cover_story_2 (2006-39)

ORNL Crew water taking water samples from Walker Branch area 1980 (above) and 1990 (below).

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The debate over climate change is over. A majority in the world’s scientific community acknowledges global warming as both a fact and a dilemma.

To what extent mankind’s activities affect that change and how it will ultimately affect mankind is still open to debate.

At the root of the answers to those questions is the carbon cycle, the generation of carbon dioxide, both naturally and through deliberate burning of fossil fuels and other human practices such as land-clearing and agriculture. CO2 is the leading culprit among greenhouse gases released into the atmosphere that are behind global warming, or the gradual increase of the average temperature of the Earth’s atmosphere.

A group of distinguished researchers at Oak Ridge National Laboratory’s (ORNL) Environmental Sciences Division (ESD) is studying that carbon cycle and sharing its data with both the U.S. government and the worldwide scientific community. The Carbon Dioxide Information Analysis Center, established in 1982 at ORNL, has been the U.S. Department of Energy’s primary center for global-change data and information analysis since then.

The ORNL work gets little recognition from the general public, but its importance in informing other scientists and in helping direct government policy is hard to overestimate, even though the research and its ultimate conclusions take time.

“We tend to our research and let our publications speak for themselves,” says Gary Jacobs, the current director of the ESD, says. The published results circulate for other researchers to use as case studies and for government agencies that sponsor the research to develop policy, Jacobs says.

There are no ready answers to the problems involved in measuring the carbon cycle and its effects, as Jacobs acknowledges. But the only path to those answers is through careful research that’s sometimes difficult to conduct and even understand. But the word does get out.

Chris Irwin, a leader of the Katuah Earth First’s Knoxville-area organization, a group of environmentalists that often challenges human practices directly through protest, says he’s aware and appreciative of ORNL’s environmental studies.

A publication of ORNL more than 10 years ago, called Trends ’90, describing carbon contributions toward global warming was “invaluable,” he says. “It was absolutely important in influencing a lot of our understanding of climate change,” says Irwin, whose reputation in the Oak Ridge community has been largely derived from arrests while protesting nuclear-weapons development, another of Oak Ridge’s activities.

Initially a Department of Defense (DOD) and Atomic Energy Commission (AEC, now Department of Energy or DOE)-sponsored facility, ORNL has been an Environmental Protection Agency (EPA) client increasingly since the National Environmental Policy Act of 1969 was passed, requiring environmental impact statements on federally funded projects.

The ESD designed the environmental impact statement (EIS) methodology in 1970. The division doubled in size as it began conducting the EIS program that year, writing the statements and shaping the concepts of Environmental Risk Assessments that were codified and regulated by the EPA, according to Robert O’Neill, a theoretical ecologist who served on the ESD staff from 1967 until retiring five years ago.

That program “began a long relationship with EPA,” says O’Neill, leading to the development of the field of landscape ecology, which used new technologies such as satellite imagery to look at ecological processes on a large scale and allow the EPA to address regional problems of air and water quality. Landscape ecology had a major impact on the division, O’Neill says, followed in the 1970s, and ’80s and continuing today, by global carbon research.

Robert Van Hook, director of the ESD from 1989 to ’93, says the division became the world leader in carbon research in the late ’70s, when the National Science Foundation was funding the work and “the role of forests in the global carbon cycle was determined.” The DOE took up the funding in the 1980s, and, Van Hook says, the research results “enjoyed a far higher reputation in Russia and European countries and China than in the U.S.”

Van Hook, who moved up in the DOE chain of command in Oak Ridge before retirement in 2000, says the federal government began acquiring land in 1939 for the federal reservation that became Oak Ridge. All of the division’s research capability traces back to the Manhattan Project, the World War II program that developed the atomic bomb in a secret compound that was dubbed Oak Ridge. Scientists were involved from its beginnings, and when the 20,000-acre forest reserve that was allowed to revert to its natural conditions became the former Ecology Section of the AEC’s Health Physics Division’s purview in the 1950s, it had already been monitored and studied from an environmental point of view for more than 10 years.

So there is a tract of forestland with a watershed (Walker Branch) within the ORNL-studied parcel that has been reviewed for the ecological conditions of its soils, vegetation and watershed characteristics for more than 60 years, virtually undisturbed, Van Hook says.

During that time, the Oak Ridge scientific establishment went through years of development and production of nuclear weapons before much, if any work, was directed toward environmental research.

ORNL itself, once referred to as X-10, derived from the Manhattan Project. Alvin Weinberg, the theoretical physicist who was first director of the X-10 Physics Division at World War II’s end, became research director in 1948, and was named director of the entire laboratory in 1955.

A Renaissance-type who was a piano virtuoso as well as a scientist, Weinberg was among the first to recognize that nuclear science and technology had overrun the research into its effects on the environment and, indeed, on people who were not exposed to ionizing radiation directly, but indirectly, through the environment.

Human genetic responses to radiation were first studied at the lab, and, later, the effects of radiological releases into the environment on cattle and cow’s milk were documented.

Much of the lab’s effort was directed toward research into radiological isotopes until the 1960s, when the environment and ecological study grabbed up more of the focus, and that section was redubbed the Environmental Sciences Division. The original management contractor, Union Carbide, was replaced by Martin Marietta, which merged into Lockheed Martin, and the contract was ultimately taken up by a partnership between Battelle Corp., an Ohio technology firm, and the University of Tennessee, called UT-Battelle.

Through the UT-Battelle period, ORNL has become the site of the Spallation Neutron Source, a monstrous accelerator project that has been the nation’s largest technological investment at a $1.5 billion cost, incorporating one of the world’s fastest computers, capable of trillions of calculations per minute.

