Category: Dept of Geosciences

by Eric Goldscheider

He knew they were the stalagmites, calcium carbonate deposits on cave floors caused by the groundwater above dripping from the ceiling over long periods of time that he and his colleague, Francisco Da Cruz, had collected a few weeks earlier. But the last time he saw them they were cylindrical. They had since been bisected lengthwise and polished by a stonecutter in Sao Paolo, revealing their inner cores. Burns and his students will spend the next couple of years studying them for clues about the Earth’s climate tens of thousands of—possibly 100,000—years ago.

Burns and Da Cruz unwrapped the rocklike protuberances from their masking tape and pink soft foam encasing. Burns expressed satisfaction as they fitted them together, like pieces of a linear puzzle. A few had broken in transit, but overall he was pleased that they revealed “clean crystalline calcite,” and that they were nicely layered. On a scale from one to ten, these were eights.

With some luck, along with a good deal of methodical high-tech probing, these natural archives, which look like petrified overgrown parsnips, will yield a continuous record of rainfall patterns, temperature, and atmospheric conditions reaching well into the previous geological epoch, known as the Pleistocene. “It’s truly incredible how faithfully they record the climate,” said Burns, whose work on caves in Yemen during the 1990s helped pioneer this area of inquiry.

Burns’s research on stalagmites complements work by other scientists peering into the Earth’s climate history. Techniques include looking at tree rings, lake and ocean sediments, corals, and ice cores from polar regions as well as from high altitude ice caps in the Tropics found in the Andes, the Himalayas, and on Mount Kilimanjaro.

Part of the mission of the Climate System Research Center is to gather information from many sources, much of it generated at other universities, and decipher patterns. In a large round space in Hasbrouck, their desks ringing the turretlike room, a dozen post docs and graduate students crunch data from studies happening all over the planet, including UMass Amherst’s weather monitoring station documenting the slow but accelerating disappearance of the ice cap on Mount Kilimanjaro. The space, once the physical sciences library, has been Ray Bradley’s domain for seven years.

Bradley’s own research on climate, begun with his first trip to the high Arctic in 1970, has centered on the fluctuations of ice masses and on lake sediments in northern Canada. He has returned nearly every summer since, often for three months at a stretch. Last spring he led a two-and-a-half-week expedition to the northern reaches of Ellesmere, an island about 500 miles from the North Pole.

But with the publication of an article in the journal Nature in 1998, (with two colleagues), Bradley’s work has become a lightning rod for politicians anxious to debunk, ignore, obfuscate, and even ridicule the growing body of research showing that greenhouse gases threaten to wreak dramatic, unpredictable—perhaps even dangerous—changes in the climate system human civilizations have depended on at least since the last ice age receded 10,000 years ago.

That article, which tracked global temperatures for the last 600 years, and a subsequent article in the Geophysical Research Letters, which pushed the time frame back 1,000 years, represented a departure for Bradley. He and fellow researchers Michael Mann of Penn State and Malcolm Hughes of the University of Arizona were not so much interested in what had happened in the past but in predicting what the implications of a marked warming trend in the last 100 years holds for the future. Their conclusion was that the only variable capable of explaining this recent heating of the globe was the release of greenhouse gases, primarily carbon dioxide, into the atmosphere since the start of the industrial revolution. And that given current trends, we can expect the Earth to heat up even more in the next decades and centuries.

A graph they produced became instantly famous in global warming circles as the “hockey stick.” The United Nations Intergovernmental Panel on Climate Change (IPCC), whose evaluation of the impact of greenhouse gasses on climate led to the development of the Kyoto Protocols, published it, and it has been reproduced in almost every study since that predicts dire consequences if greenhouse emissions aren’t drastically reduced. The long vertical handle of the hockey stick represents the first 900 or so years, marked by a slight cooling trend. The blade, which turns dramatically upward, shows a marked warming trend in the last hundred years, coinciding with increased carbon dioxide (CO2) in the atmosphere. It shows that 1998 was the hottest year of the millennium and predicts significantly hotter temperatures in the next century and beyond.

