A new study shows that butterfly populations do not thrive in warm, arid environments when climate change is quick. Using records from the last big heat wave in the UK, scientists predict extinction for butterflies in the near future. Climatic extremes are what matter here. Using the UK Butterfly Monitoring Scheme (UKBMS), researchers have assessed 28 species decline in an extreme drought event in the year 1995. If heat should rise this way again, many butterflies won't be long for this world.