Climate Change Could Mean Extinction for These Pollinators by 2050
As extreme droughts increase in Europe because of global warming, scientists predict that important pollinators in Britain won’t be able to stand the heat.
Six drought-sensitive butterfly species in the U.K. face extinction by 2050 if greenhouse gas emissions continue, according to a study published Monday in the journal Nature Climate Change.
The six butterfly species found to be most sensitive to dry spells and extreme weather—effects scientists expect to worsen with climate change—were the large skipper, the speckled wood, the green-veined white, the cabbage white, the ringlet, and the carbon white.
Small and unassuming, butterflies may not seem influential in the environment, but because they pollinate plants and crops, they can be vital to the global ecosystem.
The study’s researchers, from the University of Reading and other universities and conservation groups across Britain, used data from a 1995 drought alongside drought projections for the future to predict that under business-as-usual global warming, widespread die-out is expected for these six species by midcentury.
Across the world from the British study, a humid 4,000-square-foot chamber at the Pacific Science Center in Seattle is home to hundreds of butterflies and colorful plant species that might be vulnerable to drought and habitat loss elsewhere.
Sarah Moore, life sciences manager at the center, oversees the exhibit, which is called the Tropical Butterfly House. Butterflies often have exclusive relationships with specific plants, according to Moore, meaning some plant species rely on them for survival.
Another reason for concern about a die-off is that these flying insects were fated to die differently.
“In an ecosystem...they’re a food source for a lot of other animals. If they were gone, whatever else is preying on them would take a hit,” Moore told TakePart in a phone interview.
The British study’s implications go beyond the plight of one species, said Moore, agreeing with the paper’s authors. Because of their habitat needs and visibility, butterflies are often the first indicators for the struggles of other species. They act as a warning that habitats are in danger.
“They’re observable. There could be other insects suffering the same way, but butterflies are pretty easy to find and count and keep track of,” said Moore. “I think for that reason alone they’re a good canary in a coal mine. They’ve been used that way already for pesticide use.”
Pesticides like Monsanto’s Roundup have historically decimated monarch butterfly populations by eliminating from fields the only plant they use for egg laying—milkweed.
Tom Oliver, one of the study’s authors and a researcher with the NERC Centre for Ecology and Hydrology, hopes the paper will help make the case for stronger restrictions on carbon emissions at an international meeting discussing climate change in Paris in December.
Moore sees the butterfly decline as just one of many consequences of climate change that we’ll see in the coming years.
“Climate change is going to change the relationship between things that coevolved,” she said. “It’s going to cause a whole lot of domino effects.”
Butterfly populations in the U.K. have been declining for years. According to a 2011 report by British charity Butterfly Conservation, 72 percent of butterfly species in the U.K. declined in number between 1995 and 2010.
On a global level, the monarch species is particularly vulnerable, having lost about 90 percent of its population in the last two decades.