“It became the icon of what was going on,” said Bradley during an interview in his bright second-story home office where he does most of his writing. On the wall behind his cluttered desk are photos from his early arctic adventures. Behind a glass bookcase, he keeps his collection of bound first editions, mostly tales of arctic exploration in the 19th century, a few even earlier. Bradley’s soft-spoken demeanor belies the impact his work has had on the climate change debate as well as the intensity of his feelings about what human beings are doing to their planet.

What he didn’t bargain for when he and his colleagues published those papers, but what he realizes in retrospect he should have anticipated, was the fury with which those having a vested interest in what he calls “the carbon economy” would attack not only his work but also him personally. The hockey stick “became the focal point of the venom and diatribe of the so-called climate skeptics,” said Bradley. “You publish a paper and you expect people to challenge it and ask questions, but you don’t expect to be personally attacked for what you are doing, your motives questioned and your competence questioned. That’s not the normal way of science.”

Michael Mann, the lead author of “hockey stick” articles, concurs with Bradley that the great majority of climate researchers now believe that humanity is on a calamitous course. “I don’t think you would find a credible scientist in the community of scientists who would disagree with that proposition,” said Mann. “Most of the legitimate debate now centers on just how sensitive the climate is to increased greenhouse concentrations, but not whether or not the climate is sensitive to increased greenhouse gas concentrations or whether they are already having a detectable influence on the climate.”

Mann, who just moved from the University of Virginia to Penn State, was doing postdoctoral work at UMass Amherst when he coauthored the “hockey stick” articles. Bradley credits Mann with originating new mathematical approaches that were crucial to identifying strong trends.

Now Mann is among the scientists most willing to take a political role in fighting for general recognition of the scientific consensus on climate change. And, citing a special report, “As the World Burns,” in the May/June issue of Mother Jones magazine, ( http://www.motherjones.com/news/featurex/2005/05/world_burns.html ) Mann lays much of the blame for public confusion about the issue at the feet of the ExxonMobil Corporation. “There used to be a group called the Global Climate Coalition, a group of companies that pooled resources to fight legislation curtailing carbon emissions and to fund individuals who would challenge the underlying science,” but, according to Mann, “one by one the various companies started to pull out of the coalition. British Petroleum was one of the first. Shell has pulled out. ExxonMobil is by far the largest remaining member and by far the largest funder of this sort of disinformation.” According to Mother Jones, ExxonMobil in recent years has funneled more than $8 million to groups and individuals who “preach skepticism about the oncoming climate catastrophe.”

Last year Mann and some colleagues set up a Web site, www.RealClimate.org, designed to rapidly provide solid scientific information to combat the industry-funded disinformation they say is polluting the debate. The scientific consensus notwithstanding, the culmination of the political heat people like Mann and Bradley have experienced was an attack on the Senate floor by Oklahoma Republican James Inhofe. Two years ago he called the prospect of catastrophic global warming the “the greatest hoax ever perpetrated on the American people.”

Reflecting on this attack, Bradley said that up until a few years ago he and his coauthors “were just three guys trying to reconstruct the climate of the last 1,000 years.” He hadn’t given much thought to the implications of global warming. “Until then I was just a humble worker in the vineyard,” said Bradley, but the publication of those papers turned out to be “a life- and career-altering event.”

Bradley says he is sickened by the coordinated and well-financed campaign to discredit the data he and others like him are generating. Bradley maintains he could become “instantly rich” were he to renounce the hockey stick and become a spokesperson for the oil and gas industries. ExxonMobil has a record of offering lucrative positions to people who espouse skepticism about the impact of fossil fuels on climate. Last spring the energy giant immediately hired White House aide Philip Cooney when he resigned his post as chief of staff of the Bush administration’s Council on Environmental Quality. Just a few days earlier the New York Times exposed Cooney’s role in softening the conclusions of several government climate change reports.

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Looking back at his career so far, Bradley, 57, said he has come to see the implications of his work in moral as well as scientific terms.

