Hill Heat

Climate scientists have long projected that human-induced global warming would make spring arrive earlier than normal, and it is – about 10 days earlier so far. On Tuesday, April 20, a group of scientists will discuss the ramifications for plants and animals across the country.

• Melanie Fitzpatrick, a climate scientist with the Union of Concerned Scientists, will moderate.

• Jake Weltzin, the executive director of the U.S. National Phenology Network and an ecologist at the U.S. Geological Survey, has found that an earlier spring creates “mismatches” for animals and plants that depend on each other. For example, it’s critical for butterflies to lay their eggs on the new leaves of certain plants. But many of these plants are emerging from dormancy earlier than normal, and butterflies’ reproductive cycles have not adjusted.

• Charles Davis, an assistant professor of evolutionary biology at Harvard University, recently discovered that invasive, nonnative plants in Concord, Massachusetts, that flower earlier are the “winners” in climate change. Using data taken by Henry David Thoreau, he found that native plants, such as lilacs, orchids and dogwoods, have maintained their historic flowering schedule and are disappearing from the woods around Walden Pond. His findings likely extend to all of New England.

• Anthony Westerling, an assistant professor of environmental engineering and geography at the University of California-Merced, has discovered that rising temperatures combined with early snowmelt are contributing to large forest fires in Western states.

• Erik Beever, a wildlife biologist, has been studying the pika, a rabbit-like mammal that lives in 10 Western states. He recently published a paper that found that the pikas’ mountain habitat is shrinking. He says the species may be an early-warming indicator of how alpine species will respond to global warming.

Call 866-282-2803 and provide the operator with the password: “spring climate change.”