Is wind-farm bat kill an urban myth?

Who knows why I got interested? I don’t read James Delingpole, because frankly the guy’s a dill. On the spectrum of “dills who are climate deniers”, his name appears near the “you’re a dill for even wondering what this dill says” end of the scale.

But for some reason I did, and therefore for some reason I came across his obsession about bats being killed by their “lungs imploding” because of air pressure around wind farms.

OK, at first glance, the Mythbusters would start at “plausible”. Barotrauma – the scientific term, which you use if you’re not apparently writing for an audience of idiots who’ll switch off even if you provide the definition in the third par – can happen even to mammals as big as humans, if (for example) we break the rules when diving.

Delingpole avoids the scientific term, either because (a) his science would fit in a matchbox without removing the matches, or (b) he’s a cynical dead shit who’s trying to snow-job readers who don’t do science. Take your pick

Bats are smaller than people, wind farms generate pressure differences, QED bats flying through wind turbine turbulence could die from barotrauma. Or, in the condescending “I know more than you but let’s use small words For the Dummies” tone of Delingpole, their “lungs implode”.

I wish I didn’t obsess about such things, I really do, but after a bit of a trawl through the scholarship, on a Saturday night why-do-I-do-this: it’s probably not true.

The whole “wind turbines kill bats through barotrauma” thing seems to arise from just one paper – this one: http://www.sciencedirect.com/science/article/pii/S0960982208007513

Now, there are some problems with the paper that seems to form the entire scholarly basis for Deligpole’s obsession about barotrauma killing bats around wind farms.

The first is entirely my own work: the number of bats the author says was killed in a single night (188 victims): because by the time the research reached Scientific American, the timeline had stretched to “between July and September”. http://www.scientificamerican.com/article.cfm?id=wind-turbines-kill-bats

Hmm.

That’s significantly more dead bats than any other research identified. For example, this http://asmjournals.org/doi/abs/10.1644/10-MAMM-A-404.1 article in Europe said bats are being killed at “unprecedented rates” when the number – without a timeframe in the abstract, and I don’t get paid for this blog, so I didn’t buy the article – yielded a sample of 39 dead bats.

Yes, species, geography and season will impact the numbers, but going from 188 bats in one night, to 188 bats over some months, to 39 dead bats over any unspecified time-frame being “unprecedented” – that should give rise to questions, at least.

Here’s another contradictory number: http://www.bioone.org/doi/abs/10.3161/150811010X537846 - which says wind farms in the area of the study kill 20 bats each year.

Now to the substance of the issue.

From – as far as I can find – one paper originating the idea of barotrauma, from which all else have followed, Delingpole has formed an urban mythology that wind farms make bats implode.

Bullshit.

This study - http://vet.sagepub.com/content/49/2/362.short - gives barotrauma as a very minor cause of death, comparing dead bats around turbines to dead bats in cities. It also notes that freezing specimens will give misleading results, because frozen cells (for example in the lungs) look a lot like pre-mortem barotrauma.

Bats die because, like birds, they fly into large structures (their sonar, after all, is attuned not to a skyscraper, but to hunting insects).

The foundation of “bat barotrauma” comes from one, single, and as far as I can tell, un-replicated study.

But we all know about cherry-picking the science, don’t we?

Misrepresenting Antarctic ice and climate change

Tim Lambert over at the Deltoid blog would probably be better at this, but he’s been quiet lately and I have a few minutes to spare, while I wait for a university to answer my call.

The Australian, courtesy of Graham Lloyd, is running with the old “what about Antarctic sea ice? Huh? Huh?” line, here. As is noted all over the world, at a time when Arctic sea ice has shrunk dramatically, there has been an increase in the sea ice down around the Antarctic.

And because there are still people in the world who want to muddy the climate change waters, the Antarctic is now becoming the poster-child for the denialist mentality.

So I guess I may as well spend a few minutes on the issue. I’m not going to refute The Australian point-by-point, but here are details to keep in mind when skeptics roll out the “Antarctic sea ice growing” argument.

      1. Most of the Antarctic’s ice is on land, not sea – and the land ice extent is shrinking, because the southern land ice loss is greater than the sea ice gain (source: http://www.skepticalscience.com/antarctica-gaining-ice.htm).

2    2. Sea ice formation in the Antarctic is being influenced by factors like the ozone hole (which reduces atmospheric temperatures), water freshness (rising, which makes it easier to freeze), winds and so on.

3
3    3. While the extent (ie, the area in square kilometers) of Antarctic sea ice is growing, some research suggests it might be getting thinner (http://www.agu.org/pubs/crossref/2012/2012JC008141.shtml) - so the change in the overall volume of sea ice is much less well understood.

4    4. The Southern Ocean is still warming (http://www.csiro.au/Portals/Media/Deep-Ocean-Warming.aspx).

That should do for now, I suppose …

Can we just forget about the polar bears for a while?

Not that I don’t care, but ever since An Inconvenient Truth made the polar bear the iconic image for climate change, it’s become a distraction from the real debate.

Take this piece of logical legerdemain from Matt Ridley. Admitting through gritted teeth that actually, really, oh-all-right the Arctic sea ice is retreating, he plays a misdirection game: “In the Holocene Optimum there was no collapse of the polar-bear population”.

Keep calm and carry on, people, the polar bears will get by somehow.

That, of course, ignores two itsy-bitsy ever-so-tiny details.

• 1.     Polar bears and arctic foxes are only so-so as a proxy to answer the question “what impact would an ice-free Arctic have on species in the region?” Ridley somehow manages to overlook species, like the muskox and the steppe bison, that may have suffered a population collapse in the Holocene. It’s odd that he’d miss these examples, since he’s a zoologist.

 

• 2.     The survival of the polar bear is not a benchmark for the impact of warming on human society.

Ridley ends with this red herring:

“The sea-dominated Southern Hemisphere is certainly warming more slowly than the land-dominated Northern Hemisphere, but it has still been warming. If warming is supposed to be "global," shouldn't sea ice retreat at both ends of the world?”

That’s a misleading question – since it’s been answered. Ridley seems to be placing a bet that his readers don’t know this. His readers don’t realize that the Antarctic is land, not sea; that the freshening of the Southern Ocean allows it to freeze more readily.

Most importantly, if all of the Antarctic ice is taken into account – both land and sea ice – the Antarctic ice cap, like the Arctic, is shrinking.