Widespread drought-sensitive butterfly population extinctions could occur in the UK as early as 2050 according to a new study produced by government advisors.

The study, published in the scientific journal Nature Climate Change and conducted by scientists from Natural England, the Centre for Ecology and Hydrology (CEH), and Exeter University, warns that droughts could compound other threats the insects face. However, authors said that substantial greenhouse gas emission reductions and better management of landscapes (to connect fragmented habitats) could buy more time for the butterflies that stand to be affected.

The study’s lead author Dr Tom Oliver from the Centre for Ecology & Hydrology said, “The results are worrying. Until I started this research, I hadn’t quite realised the magnitude and potential impacts from climate change. For drought-sensitive butterflies, and potentially other [creatures], widespread population extinctions are expected by 2050. To limit these loses, both habitat restoration and reducing CO2 emissions have a role. In fact, a combination of both is necessary.”

The team identified six species of drought-sensitive butterfly - ringlet, speckled wood, large skipper, large white, small white and green-veined white - as having a low probability of survival by mid-century, even under most favourable emissions scenario. Butterflies were chosen for the research as they are amongst the best studied groups of species, with good records of year-to-year changes in abundance; the team used data on 28 species of butterfly collected from 129 sites.

Dr Oliver added, “Losses are likely to be more severe in drier areas with more intensive land use, whilst wetter areas with less fragmented habitat will provide refugia. We assume that butterflies won’t have time to evolve to become more drought-tolerant, because their populations are already small, and evolution would need to be very rapid. The study looked at butterflies but the conclusions are potentially valid for other species such as birds, beetles, moths and dragonflies.”

Climate change is predicted to bring warmer and changing rainfall patterns (projections are for more rain, falling less often but in heavier deluges), which will increase the risk of drought in the South-East in particular.

On a more positive note, the authors did suggest that moves to improve conservation and protect the variety and interconnection of habitats in the UK are likely to yield benefits for threatened butterfly species. Commenting on the findings, Tom Brereton from Butterfly Conservation said, “The study highlights the pressing need to investigate local conservation measures that may help drought-sensitive butterflies to adapt and persist in our changing countryside.”

Though butterflies have been studied in more depth than most creatures, the scientists warned that there is reason to believe other drought sensitive species will be similarly affected by climate change. The study’s authors also noted that the most at-risk species are only likely to survive if serious cuts in carbon emissions are achieved, and soon.

Watch CEH's Dr Tom Oliver explain the study's findings in the video below: