Posted by admin at 1:25 PM Thursday, April 8, 2010
One of the biggest challenges for climate change scientists is pinpointing direct evidence of disturbing changes in the global climate. In Australia, however, a small but significant shift in the timing of spring events may be the place to start. In the last 65 years, a striking increase of 0.14 degrees Celsius in air temperature per decade has taken place in Melbourne. On top of this, scientists at the University of Melbourne have discovered a biological change in the common butterfly Heteronympha merope: the butterfly is emerging from its cocoon 1.6 days early each decade over the same 65 year period.
Butterflies raised in the laboratory with a controlled climate mirroring the rise in Melbourne’s temperature also revealed a shift in the timing of the butterflies’ emergence from the chrysalis (1.3 days earlier). Furthermore, there is strong evidence that the actual 0.14 degree increase in temperature measured in Melbourne is the result of human activity and cannot be explained but natural variations in temperature over time (1). The evidence for the human-induced climate change only grows harder and harder to ignore.