He described his first trip to the arctic as a University of Colorado graduate student almost as a comedy of errors. A professor had obtained funding for a two-person expedition from the U.S. Army but instead he sent 10 of his students to get the most out of the grant. “We were very poorly equipped, we had nothing but freeze-dried food, I’m not even sure we had a rifle, it was crazy; the whole thing was a total shambles, but we survived,” he recalled.
In those days, said Bradley, “nobody would give a damn if the glaciers caught fire.” He was there for 100 constantly illuminated days and nights with temperatures hovering between 20 and 50 degrees Fahrenheit the whole time, and he vowed never to return. But when he got back to Colorado, “within a month I was planning my next trip,” he said.

He came to UMass Amherst as a lecturer in 1973, and in addition to going back to the Arctic almost every summer, he wrote articles and books including the standard textbook in his field, Quaternary Paleoclimatology: Methods of Paleoclimatic Reconstruction, published in 1985 and reissued in an updated edition in 1999.

Late last May and early June he went back to Ellesmere with three other researchers. A De Haviland Twin Otter plane, known as “the workhorse of the arctic,” out of Resolute Bay, one of the northernmost settlements in the world, dropped them off at research sites. Included in the 1,700 pounds of equipment they brought was a tripod and boring equipment they sent down through six feet of ice and 250 feet of water in order to retrieve 30-foot cores of lake sediment. Because runoff from the surrounding hills occur only once a year in this part of the world, the coarseness of the sediment in each layer gives a good indication of that year’s melting. With luck the cores will yield a record going back several thousand years.

This research aside, the steady diminution of the sheer quantity of ice Bradley has observed during the three decades he has been going to the arctic is worrisome not just as a scientist, but as member of the human community. Polar region ice cores, some as much as three miles long and yielding up to 800,000 years of climate data, show that hotter temperatures coincide with the rise in CO2 concentrations in the atmosphere, which are now at 380 parts per million and are projected to climb to 760 ppm by mid-century, according to Bradley. To put that in perspective, says Bradley, it took 10,000 years from the end of the last ice age until the beginning of the industrial revolution for CO2 concentrations to rise from 180 to 280 ppm.

The speed of the changes now underway is unprecedented in human (and probably the Earth’s) history. The unpredictability of what this rapid buildup in greenhouse gases portends is vexing in and of itself.

“It’s criminal that we haven’t tightened the screws on gas consumption,” said Bradley, “and what’s so upsetting is that a lot of things could be done to cut down on CO2 emissions without causing major disruptions… we are reaping the benefits of our profligate lifestyles with no regard for what it’s going to do to the future.”

The forms that the impact of rising levels of greenhouse gases will take are still unpredictable, said Bradley, but the damage could be horrendous. The potentially widespread flooding of coastal regions caused by melting ice caps is often mentioned. The Environmental Protection Agency predicts that increased average global temperatures can be expected to cause an average two-foot rise in sea level on all U.S. coasts by the end of this century. But other consequences could include a marked increase in the frequency and intensity of extreme events like hurricanes and droughts, insect and disease migration to higher altitudes and latitudes, and even a disruption of established ocean currents that play a big role in how heat is distributed around the globe.

We are potentially facing a “total climate shift,” said Bradley, though it is still unclear where the tipping points are because “there are parts of the global climate system where we don’t understand the mechanisms.” For Bradley it boils down to “a question of whether our generation has the right to change the conditions of the world globally so that whatever the consequences are, our kids and grandchildren will have to deal with them.”

In the nearer term, he said, those most likely to suffer are the world’s poorest people who are already living in marginal climates. These are the people who benefited the least from the industrial revolution and who have contributed least to the problem. In the long run it is hard to say how the suffering will be distributed. But what Bradley believes with great certainty is that “it is unethical to dump this problem on our children and grandchildren who will have to fix something that we failed to deal with.”

There are signs that people in industry and the press are waking up to the dangers of inaction. General Electric, for instance, announced earlier this year that it plans to devote $1.5 billion annually to conservation and emissions reduction research. But deny and delay tactics have cost the world valuable time that could have been used to slow down a warming trend that already has a lot of momentum.

“It’s like pushing a car down a hill,” said Bradley, “and not knowing where it will go.” ?