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.

Photo: Getty
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Theresa May's "clean Brexit" is hard Brexit with better PR

The Prime Minister's objectives point to the hardest of exits from the European Union. 

Theresa May will outline her approach to Britain’s Brexit deal in a much-hyped speech later today, with a 12-point plan for Brexit.

The headlines: her vow that Britain will not be “half in, half out” and border control will come before our membership of the single market.

And the PM will unveil a new flavour of Brexit: not hard, not soft, but “clean” aka hard but with better PR.

“Britain's clean break from EU” is the i’s splash, “My 12-point plan for Brexit” is the Telegraph’s, “We Will Get Clean Break From EU” cheers the Express, “Theresa’s New Free Britain” roars the Mail, “May: We’ll Go It Alone With CLEAN Brexit” is the Metro’s take. The Guardian goes for the somewhat more subdued “May rules out UK staying in single market” as their splash while the Sun opts for “Great Brexpectations”.

You might, at this point, be grappling with a sense of déjà vu. May’s new approach to the Brexit talks is pretty much what you’d expect from what she’s said since getting the keys to Downing Street, as I wrote back in October. Neither of her stated red lines, on border control or freeing British law from the European Court of Justice, can be met without taking Britain out of the single market aka a hard Brexit in old money.

What is new is the language on the customs union, the only area where May has actually been sparing on detail. The speech will make it clear that after Brexit, Britain will want to strike its own trade deals, which means that either an unlikely exemption will be carved out, or, more likely, that the United Kingdom will be out of the European Union, the single market and the customs union.

(As an aside, another good steer about the customs union can be found in today’s row between Boris Johnson and the other foreign ministers of the EU27. He is under fire for vetoing an EU statement in support of a two-state solution, reputedly to curry favour with Donald Trump. It would be strange if Downing Street was shredding decades of British policy on the Middle East to appease the President-Elect if we weren’t going to leave the customs union in order at the end of it.)

But what really matters isn’t what May says today but what happens around Europe over the next few months. Donald Trump’s attacks on the EU and Nato yesterday will increase the incentive on the part of the EU27 to put securing the political project front-and-centre in the Brexit talks, making a good deal for Britain significantly less likely.

Add that to the unforced errors on the part of the British government, like Amber Rudd’s wheeze to compile lists of foreign workers, and the diplomatic situation is not what you would wish to secure the best Brexit deal, to put it mildly.

Clean Brexit? Nah. It’s going to get messy. 

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