Butterfly effects

Under such headlines as ‘British butterfly defies doom prediction to thrive in changing climate’, the usual suspects (e.g. the Guardian and the Independent) recently publicised a study claiming that, thanks to global warming, ‘a once-rare British butterfly’, the Brown Argus, ‘is becoming a common sight in the English countryside’. A paper from York University, it was reported, showed that these butterflies have moved so far north that they can now be seen ‘within a few miles’ of York. Not for the first time on reading similar claims, I wondered how it is that their authors seem to know so little about butterflies, My battered copy of the best book on British butterflies I know, published by Edmund Sandars in 1939, confirmed that 70 years ago the Brown Argus was found throughout Britain ‘as far north as Aberdeen’.

Attempts to use butterflies as evidence of global warming are popular with newspapers because it gives them an excuse to decorate their pages with pictures of our most colourful insects — although in the years when the warming scare was at its height, these more usually accompanied predictions that climate change was threatening them with extinction.