Two articles in the Guardian/Observer this weekend seem to have stretched reports produced by conservationists to effect the maximum possible alarm.
On Saturday, the Guardian reported that the National Trust had produced an audit of climate change effects on wildlife in the UK.
British wildlife may not survive third wet summer, warns National Trust
A third miserable summer in parts of the UK could spell disaster for many species of insects, bird life and mammals, the National Trust warns today.
The charity says three wet summers in a row in many regions could mean that creatures – ranging from crane flies (often called daddy-long-legs) to species of butterflies, members of the tit family, puffins and bats – may struggle to survive in some places.
Matthew Oates, a nature conservation adviser for the trust, said: “After two very poor years in a row we desperately need a good summer in 2009 – otherwise it’s going to look increasingly grim for a wealth of wildlife in the UK.
“Climate change is not some future prediction of what might happen. It’s happening now and having a serious impact on our countryside every year.”
The warning comes in a yearly audit produced by the National Trust of how the weather in 2008 affected wildlife.
The year began curiously, according to the audit, with sightings of red admiral butterflies and white-tailed bumblebees in January and February. Many naturalists think it is probably a bad idea for such creatures to be out and about so early. The bees were badly hit by snow and frost in April.
As we reported at the time, it is not unusual to see red admiral butterflies in January. According to the audit “snowdrops and crocuses emerge earlier than normal” in January. But as we also reported, the timing of snowdrops is determined not by the prevailing conditions of the winter, but of the previous Autumn. As for bees, the Natural History Museum website informs us,
In towns and cities in the south [the white tailed bumble bee] commonly continues to forage through the winter where suitable flower resources are available.
Heavy rain during mid-May meant hard times for early-summer insects, which in turn meant many blue tit and great tit nests failed. In June, coastal birds such as choughs, kittiwakes and razorbills bred late and reared few young. In July, puffin numbers on the Farne Islands were down 35% in five years.
The audit printed in the Guardian echoes the article:
• Heavy rain makes life hard for early-summer insects, such as the marsh fritillary butterfly.
• Many nests fail, including those of great and blue tits [...], due to the lack of insects and foul weather.
Heavy rain in May? Not according to the UK’s Met Office, who report that rainfall in May across the UK was just 73% of average. In England, it was higher at 109%, and Southern England it was up still at 145%. This was a local effect. And an increase of 45% is not what you’d call ‘heavy rain’.
The audit continues to say of June that it was a “poor summer for insects such as butterflies, moths, hoverflies, ladybirds and dragonflies”. But the Met Office says that June was 0.4 degrees warmer than average for Southern England, and similar throughout the rest of the UK. The month brought an entirely average amount of sunshine, and less than average rainfall for the South (78%), and slightly above average (110%) for the UK. How can an average month be a poor summer for insects?
On to August. The audit claims
• Few wasps around as the poor weather hinders nest building.
• Two types of cabbage white butterfly, the large white and small white, are unusually plentiful as their predators are depleted by poor weather.
• Crickets and grasshoppers scarcely sing all month. Bats’ staple food, insects, are seriously affected by the heavy rain.
August was a disappointing month. But the Met Office shows that the UK experienced just 54% more rainfall than ‘usual’. This might mean nothing more than it rained one day out of every two more than it would ‘normally’. The UK average rainfall for August is around 90mm. It got 140mm. That makes for a boring Summer, but it’s no torrent of biblical proportions. Hardly a harbinger of doom in a series which is just 31 days long. There were also significant regional differences. Northern Ireland, for example, saw 213% of the rain it ‘usually’ gets according to the MO’s climate statistics. The South of England saw 152%, but the South East (part of the South) saw 125%, while the South West (also part of the South) got 171%. Temperatures in all regions were above average. The only remarkable thing was that it was the ‘dullest’ August in the record, since 1929 at 67% of normal, or 115 hours of sunshine. It is fair to say then, that it was a cloudy August, but that’s not consistent with any observable trend, or change that can be attributed to ‘climate change’ or ‘global warming’.
As a graph comparing the August sunshine, temperature and rainfall anomalies in England over the last century shows, August 2008 is generally unremarkable. In fact, looking at this graph, it’s hard to say anything about England’s climate that would be consistent with the claims that it is changing, or becoming hostile to wildlife – it is a very variable graph. So it’s even harder to know what Matthew Oates, a nature conservation adviser for the National Trust means when he says,
Climate change is not some future prediction of what might happen. It’s happening now and having a serious impact on our countryside every year.
In what way is climate change happening now? And how can it be having an effect on our countryside?
On Sunday, the Guardian’s Sunday paper, the Observer, ran a similar story. [http://www.guardian.co.uk/environment/2008/dec/28/wildlife-animals-conservation]
Third of Britain’s mammals ‘at risk’
Oh No! We’re mammals!
