Benjamin Sovacool agrees that wind turbines kill birds and bats, but this University of Singapore public policy professor makes a convincing case that this fact desperately needs context. Reviewing avian mortality from power generation in the June issue of Energy Policy, Sovacool shows that — gigawatt-hour for gigawatt-hour — it is fossil-fired power by a longshot that will ground winged creatures.
Sovacool’s analysis estimates avian deaths throughout the fuel cycle for coal, oil and natural-gas fired power generation:
- Coal mining = 0.02 deaths per gigawatt-hour (GWh). For example, habitat destruction by mountaintop removal coal mining in Appalachia has killed approximately 191,722 Cerulean Warblers.
- Plant operations = 0.07 bird deaths/GWh. Electrocution at one well-observed power plant in Spain killed 467 birds over two years.
- Acid rain = 0.05 deaths/GWh. Cornell’s Laboratory of Ornithology estimated in 2002 that acid rain reduced the U.S. wood thrush population by 2–5%.
- Mercury emissions = 0.06 deaths/GWh. Impacts include hampered reproduction and survival, observed in everything from albatross and woodstorks to bald eagles.
Summing these conventional risk factors gives an estimated 0.2 fatalities/GWh from fossil power — small compared to Sovacool’s comprehensive estimate of 0.3-0.4 fatalities/GWh for wind power. But that’s without climate change.
An international collaboration reporting in Nature in 2004 predicted that shifting climate would commit 15–37% of all species of birds to extinction by 2050. And that was based on one of the mid-range scenarios from the International Panel on Climate Change, whose predictions look increasingly conservative. Sovacool considers that study and others and estimates that the roughly two-fifths of greenhouse gas emissions generated by fossil-fired power cause 4.98 avian deaths/GWh — a whomping stomp that leaves wind power in the dust.
Now Sovacool could be off. He calls for further research, noting that estimating the impact of climate change on birds adds further levels of complexity to an already uncertain science. But he’ll have to be way off to change the basic conclusion that shifting from coal-fired power to wind power is a very good trend for birds and bats.
This post was created for Energywise, IEEE Spectrum’s blog on green power, cars and climate