Wind farms and abuse of statistics: bird edition

When "wind farms are dangerous" really just means "there are a lot of birds".

When dealing with large numbers, it helps to have an idea of the expected order of magnitude. That way, you can know whether it is merely the number which is large, or the thing it's describing as well.

For instance, if I tell you of a country with 140,000 people in long-term unemployment, it's rather important for you to know if I'm talking about the US (population 280 million) or Luxembourg (population 525,000).

That's a test a Spectator article, Wind farms vs wildlife, failed quite badly this week.

The author, Clive Hambler, is a lecturer in biological and human sciences at Oxford university, and quotes a number of statistics to demonstrate how dangerous wind farms are to wildlife. For instance:

Every year in Spain alone — according to research by the conservation group SEO/Birdlife — between 6 and 18 million birds and bats are killed by wind farms. They kill roughly twice as many bats as birds. This breaks down as approximately 110–330 birds per turbine per year and 200–670 bats per year. And these figures may be conservative if you compare them to statistics published in December 2002 by the California Energy Commission: ‘In a summary of avian impacts at wind turbines by Benner et al (1993) bird deaths per turbine per year were as high as 309 in Germany and 895 in Sweden.’

Similar claims are made throughout. Apparently the annual death toll of bats in the US and Canada is "up to three million", "Norwegian wind farms kill over ten white-tailed eagles per year", and so on.

What is missing is any context through which we can examine these numbers. It might change our interpretation of the figures to know that:

Domestic and feral cats have also been considered a major source of anthropogenic-caused mortality with estimates near 100 million annual bird deaths [in the US].

Or that, on roads near wetlands in Canada:

223 birds were killed per mile per year.                                                                                            

Power lines in the US are estimated to kill:

…approximately 130 million birds per year.                                                                                                        

While we're banning things, we may want to keep an eye out for that scourge of the avian world, windows:

97.6 to 976 million bird deaths per year in the U.S. due to collisions with windows… based on an estimated 1 to 10 bird deaths per structure per year from a fatality study in New York.

All those figures come from a 2005 paper by the US Department of Agriculture.

In other words, even with the massive figures from Spain – figures which show deaths per turbine per year two orders of magnitude higher than equivalent figures cited in the above paper, which are based on an assumption that for every confirmed death, there's nineteen uncomfirmed, and which come from a set of guidelines which explicitly concludes wind farms are OK for birds if built correctly (pdf) –  wind farms kill fewer birds than cats, power lines, roads or windows. That comparison would have been rather useful to include in the original piece. With that in mind, the numbers in the piece become less a demonstration of the awesome mortality of wind farms, and more a confirmation that yes, there are a lot of birds in the world.

Update

It's been pointed out on Twitter that I'm not comparing like to like. Spain is smaller than the US, of course. Thankfully, the USDA also estimates the number of birds killed by wind farms in America: between 20,000 and 37,000 a year. I let you draw your own conclusions from the discrepancy.

Wind Turbines in Spain. Photograph: Wikimedia Commons

Alex Hern is a technology reporter for the Guardian. He was formerly staff writer at the New Statesman. You should follow Alex on Twitter.

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I dined behind the Houses of Parliament in my sexually connected foursome

My wife and I would sometimes dine out with another couple. We did not always check the significance of the date. 

I am self-employed and find that working from home, setting your own schedule, the days generally blur into each other, with weekends holding no significance, and public holidays, when those who are employed in factories, offices or shops get time off, meaning nothing. I am often surprised to go out and find the streets empty of traffic because it is some national day of observance, such as Christmas, that I wasn’t aware of. I find myself puzzled as to why the shops are suddenly full of Easter eggs or pancake batter.

Growing up in a Communist household, we had a distinct dislike for this kind of manufactured marketing opportunity anyway. I remember the time my mother tried to make me feel guilty because I’d done nothing for her on Mother’s Day and I pointed out that it was she who had told me that Mother’s Day was a cynical creation of the greetings card monopolies and the floral industrial complex.

Valentine’s Day is one of those I never see coming. It’s the one day of the year when even the worst restaurants are completely booked out by couples attempting to enjoy a romantic evening. Even those old-fashioned cafés you’ll find still lurking behind railway stations and serving spaghetti with bread and butter will tell you there’s a waiting list if you leave it late to reserve a table.

In the late 1980s my wife and I would sometimes dine out with another couple, he a writer and she a TV producer. One particular place we liked was a restaurant attached to a 1930s block of flats, near the Houses of Parliament, where the endless corridors were lined with blank doors, behind which you sensed awful things happened. The steel dining room dotted with potted palm trees overlooked a swimming pool, and this seemed terribly sophisticated to us even if it meant all your overpriced food had a vague taste of chlorine.

The four of us booked to eat there on 14 February, not realising the significance of the date. We found at every other table there was a single couple, either staring adoringly into each other’s eyes or squabbling.

As we sat down I noticed we were getting strange looks from our fellow diners. Some were sort of knowing, prompting smiles and winks; others seemed more outraged. The staff, too, were either simpering or frosty. After a while we realised what was going on: it was Valentine’s Day! All the other customers had assumed that we were a sexually connected foursome who had decided to celebrate our innovative relationship by having dinner together on this special date.

For the four of us, the smirking attention set up a strange dynamic: after that night it always felt like we were saying something seedy to each other. “Do you want to get together on Sunday?” I’d say to one of them on the phone, and then find myself blushing. “I’ll see if we can fit it in,” they’d reply, and we would both giggle nervously.

Things became increasingly awkward between us, until in the end we stopped seeing them completely. 

This article first appeared in the 25 May 2017 issue of the New Statesman, Why Islamic State targets Britain

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