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Henry David Thoreau as global-warming researcher?

Comparing the dates Thoreau recorded of flowers in bloom with those today shows powerful evidence that global warming is taking place, say researchers.

By / March 20, 2012

Writer Henry David Thoreau was a devoted diarist who discussed various natural topics in his journals, including the dates on which flowers bloomed for the first time in the spring.


As spring officially begins today, America’s poet laureate of the changing seasons is getting renewed interest for his contributions not only to literature, but modern-day science.

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Britain’s The Guardian newspaper recently reported that the journals of Henry David Thoreau have been recruited to glean crucial insights about global warming. Thoreau, a studious amateur naturalist, recorded the date of first spring-time blooms for a wide variety of plants in his native New England. But comparing Thoreau’s observations with more recent data, Boston University researchers have concluded that today’s flowers are blooming about 10 days earlier – powerful evidence that the Earth’s temperature is rising.

“We had been searching for historical records for about six months when we learned about Thoreau’s plant observations,” Richard Primack, a biology professor at Boston University, told The Guardian. “We knew right away that they would be incredibly useful for climate change research because they were from 150 years ago, there were so many species included, and they were gathered by Thoreau, who is so famous in the United States for his book, Walden.”

Thoreau was a lively and voluminous journal writer who chronicled a great many topics, and readers can get a good idea of his talents as a diarist in The Journal: 1837-1861, a one-volume softcover abridgment of the journals published by New York Review Books in 2009.

To read the journals is to be reminded that if Thoreau were still around, today’s first day of spring would probably be noteworthy for him. “Seasons mattered deeply to Thoreau,” the book’s editor, Damion Searls, tells readers. “Months mattered to him too: his first book was organized as a week, and his second, Walden, as a year . . .”

In honor of today’s official start of spring, here’s a Thoreau journal passage from 159 years ago today – March 20, 1853:

“The peculiarity of to-day is that now first you perceive that dry, warm, summer-presaging scent from dry oak and other leaves, on the sides of hills and ledges. You smell the summer from afar. The warm makes a man young again.”

Fitting sentiments for the first day of spring, 2012.

Danny Heitman, a columnist for The Baton Rouge Advocate, is the author of “A Summer of Birds: John James Audubon at Oakley House.”


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