He is especially well-known for his study of James Joyce's literary concept of "epiphany," his definition of Romantic natural histories, and his coinage of the phrase "Urbanatural roosting," an idea which links urban with natural modes of existence and argues for ways of living more lightly on the earth, for inhabiting our planet the way animals do, by altering our environments without harming those same environments.

He was a member of the selection committee for the Sam Rose '58 and Julie Walters Prize at Dickinson College for Global Environmental Activism,[2] a $100,000 a year award to a major environmentalist whose impact has been powerful and fully international.

Recipients so far have included Bill McKibben (author and climate activist), Lisa P. Jackson (Barack Obama's first EPA administrator), James Balog (video and still photographer of melting glaciers and icecaps), Mark Ruffalo (actor and river activist), Elizabeth Kolbert (Pulitzer Prize-winning environmental writer for The New Yorker and professor at Williams College), Brett Jenks (CEO and president of conservation organization Rare), and Our Children's Trust (the organization that supports 21 young people—aged 11–22—who have brought suit against the federal U. S. government, claiming that the climate of the earth is being damaged in ways that threaten the youths' rights to life, liberty, and the pursuit of happiness); and, in 2019 to the Natural Resources Defense Council (NRDC).

He has also won the Lindback Award for Distinguished Teaching[4] (1992-1993); selected by fellow faculty members, it recognizes superior educators in New Jersey, Pennsylvania, Maryland, Delaware, and Virginia.

The Teaching Company selected Nichols as one of the approximately 100 professors chosen to video and audio tape (also download) as part of their Great Courses Program; he has so far produced 24 lectures on "Emerson, Thoreau and American Transcendentalism."

In recent years, he has delivered keynote speeches and lectures in countries around the world: in England, Ireland, Puerto Rico, Portugal, France, Italy, Morocco, Cameroon, India, China, and Japan.

[7] Sarah Freierman, of The New York Times, says of the project: The multidisciplinary application of Nichols' research has been praised not only by literary critics and environmentalists but also by urban planners and architects such as Charles Morris Anderson.

Likewise, the site shows how human culture and urban ideas have helped to make natural spaces more livable: strict architectural regulations in the Adirondacks and in national and state parks, careful use of roads and trails throughout natural areas nationwide, and detailed rules for living with nonhuman species in wild and wilderness areas (hunting and trapping regulations, catch-and-release fishing streams, and strict protections for even the wildest species: rattlesnakes, wolves, and grizzly bears).