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.


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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Like it or hate it, it doesn't matter: Brexit is happening, and we've got to make a success of it

It's time to stop complaining and start campaigning, says Stella Creasy.

A shortage of Marmite, arguments over exporting jam and angry Belgians. And that’s just this month.  As the Canadian trade deal stalls, and the government decides which cottage industry its will pick next as saviour for the nation, the British people are still no clearer getting an answer to what Brexit actually means. And they are also no clearer as to how they can have a say in how that question is answered.

To date there have been three stages to Brexit. The first was ideological: an ever-rising euroscepticism, rooted in a feeling that the costs the compromises working with others require were not comparable to the benefits. It oozed out, almost unnoticed, from its dormant home deep in the Labour left and the Tory right, stoked by Ukip to devastating effect.

The second stage was the campaign of that referendum itself: a focus on immigration over-riding a wider debate about free trade, and underpinned by the tempting and vague claim that, in an unstable, unfair world, control could be taken back. With any deal dependent on the agreement of twenty eight other countries, it has already proved a hollow victory.

For the last few months, these consequences of these two stages have dominated discussion, generating heat, but not light about what happens next. Neither has anything helped to bring back together those who feel their lives are increasingly at the mercy of a political and economic elite and those who fear Britain is retreating from being a world leader to a back water.

Little wonder the analogy most commonly and easily reached for by commentators has been that of a divorce. They speculate our coming separation from our EU partners is going to be messy, combative and rancorous. Trash talk from some - including those in charge of negotiating -  further feeds this perception. That’s why it is time for all sides to push onto Brexit part three: the practical stage. How and when is it actually going to happen?

A more constructive framework to use than marriage is one of a changing business, rather than a changing relationship. Whatever the solid economic benefits of EU membership, the British people decided the social and democratic costs had become too great. So now we must adapt.

Brexit should be as much about innovating in what we make and create as it is about seeking to renew our trading deals with the world. New products must be sought alongside new markets. This doesn’t have to mean cutting corners or cutting jobs, but it does mean being prepared to learn new skills and invest in helping those in industries that are struggling to make this leap to move on. The UK has an incredible and varied set of services and products to offer the world, but will need to focus on what we do well and uniquely here to thrive. This is easier said than done, but can also offer hope. Specialising and skilling up also means we can resist those who want us to jettison hard-won environmental and social protections as an alternative. 

Most accept such a transition will take time. But what is contested is that it will require openness. However, handing the public a done deal - however well mediated - will do little to address the division within our country. Ensuring the best deal in a way that can garner the public support it needs to work requires strong feedback channels. That is why transparency about the government's plans for Brexit is so important. Of course, a balance needs to be struck with the need to protect negotiating positions, but scrutiny by parliament- and by extension the public- will be vital. With so many differing factors at stake and choices to be made, MPs have to be able and willing to bring their constituents into the discussion not just about what Brexit actually entails, but also what kind of country Britain will be during and after the result - and their role in making it happen. 

Those who want to claim the engagement of parliament and the public undermines the referendum result are still in stages one and two of this debate, looking for someone to blame for past injustices, not building a better future for all. Our Marmite may be safe for the moment, but Brexit can’t remain a love it or hate it phenomenon. It’s time for everyone to get practical.