Track the effects of a warming climate on Concord, Massachusetts' plants and animals. This book describes how warming temperatures have altered other aspects, from the dates when ice departs from Walden Pond in late winter, to the arrival of birds in the spring, to the populations of fish, salamanders, and butterflies that live in the woodlands.

Thoreau s incredible eye and appreciation for the natural world have rightly led to his reputation as one of the first American ecologists. Before he could turn his botanical records into a book, Thoreau succumbed to tuberculosis, and his copious, arguably obsessive writings on the natural world languished for some time, Emerson noting that Thoreau had squandered his talents on the woods and had become the captain of a huckleberry party. But his writings have since been revered by many, and are now part of the canon of conservation biology and climate change. The meticulous notes Thoreau kept on flowers in Concord have in the hands of Richard Primack and his students evolved from charming and detailed records to actual data sets.Thoreau would no doubt be saddened to learn that 27 percent of the plant species he documented have disappeared, and another 36 percent are in such low numbers that their disappearance is imminent. Concord's mean annual temperature though has climbed by 4 degrees, and the flowers and trees each spring awaken far earlier than they did 150 years ago. Climate change is wreaking havoc on Walden, as it is the world over, and in this wonderful tour of Thoreau s data points Primack shows us how history informs the past, and how backyard natural history is one of the most important areas of scientific contribution, as it has been for centuries.
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