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 Images
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The Fire Brigades Union reaffiliates to Labour - what does it mean?

Any union rejoining Labour will be welcomed by most in the party - but the impact on the party's internal politics will be smaller than you think.

The Fire Brigades Union (FBU) has voted to reaffiliate to the Labour party, in what is seen as a boost to Jeremy Corbyn. What does it mean for Labour’s internal politics?

Firstly, technically, the FBU has never affliated before as they are notionally part of the civil service - however, following the firefighters' strike in 2004, they decisively broke with Labour.

The main impact will be felt on the floor of Labour party conference. Although the FBU’s membership – at around 38,000 – is too small to have a material effect on the outcome of votes themselves, it will change the tenor of the motions put before party conference.

The FBU’s leadership is not only to the left of most unions in the Trades Union Congress (TUC), it is more inclined to bring motions relating to foreign affairs than other unions with similar politics (it is more internationalist in focus than, say, the PCS, another union that may affiliate due to Corbyn’s leadership). Motions on Israel/Palestine, the nuclear deterrent, and other issues, will find more support from FBU delegates than it has from other affiliated trade unions.

In terms of the balance of power between the affiliated unions themselves, the FBU’s re-entry into Labour politics is unlikely to be much of a gamechanger. Trade union positions, elected by trade union delegates at conference, are unlikely to be moved leftwards by the reaffiliation of the FBU. Unite, the GMB, Unison and Usdaw are all large enough to all-but-guarantee themselves a seat around the NEC. Community, a small centrist union, has already lost its place on the NEC in favour of the bakers’ union, which is more aligned to Tom Watson than Jeremy Corbyn.

Matt Wrack, the FBU’s General Secretary, will be a genuine ally to Corbyn and John McDonnell. Len McCluskey and Dave Prentis were both bounced into endorsing Corbyn by their executives and did so less than wholeheartedly. Tim Roache, the newly-elected General Secretary of the GMB, has publicly supported Corbyn but is seen as a more moderate voice at the TUC. Only Dave Ward of the Communication Workers’ Union, who lent staff and resources to both Corbyn’s campaign team and to the parliamentary staff of Corbyn and McDonnell, is truly on side.

The impact of reaffiliation may be felt more keenly in local parties. The FBU’s membership looks small in real terms compared Unite and Unison have memberships of over a million, while the GMB and Usdaw are around the half-a-million mark, but is much more impressive when you consider that there are just 48,000 firefighters in Britain. This may make them more likely to participate in internal elections than other affiliated trade unionists, just 60,000 of whom voted in the Labour leadership election in 2015. However, it is worth noting that it is statistically unlikely most firefighters are Corbynites - those that are will mostly have already joined themselves. The affiliation, while a morale boost for many in the Labour party, is unlikely to prove as significant to the direction of the party as the outcome of Unison’s general secretary election or the struggle for power at the top of Unite in 2018. 

Stephen Bush is editor of the Staggers, the New Statesman’s political blog.