Land cools each night when the sun goes down. Hot air rises. Fans circulate air. Wind speeds pick up at night. This combination of familiar facts mean that wind turbine blades move warmer air back down lower than usual over large wind farms.
A small study measuring that effect, Impacts of wind farms on land surface Temperature a paper in Nature by scientist Liming Zhou and his team at the University of Albany, measured the resulting ground surface temperatures from 2003 to 2011 near large wind farms in West-Central Texas and estimated the result could be three quarters of a degree (Celsius) difference.
The fossil-funded media is reporting with glee that yes, Virginia, golly-gee, these wind farms cause climate change.
Conservative media outlets, including Fox Nation, Rush Limbaugh and Jim Hoft, are distortingthe research to claim that wind farms “cause global warming” and Fox News’ morning show concluded “wind ain’t working.”
But here is what Zhou actually says:
“The wind turbines do not create a net warming of the air and instead only re-distribute the air’s heat near the surface, which is fundamentally different from the large-scale warming effect caused by increasing atmospheric concentrations of greenhouse gases,” says Zhou.
This action of warm air being recirculated downwards by the moving turbine blades is well known to farmers. Citrus growers use big fans to protect crops from frost. Hot air rises. Farmers use large fans to bring it back down to warm near the ground. Similarly, these citrus growers’ fans “do not create a net warming of the air” they recirculate air that is warmer to begin with.
There is some unfortunate language in the paper. Some climate scientists appear to be as innocent of caution about our moronic media over-simplification, and no more expect to have their words twisted by the fossil-funded think tanks than do other scientists studying the mating habits of shrews.
But, per the IEA, there is about $4 trillion worth of dirty energy that we need to buy over the next few decades if we don’t switch to clean energy. There’s nobody who cares about what you think of the mating habits of shrews. But climate science is different. The richest industry on the earth is not taking losing $4 trillion to the competition lying down. Climate scientists are in the cross hairs. They need to be more careful.
Zhou’s abstract at Nature summarises (and the short abstract is all the media can access for free) ”While converting wind’s kinetic energy into electricity, wind turbines modify surface–atmosphere exchanges.”
This could be twisted into the idea that some weird science-y peculiarity to some particular way that wind turbines “convert kinetic energy to electricity” that causes the warming.
Similarly loosely written, the abstract mentions “a significant warming trend of up to 0.72 °C per decade.” This three quarters of a degree rise can (and will) be misconstrued as ongoing rising temperatures over the decades, just like those caused by greenhouse gases, which do accumulate over each decade, so a 1 degree rise “per decade” results in a 10 degree rise in 10 decades. That is quite different.
What would gave been clearer would be to simply say that as more turbines were added, the land surface temperature rose.
And that is how Zhou puts it in the Q&A that was necessitated by the uproar:
“The year-to-year land surface temperature over wind farms shows a persistent upward trend from 2003 to 2011, consistent with the increasing number of operational wind turbines with time” says Zhou in the Q&A. “FAA data shows that the number of wind turbines over the study region has gone up from 111 in 2003 to 2358 in 2011.
No one writing about climate change and its solution: clean energy should risk misinterpretation. I’ve had commenters who believe that wind turbine blades are moved around by diesel generators.
But I am an intermediary, like everyone who writes for clean energy and climate policy blogs. I know what’s out there. I see first-hand how well the opposition (with $4 trillion to lose) has funded the opposing view. But Zhou, like most scientists, obviously assumes that his readers are rational people.
A scientist will read “instead only re-distribute the air’s heat” and understand that it means that it is merely the fan-like action of wind turbines that moves warm air back down to the ground. That warmth was there all along, but higher up. Over wind farms it is moved down. That’s all.
Susan Kraemer writes at CleanTechnica, CSP-Today, PV-Insider , SmartGridUpdate and GreenProphet and has been published at Ecoseed, NRDC OnEarth, MatterNetwork, Celsius, EnergyNow and Scientific American. As a former serial entrepreneur in product design she brings an innovator's perspective on inventing a carbon-constrained civilization: If necessity is the mother of invention: solving climate change is the mother of all necessities! As a lover of history and sci fi, she enjoys chronicling the strange future we are creating in these interesting times. Follow Susan @dotcommodity on twitter.