"The climate scientists have really shown that global warming is happening. What we've found is that it's not only happening but it's having a big impact," she said.
In an analysis of 172 species of plants, birds, butterflies and amphibians, Parmesan found that spring events such as egg-laying or flower-blooming advanced 2.3 days on average each decade.
Her analysis of studies of 99 species of birds, butterflies and alpine herbs in North America and Europe found these species' ranges have shifted northward an average of about 3.8 miles per decade.
Most striking, she said, was the case of the sooty copper, a butterfly common near Barcelona until recent decades. These days, however, residents of the Spanish city must travel about 60 miles north to find this butterfly.
Meanwhile, the sooty copper's northern range, which once ended in Austria, has shifted into Estonia during the past five years, Parmesan said. The insect had previously never been seen in that Baltic nation.