some samples to Switzerland where scientists have created a novel way to date ice cores.
But Hardy's vigilance has caused him some stress.
"Some of my caution has been responsible for the denialists," Hardy said. "They use me as an example of a scientist who doesn't go along with this global warming bandwagon."
Hardy doesn't spend much time correcting people who cite him to support claims against global warming. And he doesn't plan to stop being critical of his and other scientists' climate research.
Hardy is in pursuit of the truth and although he resents his words being twisted to support causes he does not agree with, in the end he believes he'll be vindicated.
"The reality of global warming is so powerful that there is no reason we shouldn't just stick as closely as possible to the interpretations that we're fully confident about," Hardy said.
