More birds killed by cats than wind turbines
May 9, 2007
Note: NATURE's article was based on flawed data. The journal will publish a correction.
Last week's report by the U.S. National Academy of Sciences (NAS) on the environmental impact of wind farms warned that turbines may kill up to 40,000 birds per year, a toll that makes some question the clean energy source is worth the trouble.
Writing in the current issue of Nature, Emma Marris and Daemon Fairless find that while 40,000 bird deaths may seem high, it's all relative. Domestic cats kill "hundreds of millions" of birds per year.
Marris and Fairless say that more significant concerns are over the number of birds of prey that are whacked each year: in California there are worries about the toll of the Altamont pass wind on golden eagles, while in Spain environmentalists report that 866 griffon vultures have been killed by wind-powered blades since 2000. Still the authors are unsure why wind power has such a bad reputation among the environmentally-inclined.
"For carbon-free power sources, wind turbines have an oddly bad reputation among conservationists," the write.
CITATION: Emma Marris & Daemon Fairless (2007). Wind farms' deadly reputation hard to shift. Nature Volume 447 Number 7141.
Comment from Dan Boone
How embarrassing...the article in Nature (10 May 07 - p. 126) was introduced and built around an erroneous point (i.e., it takes 30 wind turbines to kill one bird each year) which a co-author now-admits was based on faulty information (see admission by Nature article's co-author - below).
Even if you are willing to give the authors a break for misunderstanding that not all birds are raptors, they failed to even mention the fact that bats are being killed at an alarming rate by wind turbines in the US. The NRC report estimated that by 2020 the annual mortality of bats due to wind turbines may exceed 100,000 just for the Mid-Atlantic region of the eastern US (p. 88). The NRC report concluded that there is a "significant possibility" that wind energy development would adversely impact bat populations in eastern US (p. 5).
The failure to report the significant threat to bats in their article is an astounding oversight given these winged mammals are as much a part of Nature as birds; however, the threat which wind turbines pose to bats runs counter to the "spin" which the authors' attempted to give this story. Furthermore, they also failed to point out the significant habitat impact which industrial wind energy development could wreak, especially when constructed amidst forested ridgetops - which is causing fragmentation of large blocks of forest in the Appalachians. These omissions appear to indicate that the authors distorted or ignored the NRC report's findings so that the article would conform with their bias and popular misconceptions.
Incredibly, one of the most salient points which could be discerned from the NRC report is that the projected growth of the wind industry in the US - 72,000 MW of wind turbines installed by 2020 - would have little impact upon air pollution emissions of NOx, SO2 and even CO2. The NRC report concluded about wind energy's "benefit" regarding NOx and SO2 - the air pollution emissions from fossil-fueled powerplants which result in ozone and acid rain - that there is " only limited opportunity to achieve additional emissions reductions with wind-energy development." (p. 43) and for the Mid-Atlantic Region there "probably will not [be] a significant reduction of these pollutants." (p. 4) As for CO2, the NRC report concluded that wind turbines will offset at most 4.5% of the emissions from powerplants by 2020. However, wind energy development will not cause an actual reduction of CO2 emissions since growth in demand for electricity is expected to cause at least a 10% increase in the tonnage of CO2 emitted from powerplants by 2020 (p. 45) despite having 72,000 MW of wind turbines installed in the US. In addition, electricity generation contributes less than 40% of the total CO2 annually emitted from all sources in the US (p. 42).
It appears "Nature" won't benefit much from this level of industrial wind energy development, but the threat it poses to wildlife and habitat may be significant and harmful.
PS - the NRC's report is accessible via: http://www.vawind.org/Assets/NRC/NRC_Wind.htm
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