Climate change and habitat loss have led to a dramatic increase in the number of mammals whose future survival is a cause for concern among conservationists, the study commissioned by the People’s Trust for Endangered Species concludes. The Bechstein’s bat, one of the country’s rarest mammals, has shown a marked decline while the number of soprano pipistrelle bats has fallen by 46% in six years.
A visit to the People’s Trust for Endangered Species (PTES) website doesn’t lead us to this study. They don’t seem to have published it yet. Which is odd, isn’t it, given the dramatic headlines it has generated. We’ll try and get hold of it. Meanwhile, the Observer article continues,
Unpredictable and extreme weather conditions, combined with hotter, drier summers and wetter winters, were causing changes in the distribution and behaviour of some species, such as the hazel dormouse, the study finds.
‘Unpredictable and extreme weather conditions’? Does this mean that the poor bats and mice have declined in numbers because they got caught in a rainstorm they weren’t ‘expecting’? What does ‘unpredictability’ have to do with population decline? And when was UK weather ever ‘predictable’? As the graph above shows, there is a great deal of variation in England’s weather. But ‘extreme’ it has not been.
We hear a lot about hotter, drier summers, and wetter winters. But how true are the claims made about them? We took the statistics generously supplied by the Met Office, and put them into Excel. The following graph compares temperatures for each season in England, between 1915 and 2007, with 10 year moving averages.
What strikes first is that it isn’t the Summer in England which shows the greatest change, but the other three seasons. There is a fairly substantial year-to-year variation of average temperature. If the moving average represents a trend, it doesn’t lead to anything we could safely regard as ‘extreme’.
Spring and Autumn exhibit much more significant recent warming trends, which might lead us to imagine that they could represent ‘extremes’. Except that, as transitions between states, they cannot be ‘extreme’ any more than a middle can be an end.
Winters look as though they may have been getting warmer recently, but by the standards of Winters in the 1920-30s, they look fairly normal, having gotten colder between 1930 and the 1970s, then warming up again.
Next, we looked at the amount of rainfall in the winter and summer.
Winters have been getting wetter, according to the moving average. But there is also a great deal of variation. So it is hard to imagine what recent ‘extremes’ would would consist of. It could be said that wetter summers were getting slightly more frequent, but again, in what sense does this constitute ‘extreme’ weather, rather than more frequently ‘slightly worse than mild’? And what does it say about the claim that summers have been getting drier?
Summers since 1980 have not been getting any drier, according to the moving average. They did get drier in the ’70s and ’80s. Clearly, then, there is no substance to the claim that England is experiencing drier summers because of climate change.
So, England’s climate is no less ‘predictable’ than it ever has been. It is no more ‘extreme’ than it ever has been. Winters have been getting slightly wetter, and the summers slightly warmer. But it would be an over statement to say they are getting ‘hotter’.
Back to the animals. We were wondering at this point: fluffy creatures don’t live in abstract climates such as ‘the south’ of England, so what sense does it make to use data about the whole of England, or large parts of it? If we want to know why, or how, animals have responded to climate in a given area, there is little point in looking at aggregate data – averages of averages of averages. Whether or not global warming is happening, the effects that local populations will experience are local. We ought to look at data from a single station. After all, the Guardian’s article explained…
The weather was not terrible across the country all year – some areas such as the north-west, Northern Ireland and parts of Scotland got some rather good conditions. But in places such as the Cotswolds and parts of the Thames Valley and south-east, Oates said there was an awful lot of very bad weather for wildlife.
It is the cumulative effect of bad weather that can be so damaging. If there is one poor summer a species might be lost from a parish here and there. If there are two, the loss is likely to be across two or three parishes. But if there are three consecutive washouts, whole counties could lose species.
(Notice that according to the article, Northern Ireland ‘got some rather good conditions’. But according to the Met Office, it got 213% of the rainfall it normally gets in August, while the Thames Valley was characterised as having ‘ awful lot of very bad weather’ and only got 125%. This makes no sense whatsoever.)
We decided to look at the data from one station near the locations mentioned in the quote above: Oxford. Oxford is just beyond the edge of the Cotswolds, in the Thames Valley, and in the South East. We should be able to see something in the data from this station, which might explain why things are getting hard for wild animals there.
First, rain. Have winters been getting either wetter or drier for animals in Oxford?
Not much. And certainly no where near as much as in the early part of the last century. But the bunny rabbits, the dormice, and all things great and small survived. So how about the summers – has there been any recent change in Oxford’s summer rain?
Curiously, it seems that ‘climate change’ has brought some stability to the levels of rain in Oxford since about 1980.
From now on, said director-general Fiona Reynolds, the trust will advise people how to adapt their lifestyles to climate change and challenge government to be more ecologically aware. “If we think that public policy is not right, then we will say so.”
When we spoke to the National Trust about their ‘audit’, we were expecting to be pointed to a long dry, boring document of facts and figures. But no such research existed”It’s on our website” they said, and it was fairly similar to the one printed in the Guardian. It seems that there’s a reluctance to challenge statements issued by organisations such as the National Trust, and an inclination to turn them into dramatic headlines.