Summer 2004
Yesterday's Forecast
Photo by Leo Kim
Bryan Shuman
Assistant professor, geography
Education
B.A., Colorado College; Sc.M., Ph.D., Brown University
The best thing about field work is…
"The adventure of getting dirty, exploring new places, and seeing things that no one has seen before."
If he could travel back in time…
"I'd love to see a mammoth or a mastodon or a ‘megabeaver'. I'd also like to witness the draining of the enormous Montana lake that carved the Columbia River gorge and coulees of eastern Washington."
At home he…
Changes diapers and plays with his newborn son.
A tale from the trail in New Mexico
"I woke up in the middle of the night to a mountain lion growling at me as I slept out alone, without a tent, on a gorgeous starry night. The mountain lion was only about six feet away. I will never forget the sight of its eyes reflecting in the light of my flashlight or the sounds of it screeching at me and me yelling at it!
Bryan Shuman spent six months after college hiking the Appalachian Trail. A few years later, after finishing graduate school, he traveled the path that runs along the Continental Divide from Montana to New Mexico. Although he embarked on both journeys to unwind and relax, the trips also proved educational.
The landscapes through which each trail passed were very different: Although the Appalachian Trail skirts some of the most populous and longest-settled regions of the United States, the woods and wilds that cloaked the path seemed relatively untouched by human encroachment. By contrast, Shuman recalls, the western trail, which runs through some of the youngest and most sparsely populated states in the country, often traversed heavily logged lands and sometimes followed the ruts made by off-roading vehicles.
To Shuman, a geologist and geographer, the scene was proof that enormous environmental change can happen in the span of a few short years, particularly when people are involved.
Today an assistant professor of geography, Shuman remains intensely interested in environmental change. But it's not just human development that affects the landscape; the earth's surface is constantly in flux—molded by forces as powerful as volcanoes and as gentle as moss. Since its inception, our planet has undergone innumerable makeovers. "Landscapes are always changing in ways that we don't necessarily observe," Shuman says.
Shifts in climate, in particular, can dramatically reshape the environment. It's one of the reasons why Shuman and other scientists are particularly keen on understanding global warming. An incremental uptick in world temperatures could affect ocean levels, wind patterns, species migration, and desertification. But while meteorologists have documented an overall shift in temperatures over the past century, they have only spotty data from past centuries with which to compare the current trend. What was the weather like in, say, the sixth century? What was the trend in temperatures prior to the Ice Age? What was the average rainfall in during the reign of the dinosaurs?
Rocky past sheds light on the future
As a paleoclimatologist, Shuman seeks to understand climate shifts of the distant past. The most reliable clues to bygone climates can be found in the earth's crust. In New Hampshire, for example, fossils tell us that pine trees dominated the landscape 10,000 years ago—probably a sign of dry times, Shuman says. Rock formed 8,000 years ago, however, shows that hemlock and beech trees dominated the landscape—likely evidence of rainy climes. "But we don't know for certain if that's because of climate, or something else," Shuman says. Some scientists have suggested that the spread and domination of such plants may have more to do with the size of the seeds and their dispersal, for example. Without corroborating evidence, it's impossible to know whether plant fossils are an accurate measure of climates.
Shuman specializes in the study of lakes—specifically, of buried shorelines. As the surface of a lake rises and falls according to cycles of precipitation and drought, new layers of sediment are put down over time. By pulling sediment cores from ancient lakebeds, Shuman is able to determine when water levels rose and fell. So far, his studies of New Hampshire lakes have shown results that correspond with climate histories developed with plan models.
Lessons for our climes
Studying past climates also offers some sobering lessons for today—particularly for Minnesota. "The evidence is that forests change dramatically within 50 years," Shuman says. "And lakes can change even more rapidly than that. So if the climate changes as quickly over the next century as people have predicted, we can expect Minnesota's landscape to look quite a bit different [in 100 years] than it does now."
Having arrived in the Land of 10,000 Lakes just over a year ago, Shuman is eager to expand his research to Minnesota's famed waters and forests. Understanding the changes they've endured over time may help us understand the changes they're likely to undergo in the wake of global warming.
"We depend on forest resources and water supplies, so it's really important to know how, if climate changes, all these resources will change," Shuman says. "And one of the things I can tell you is this: If your climate changes, you can expect your forests to change. You can expect your lakes to change, too." And that's serious business for the state of Minnesota.