Walden Warming: Climate Change Comes to Thoreau's Woods

Abstract

In the 1990s, Richard Primack, a botanist at Boston University, began investigating the effects of logging in Borneo with a broader concern about how human activity shapes environments. Roughly a decade later, Primack turned his attention more directly to the effects of global warming. Admitting that many in the United States perceive global warming as a distant threat (both geographically and temporally), Primack recognized that his work would have greater political and social ramifications if his data were collected closer to home. “It's easy for people to be nonchalant about or ignore a distant problem,” Primack notes, “but harder to remain unconcerned when it's up close and personal” (3). Primack chose to focus on Concord, Massachusetts, a town roughly 20 miles west of Boston which has seen unprecedented conservation efforts, and which would thus give Primack and his students ample opportunity to measure the effects of global warming on plants, ponds, birds, and insects. Primack planned to compare present-day data on flowering times and migratory patterns with those of previous decades, yet he was unable to locate records of this sort prior to the 1970s. His “eureka moment” occurred when a friend, environmental philosopher Philip Cafaro, mentioned that Henry David Thoreau had made meticulous notes concerning flowering dates of over 300 plant species in Concord in the 1850s (as well as the dates of ice-outs on Walden Pond and arrival times of migrating birds), part of his late-career project the “Kalendar” (4).