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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Voters are turning against Brexit but the Lib Dems aren't benefiting

Labour's pro-Brexit stance is not preventing it from winning the support of Remainers. Will that change?

More than a year after the UK voted for Brexit, there has been little sign of buyer's remorse. The public, including around a third of Remainers, are largely of the view that the government should "get on with it".

But as real wages are squeezed (owing to the Brexit-linked inflationary spike) there are tentative signs that the mood is changing. In the event of a second referendum, an Opinium/Observer poll found, 47 per cent would vote Remain, compared to 44 per cent for Leave. Support for a repeat vote is also increasing. Forty one per cent of the public now favour a second referendum (with 48 per cent opposed), compared to 33 per cent last December. 

The Liberal Democrats have made halting Brexit their raison d'être. But as public opinion turns, there is no sign they are benefiting. Since the election, Vince Cable's party has yet to exceed single figures in the polls, scoring a lowly 6 per cent in the Opinium survey (down from 7.4 per cent at the election). 

What accounts for this disparity? After their near-extinction in 2015, the Lib Dems remain either toxic or irrelevant to many voters. Labour, by contrast, despite its pro-Brexit stance, has hoovered up Remainers (55 per cent back Jeremy Corbyn's party). 

In some cases, this reflects voters' other priorities. Remainers are prepared to support Labour on account of the party's stances on austerity, housing and education. Corbyn, meanwhile, is a eurosceptic whose internationalism and pro-migration reputation endear him to EU supporters. Other Remainers rewarded Labour MPs who voted against Article 50, rebelling against the leadership's stance. 

But the trend also partly reflects ignorance. By saying little on the subject of Brexit, Corbyn and Labour allowed Remainers to assume the best. Though there is little evidence that voters will abandon Corbyn over his EU stance, the potential exists.

For this reason, the proposal of a new party will continue to recur. By challenging Labour over Brexit, without the toxicity of Lib Dems, it would sharpen the choice before voters. Though it would not win an election, a new party could force Corbyn to soften his stance on Brexit or to offer a second referendum (mirroring Ukip's effect on the Conservatives).

The greatest problem for the project is that it lacks support where it counts: among MPs. For reasons of tribalism and strategy, there is no emergent "Gang of Four" ready to helm a new party. In the absence of a new convulsion, the UK may turn against Brexit without the anti-Brexiteers benefiting. 

George Eaton is political editor of the New Statesman.