Researchers in Melbourne, Australia have evidence linking earlier butterfly emergence to climate change. The report in Science daily linked observational data with laboratory data on the Common Brown butterfly (Heteronympha merope).
"Butterflies are emerging in spring over 10 days earlier than they did 65 years ago, a shift that has been linked to regional human-induced climate change in a University of Melbourne- led study. The work reveals, for the first time, a causal link between increasing greenhouse gases, regional warming and the change in timing of a natural event".
"The team raised caterpillars of the Common Brown Butterfly in the laboratory to measure the physiological impact of temperature on its rate of development. They used this information to model the effect of observed historical climate trends in Melbourne on the speed of the butterfly's development. They combined this with global climate model outputs for the Melbourne area over the same period to examine whether natural climate variability or human influence on climate was more likely to have caused the air temperature change seen in Melbourne."You can read the whole story at Science Daily.