A few summers ago, environmental history professor John McNeill traveled to a small island on one of Ontario's Muskoka lakes, where he and an Austrian colleague had sequestered a dozen geologists, archaeologists and other experts who are world-renowned for their study of soil.

As with any academic conference, the members of the group spent their time presenting original research and engaging in scholarly discussions. Their goal had been to examine the way different societies have used -- and abused -- their land and how their actions changed the course of history.

"Soil is the foundation of life," McNeill says, "and yet it is almost completely neglected by historians, even environmental historians."

This is what intrigues McNeill about environmental history -- approaching subjects from both narrow and broad perspectives to better understand the relationship between people and nature.

For the two decades he has been on the Hilltop, McNeill's research has explored the environmental histories of war, mountains in the Mediterranean and deforestation in Southern Brazil, among many others. In the process of advancing these sub-disciplines, he became an expert in world history in general. Since 2000, he has published two comprehensive books, "Something New Under the Sun: An Environmental History of the Twentieth-Century World" (2000) and "The Human Web: A Bird's-Eye View of World History" (2003), both printed by the trade publisher W.W. Norton & Co.

"The way I look at these things is that historians collectively need to work on all scales," McNeill says. "Work on the macro studies -- the broader studies -- is important ... and of course the best micro studies are informed by the bigger picture. ... But we should work in a way that these are complementary to each other."

This is something he tries to impart to the doctoral candidates he mentors as director of the history department's graduate studies program. George Vrtis (G'06), who defended his dissertation last year, says McNeill would prod him to think deeper about his thesis subject, the environmental history of a mountain range in Colorado.

"He kept asking me to think of the mountain range in terms of the region, of the country, of the Americas, and of the world," Vrtis says. "That made a lot more work for me, but he was right."

McNeill is also known for asking his students to draw conclusions, not just compile data, says Linda Ivey, who earned her Ph.D. in 2003 and now teaches at the University of California, Santa Cruz. She said he typically responded to meticulously researched papers with the question, "So what?"

"It might sound harsh, but he would say, 'You can't just tell stories, you have to communicate why this research is important,'" she says.

McNeill holds his own research to the same standards, says Timothy Beach, director of the Center for the Environment and associate professor of geography and geoscience.

"What puts him above all of the other really great historians is that he seeks out scientists and science info and other primary sources rather than relying on what's already been said about something," Beach explains.

The Muskoka Lakes gathering is a perfect example of this, Beach adds. When McNeill became interested in soil as a sub-discipline, he drew on the knowledge of scientists with soil expertise, including Beach. The collection of papers McNeill co-edited from the conference were published earlier this month in a book called "Soils and Societies: Perspectives from Environmental History" (The White Horse Press, 2006).

"He's a scholar's scholar ... he is always ready to read anything," Beach says. "The amount of material he pores through is amazing because he wants to be as thorough as possible before he passes historical judgment."

That diligence is one reason Beach uses a few of McNeill's previous works in his own courses, specifically the award-winning "Something New Under the Sun." It is also part of the reason McNeill was tapped a number of years ago to help develop a curriculum for the undergraduate course on world history, which McNeill occasionally teaches himself, says John Tutino, associate professor and chair of history.

"He's definitely one of the most productive scholars in the department," Tutino says. "Honestly, I’m not sure how he does it."

There was no summer break for McNeill as he continued another project that focuses on an unexplored thread in the fabric of environmental world history. The subject is yellow fever, which killed hundreds of thousands of people during the 17th and 18th centuries in the warm latitudes of the Western Hemisphere, in areas such as the Caribbean.

McNeill is studying many of the environmental transformations responsible for the spread of the disease during that time period, including the type of mosquito that transmitted it and thrived in the growing sugar plantations. He is also studying the precipitation patterns, not just to understand how they contributed to the epidemic, but to see if the patterns might predict future outbreaks.

Looking forward, not just backward, is another one of his traits.

"I think what is extraordinary about [John] McNeill is his angle of vision," Vrtis says. "He keeps asking you pull back your angle to see something new."