Henry David Thoreau, America's original hippie responsible for writings like Walden created primarily to torture high school English classes, was once criticized by his mentor Ralph Waldo Emerson for his lack of ambition and failing to use his intelligence for the greater good. Where Emerson alive now, he might be pleasantly surprised to discover that one of Thoreau's quirks is helping determine the effects of climate change.
As the Smithsonian reports, Thoreau was known for his obsession with plants and migratory birds and their public signalling of spring's arrival. He kept detailed records on over 600 different species of plants, running four to five miles a day to check on a single flower and its blooming time. These records languished in obscurity even long after Thoreau's other works such as Walden gained in popularity. Then, Dr. Primack of Boston University recognized these records' value for demonstrating the effects of climate change.
Upon investigation of the records, made difficult by Thoreau's focus on the beauty of nature and not so much the beauty of his own penmanship, along with collection of current flowering and migratory bird data, Primack and his graduate student Miller-Rushing determined that many native plants are flowering on average three weeks earlier than they did in the 1850s, when Thoreau was collecting his data. Flowering times got earlier with increasing temperature, but bird migration times were not nearly as temperature sensitive.
This is potentially alarming, because spring is a delicate balance between plants flowering, pollinators emerging, and birds carrying seeds at the right times. If plants are changing more in response to climate change than their pollinators or birds, they might be unsuccessful getting pollinated, leading to a loss of biodiversity.
Thoreau really only collected this out of personal interest. He was viewed as an oddity for this meticulous record keeping of seemingly useless information. I can only hope that someday, my pointless hobbies are just as useful.