That supercomputer, dubbed Cheetah, has been used already to attempt to predict climate change in terms of temperatures, precipitation patterns and ocean-current fluctuations, well into the future.

John Drake, who along with David Erickson has been directing those projections in the ORNL Center for Computational Sciences (CCS), cautions that there are weaknesses and limitations in the computer models themselves, as well as their use for model projections, but discusses a “medium range” scenario for the middle to the end of the 21st century.

Using all available data, including that developed in the ESD, the model in current use predicts a warming of 1.1 degrees Celsius by mid-century and 2.3 degrees Celsius by the century’s end.

“Most of the temperature changes occur in the high latitudes near the poles, so in mid-latitudes, like Knoxville, one expects less severe temperature increases,” Drake says. He also says precipitation shifts will not likely affect these mid-latitudes in the northern hemisphere much, but temperature and ocean current changes will leave the polar icecaps more vulnerable to melting, and sea levels would rise by a predicted 25 cm.

The CCS’s work on climate projections is part of ORNL’s support of an organization called the Intergovernmental Panel on Climate Change, an organization established by the United Nations Environment Program and the World Meteorological Organization. The panel is to issue a five-year report in 2007 in which it will update projections and compare and critique computer models used in various countries to project future scenarios. Its assessment of the ORNL model will be interesting to see.

Meanwhile, the work in the ESD continues at that cautious research pace, with the hope of further perfecting the ORNL-developed model that would allow the supercomputer to ever-more accurately predict the nature and effects of climate change. Assisted by the nature of the Oak Ridge Reservation’s old forest and undefiled features, Richard Norby, a physiological ecologist, says the state of that part of the reservation has been a “tremendous resource” for research. His specialty field has been trees and their reaction to CO2 concentrations.

“Since 1996 we’ve directed research toward the forest, rather than just trees, creating simple models,” Norby says. The researchers expose plots in the forest to 500 parts-per-million CO2 in their air, contained in tent-like sheer plastic constructs, and measure the affects against those in trees that are in the natural setting. Norby says the initial response to the heavy CO2 concentrations, projected for the Earth’s ambient atmosphere in 2050, is more rapid leaf growth. Later, the process seems to stimulate greater root growth. It’s in the trees’ roots that carbon is sequestered, releasing less of that element to the atmosphere, an important consideration in the world’s vast forests, which release multi-megatons of carbon annually.

Carbon is also sequestered in soils, and that aspect of the carbon picture is being studied by Philip Jardine, a hydrogeologist who collects soils from around the country in addition to monitoring the soils of the ORNL reservation. “We have one-of-a-kind facilities for soil monitoring and measuring the effects of rainwater,” says Jardine, who mentions that any soil disturbance, such as plowing of fields for agriculture, “causes carbon burn-off that releases CO2 into the atmosphere.”

He’s an advocate now of “no-till farming,” which began in efforts to control soil erosion, because planting without tilling retains carbon below the soil’s surface and lessens CO2 discharges.

Patrick Mulholland, a biogeochemist, has been studying the Walker Branch watershed since 1980. He calls it “one of the few sites around the country where watershed monitoring has been conducted over time…. Monitoring tells us what’s happening and experiments tell us why.”

The studies began in the 1960s, measuring incoming and outgoing water and forest composition and development under changing weather and seasonal conditions. About the time Mulholland arrived, the research emphasis shifted to the effects of acid rain and “nutrient spiraling,” which is how stream ecosystems cycle chemicals between their biological characteristics and water and how those chemicals are transported downstream.

After 1993, precipitation manipulation led to climate-change-related studies, measuring impacts of precipitation differences on plants, soil and the stream in the watershed. “Walker Branch Watershed, among scientists, is probably the best-known studied watershed in the world,” Mulholland says.

That worldwide recognition is among attractions the ESD holds for researchers. “One of the best things about working here is the scope of the program, tackling problems that are global in nature,” says Jardine. “You walk down the hall and have a microbiologist, a geochemist and a statistician, all at your disposal,” he says, adding that the division has been the research center for “the cream of the world’s environmental scientists” at one time or another.

There has been turnover, because funding is always in flux, often on a project-by-project basis. Funding peaked sometime in the 1990s, and since 2000 it has run from $42 million that year up to $53 million in 2002 and back to $38 million this year. Employment of researchers and staff has gone from 133 to 183 and back to 149 in that period, according to figures assembled by Director Jacobs.

ORNL’s overall funding growth in the same period has spiraled upward each year, from $694 million to the current $1.08 billion, with a total workforce there of 4,100 today.

That comparison shows that the total science, national security and energy budgets and the payments for outside contract research have increased steadily under the UT-Battelle management of the lab, but the environmental research budget hasn’t kept pace.

Even so, Jacobs says his division has maintained its focus, which he describes as “to integrate observations, experimental measurements and existing data into simulations that inform us about how natural systems respond to human-induced as well as natural stress factors.” That’s a mouthful, but it’s an apt description of how much of science is derived.

Jacobs says his division’s work does ultimately affect some important government policy decisions. For example, Jacobs says, one of his scientists, Virginia Dale, is “working with Ft. Benning, Ga., to develop a simulation tool for future land use,” pointing to “how the DOD can meet its military mission while protecting ecosystems.”

Another way the ESD’s science influences policy is through participation on national committees, Jacobs says. “Virginia is a member of the EPA Science Advisory Board. In this capacity, she can provide scientific insights directly to the agency[’s officials] for them to then determine how to use [those insights] as they develop environmental policies.”

And, Jacobs says, “We’re still doing Environmental Impact Statements for the DOD and others.”

But he adds, “There is research that could be done. But it is not on the national agenda right now…research that should be done that we can’t do without the additional funding it would take for the equipment and the personnel.”

Still, Jacobs says, “We stay busy.” And to hear his researchers talk, it sounds like they do.

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