Tracking climate change through Henry David Thoreau's notes

BOSTON — With radar and satellites, a lot of hi-tech gear tracks climate change today.

Back in the 1850s, Henry David Thoreau kept detailed notes about plants and birds from his time at Walden Pond.

Boston University biology professor Richard Primack is now using those handwritten records to draw conclusions about how the environment is changing today.

For example, Thoreau was very interested in blueberries, so he recorded when those bushes flowered, leafed out, and when the fruit would mature.

In all, Thoreau took detailed notes on about 300 species in the woods surrounding the Concord pond.

“We managed to track down a copy of these unpublished observations of Thoreau and as soon as we saw these records in the fall of 2003, we knew this was fantastic,” explained Primack.  “This was a gold mine of environmental observations.”

Primack now wanders the Walden Woods himself, comparing Thoreau’s findings to the situation today.  “Plants are flowering about 10 days earlier in Concord than they did in Thoreau's time. Plants are flowering earlier because it's warmer now.”

Primack has also noted that trees are more responsive to climate change than wild flowers.  “This is a really interesting observation that no one had really discovered before.”

Finally, some bird species, such as hummingbirds, are arriving a little earlier than usual.

New England is a good place to track the effects of climate change, both because of archival notes like Thoreau’s, and because of what’s happening here.  “New England has warmed up about twice as much as the rest of the country. We've experienced a lot of disproportionate amount of warming in Southern New England compared to the rest of the United States, and you can really see the effects of climate change in many ways in all seasons,” said Primack

Some cold loving species, such as orchids and lilies, have completely disappeared from the Walden area, according to Primack.

Cox Media Group