In a recent post, Troppo’s Ken Parish suggested that quality newspapers serve a gatekeeping role, ensuring "at least some measure of quality assurance". So what’s happening at the Australian?
In a recent piece on wind farms, environment editor Graham Lloyd attempted to explain how wind turbines kill birds and why wind farms can’t be built close to airfields:
There is a common misconception that birds are sliced up by wind turbine blades, which appear to be spinning slowly but are actually travelling at speeds of up to 200km at the tip. In fact, birds die when they encounter the windshear and pressure changes caused by banks of wind turbines churning up the air. They literally pop and fall out of the sky. This is why there is a ban on wind farms being built near airfields, lest light aircraft pilots meet the same fate.
Lloyd seems a little confused. While there is some evidence that bats can be killed by a sudden drop in pressure caused by flying too close to the tips of a turbine’s blades, this isn’t how most birds are killed. Birds typically die after colliding with blades.
A study by Erin Baerwald, Genevieve D’Amours, Brandon Klug and Robert Barclay (pdf), reported that "Even if echolocation allows bats to detect and avoid turbine blades, they may be incapacitated or killed by internal injuries caused by rapid pressure reductions they can not detect." These pressure changes cause air in the bats’ lungs to expand leading the small blood vessels around the edges of the lungs to burst — a process known as barotrauma. But according to the researchers:
Birds are also killed at wind turbines, but at most wind energy facilities fewer birds than bats are killed, and barotrauma has not been suggested as a cause of bird fatalities.
As for the idea that pressure changes will cause light aircraft pilots to fall out of the sky like bats, this seems unlikely. According to Baerwald, the zone around the blade tips in which pressure suddenly drops is only a metre or so in diameter. The major reason wind farms aren’t allowed near airfields is because pilots might fly into them — especially at night.