Vanessa cardui, also known as a cosmopolitan. Credit: Stefan Pinkert A Yale-led study warns that global climate change may have a devastating effect on butterflies, turning their species-rich, mountain habitats from refuges into traps. Think of it as the ” butterfly effect “—the idea that something as small as the flapping of a butterfly’s wings can eventually lead to a major event such as a hurricane—in reverse. The new study , published in the journal Nature Ecology and Evolution , also suggests that a lack of comprehensive global data about insects may leave conservationists and policymakers ill-prepared to mitigate biodiversity loss from climate change for a wide range of insect species. For the study, a team co-led by Yale ecologist Walter Jetz analyzed phylogenetic and geographic range data for more than 12,000 butterfly species worldwide. The team was also co-led by Stefan Pinkert, an entomologist at the University of Marburg, in Germany, and former postdoctoral associate at Yale. They found that butterfly diversity is highly clustered in tropical and subtropical mountain systems: Two-thirds of butterfly species live primarily in the mountains, which contain 3.5 times more butterfly hotspots than lowlands. Yet those mountain ecosystems—and surrounding areas—are quickly changing as a result of climate change. According to the study, 64% of the temperature niche space of butterflies in tropical areas will erode by 2070, with the geographically restricted temperature conditions of mountains constantly shrinking. “The diversity, elegance, and sheer beauty of butterflies impassion people worldwide,” said Jetz, professor of ecology and evolutionary biology in Yale’s Faculty of Arts and Sciences and director of the Yale Center for Biodiversity and Global Change (BGC Center). “Co-evolved with host plants , butterflies form an integral part of an ecologically functioning web of life,” he added. “Unfortunately, our first global assessment of butterfly diversity […]