A Guardian article today leaves me frustrated and bemused (as is so often the case with articles in the Guardian whenever there is a connection, however, tenuous, with climate change). Its main headline suggests good news: “Midsummer butterflies spotted early in Britain after sunny spring” but its secondary headline suggests bad news: “Scientists fear early emerging insects may fall out of sync with pathogens, predators or availability of food”.

The article itself opens with good news: “Midsummer butterflies are on the wing in early May after a sunny spring prompted one of the most advanced seasons for Britain’s Lepidoptera on record.”

But there’s also bad news: “Last year was the second worst for common butterflies since scientific monitoring began 50 years ago” followed by more good news:

…butterfly experts are hoping that the sunny spring enables populations to recover some of their numbers.

“It’s been a wonderful spring for butterflies in Scotland,” said Prescott. “The butterflies are on the wing much longer and many species are moving north rapidly.”

That sounds pretty reassuring after last year’s dreadful statistics. But wait a minute – there’s more bad news: “While some species appear to be adapting their lifecycles to climatic changes, there are fears some early emerging insects may fall out of sync with pathogens, predators or the availability of food for their caterpillars.”

And of course we have to be worried about climate change: “Lepidopterists said the early appearances this year were caused by the prolonged sunny, dry spring but were also a clear sign of insects responding to global heating.” [My emphasis].

One sunny spring? Really? Global heating? Or just weather? Thirteen years ago, reflecting on the mixed weather in spring 2012, the Guardian made it clear that cold and wet weather are bad for butterflies:

…Some spring species emerged several weeks early in March, but the wettest April on record and the continuing rain this month has delayed the appearance of many butterflies.

And wildlife charity Butterfly Conservation is warning that if the wet conditions continue it could affect the breeding success of some species later in the year.

Cold, wet weather makes butterflies less active, reducing feeding and mating….

As for climate versus weather, it looked like weather was the predominant factor then, as I suspect it is now:

He [Richard Fox, Butterfly Conservation surveys manager] added: “Last year we had a hot spring and a poor summer. This year we’re having a poor spring, so let’s hope the summer is better.”

Speaking of the charity Butterfly Conservation, I thought I would take a look at their website, and in particular an article about the long-term decline of UK butterfly species. Unfortunately, this falls foul of the issue I complained of in Climate Change Ate My Homework, namely throwing climate change in as a makeweight with a load of other factors, while failing to assess the significance of each factor. Thus (Dr Richard Fox again):

I am devastated by the decline of our beloved British butterflies, and I’m sorry to say it has been brought about by human actions: we have destroyed wildlife habitats, polluted the environment, used pesticides on an industrial scale and we are changing the climate.

Destroyed habitats, polluted environment, industrial scale pesticide use….but climate change.

That means that when we have poor weather, these already-depleted butterfly populations are highly vulnerable and can’t bounce back like they once did – and with climate change, that unusual weather is becoming more and more usual.

Is it? Really? In the UK the weather has always involved extremes. Hot, cold, wet, dry, stormy, anticyclonic periods of calm – none of these things are new or unusual. They are just UK weather. And while weather from season to season and from year to year is clearly an influential factor in the success or failure of butterflies, nevertheless, according to Butterfly Conservation’s article, the problem appears to be predominantly habitat loss:

These species all require specific habitat to thrive, and those habitats have been destroyed over the past century.…

…By far the best thing we can do to help butterflies is to create more habitat. Last year we published research which showed that letting parts of your garden grow wild with long grass increases the number and variety of butterflies that you see. That is why we are calling on people and councils across the UK to pledge to not cut their grass this year from April to September: this simple act can make a real, immediate difference to butterflies, moths and other wildlife…

Returning to today’s Guardian article, interestingly Dr Fox also notes that evolutionary factors can help:

If the weather has tricked some into coming out too early it should not be a disaster. There should also be plenty of scope for evolutionary adaptation.

It’s clearly a very complicated subject, one worthy of more thoughtful and detailed analysis than scare-mongering about climate change in the context of weather variation from year to year. I prefer to celebrate the good news both for myself and for butterflies: a dry, sunny spring this year, as opposed to last year’s wet and miserable one, which, where I live, continued damp and cool through the summer.