Widespread drought brought about by climate change is set to have a devastating effect on many of the UK’s butterfly species, with population extinctions predicted as early as 2050, according to a new report.
A study led by Dr Tom Oliver from the Centre for Ecology & Hydrology has found that six popular species of butterflies are particularly drought sensitive.
Climate change has altered the UK weather patterns to such a degree that a drought that was considered an anomaly when it hit in 1995 is soon to become an annual event.
The 1995 drought’s aridity was such that several butterfly types were devastated, before gradually bouncing back as the weather patterns and habitat returned to normal.
Oliver, though, fears that a “business as normal” prediction of how things are going will see such droughts coming back every year, dooming the Ringlet, the Speckled Wood, the Green-veined White, the Large Skipper, the Large White and the Small White butterflies as soon as 2050.
The researchers actually looked at the UK’s 28 major species, finding these six to be the most susceptible to drought problems.
The report, published in Nature, outlines a direct link between landscape and recovery: the more fragmented the habitat, the longer it took for populations to revive.
After looking at the 1995 event and how butterflies battled to recover, Oliver and his team used “state of the art climate models” to project what the frequency of drought events might be in the future, also taking into account changing CO2 emissions.
“We found that across the six species the projected impact of climate change was quite severe. I was quite surprised working with this climate data quite how many droughts we would expect up to 2050, 2100,” said Oliver.
“Under the low emissions scenario, they will happen every seven years. Under the severe emissions scenario, which is business as usual, it is every year.”
Widespread population extinctions of the drought-sensitive species are expected by 2050 under realistic predictions. “To limit these losses,” said Oliver, “both habitat restoration and reducing CO2 emissions have a role. In fact, a combination of both is necessary.”
The significance of this could be crucial to the UK’s ecological make-up, given the significance that the heavily-studied butterfly has on our understanding of many other parts of nature.
Butterflies are very sensitive to environmental changes, meaning they can be effective indicators of the impact on other species that play important roles in our society.
“They can be a canary in a coal mine, if you will,” said Oliver, who fears that his discovery of one-fifth of butterflies suffering may be translated across other species like bees, beetles and earthworms.
“These species provide important functions,” he said, “pollination of crops in wildflowers, pest control, control of disease vectors, helping to decompose waste. These underpin the well-being and health of humans. We should be really alarmed.”
Conservation of creatures large and small is gaining political traction. In the US there’s actually a “butterfly highway” project, with plans to establish a 1,500-mile corridor of vegetation between Mexico and Minnesota for the creatures. Bumblebees, too, are threatened.
The six butterfly species under threat in the UK are the Ringlet, via Tim Alps on Flickr:
The Speckled Wood, via JP Freethinker on Flickr:
The Large White (Cabbage) via Marjan Kustera on Flickr:
And the Large Skipper, via Vicki DeLoach on Flickr:
Main image via Shutterstock