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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Theresa May could live to regret not putting Article 50 to a vote sooner

Today's Morning Call.

Theresa May will reveal her plan to Parliament, Downing Street has confirmed. They will seek to amend Labour's motion on Article 50 adding a note of support for the principle of triggering Article 50 by March 2017, in a bid to flush out the diehard Remainers.

Has the PM retreated under heavy fire or pulled off a clever gambit to take the wind out of Labour's sails while keeping her Brexit deal close to her chest? 

Well, as ever, you pays your money and you makes your choice. "May forced to reveal Brexit plan to head off Tory revolt" is the Guardian's splash. "PM caves in on plans for Brexit" is the i's take. "May goes into battle for Brexit" is the Telegraph's, while Ukip's Pravda aka the Express goes for "MPs to vote on EU exit today".

Who's right? Well, it's a bit of both. That the government has only conceded to reveal "a plan" might mean further banalities on a par with the PM's one-liner yesterday that she was seeking a "red white and blue Brexit" ie a special British deal. And they've been aided by a rare error by Labour's new star signing Keir Starmer. Hindsight is 20:20, but if he'd demanded a full-blown white paper the government would be in a trickier spot now. 

But make no mistake: the PM didn't want to be here. It's worth noting that if she had submitted Article 50 to a parliamentary vote at the start of the parliamentary year, when Labour's frontbench was still cobbled together from scotch-tape and Paul Flynn and the only opposition MP seemed to be Nicky Morgan, she'd have passed it by now - or, better still for the Tory party, she'd be in possession of a perfect excuse to reestablish the Conservative majority in the House of Lords. May's caution made her PM while her more reckless colleagues detonated - but she may have cause to regret her caution over the coming months and years.

PANNICK! AT THE SUPREME COURT

David Pannick, Gina Miller's barrister, has told the Supreme Court that it would be "quite extraordinary" if the government's case were upheld, as it would mean ministers could use prerogative powers to reduce a swathe of rights without parliamentary appeal. The case hinges on the question of whether or not triggering Article 50 represents a loss of rights, something only the legislature can do.  Jane Croft has the details in the FT 

SOMETHING OF A GAMBLE

Ministers are contemplating doing a deal with Nicola Sturgeon that would allow her to hold a second independence referendum, but only after Brexit is completed, Lindsay McIntosh reports in the Times. The right to hold a referendum is a reserved power. 

A BURKISH MOVE

Angela Merkel told a cheering crowd at the CDU conference that, where possible, the full-face veil should be banned in Germany. Although the remarks are being widely reported in the British press as a "U-Turn", Merkel has previously said the face veil is incompatible with integration and has called from them to be banned "where possible". In a boost for the Chancellor, Merkel was re-elected as party chairman with 89.5 per cent of the vote. Stefan Wagstyl has the story in the FT.

SOMEWHERE A CLOCK IS TICKING

Michael Barnier, the EU's chief Brexit negotiator, has reminded the United Kingdom that they will have just 15 to 18 months to negotiate the terms of exit when Article 50 is triggered, as the remaining time will be needed for the deal to secure legislative appeal.

LEN'S LAST STAND?

Len McCluskey has quit as general secretary of Unite in order to run for a third term, triggering a power struggle with big consequences for the Labour party. Though he starts as the frontrunner, he is more vulnerable now than he was in 2013. I write on his chances and possible opposition here.

AND NOW FOR SOMETHING COMPLETELY DIFFERENT

Emad asks if One Night Stand provides the most compelling account of sex and relationships in video games yet.

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Theresa May risks becoming an accidental Europe wrecker, says Rafael Behr

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Stephen Bush is special correspondent at the New Statesman. His daily briefing, Morning Call, provides a quick and essential guide to British politics.