NOTE: An update has been added below, using the press release that came out today after the news stories yesterday.
While ironic that something designed to reduce CO2 emissions (and presumably warming)is actually producing warming around it, this isn’t really any big surprise. Orchardists and vineyard operators in California have been using motor driven wind turbines to elevate local temperatures to save crops from frost for over half a century. What is different here is the scale of nighttime warming, large enough to be visible on MODIS satellite imagery thanks to large scale wind farms.
Dr. Roger Pielke Sr. and associates have been doing research along these lines for quite some time, and has this summary on some recent research.
From Louise Gray in the Telegraph:
Wind farms can cause climate change, according to new research, that shows for the first time the new technology is already pushing up temperatures.
Usually at night the air closer to the ground becomes colder when the sun goes down and the earth cools. But on huge wind farms the motion of the turbines mixes the air higher in the atmosphere that is warmer, pushing up the overall temperature.
Satellite data over a large area in Texas, that is now covered by four of the world’s largest wind farms, found that over a decade the local temperature went up by almost 1C as more turbines are built. This could have long term effects on wildlife living in the immediate areas of larger wind farms. It could also affect regional weather patterns as warmer areas affect the formation of cloud and even wind speeds.
Full story here:
Here’s the paper:
Zhou, Liming, Yuhong Tian, Somnath Baidya Roy, Chris Thorncroft, Lance F. Bosart and Yuanlong Hu 2012: Impacts of wind farms on land surface temperature. Nature Climate Chnage. doi:10.1038/nclimate1505
And the abstract (bold mine):
The wind industry in the United States has experienced a remarkably rapid expansion of capacity in recent years and this fast growth is expected to continue in the future. While converting wind’s kinetic energy into electricity, wind turbines modify surface–atmosphere exchanges and the transfer of energy, momentum, mass and moisture within the atmosphere. These changes, if spatially large enough, may have noticeable impacts on local to regional weather and climate.
Here we present observational evidence for such impacts based on analyses of satellite data for the period of 2003–2011 over a region in west-central Texas, where four of the world’s largest wind farms are located. Our results show a significant warming trend of up to 0.72 °C per decade, particularly at night-time, over wind farms relative to nearby non-wind-farm regions. We attribute this warming primarily to wind farms as its spatial pattern and magnitude couples very well with the geographic distribution of wind turbines.
h/t to WUWT reader Andrew Kissling
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UPDATE: 4/30/12:30PM PST The press release came out this morning, including this image:
Temperature Differences near Wind Farms
This graph shows the night-time land surface temperature differences near wind farms between 2010 and 2013. Credit: Liming Zhou et al., Nature Climate Change
Here’s the PR:
Scientists find night-warming effect over large wind farms in Texas
Wind turbines interact with atmospheric boundary layer near the surface
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  IMAGE:Wind farms are numerous in parts of Texas; scientists report new results on their effects.Click here for more information. |
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Large wind farms in certain areas in the United States appear to affect local land surface temperatures, according to a paper published today in the journal Nature Climate Change.
The study, led by Liming Zhou, an atmospheric scientist at the State University of New York- (SUNY) Albany, provides insights about the possible effects of wind farms.
The results could be important for developing efficient adaptation and management strategies to ensure long-term sustainability of wind power.
“This study indicates that land surface temperatures have warmed in the vicinity of large wind farms in west-central Texas, especially at night,” says Anjuli Bamzai, program director in the National Science Foundation’s (NSF) Division of Atmospheric and Geospace Sciences, which funded the research.
“The observations and analyses are for a relatively short period, but raise important issues that deserve attention as we move toward an era of rapid growth in wind farms in our quest for alternate energy sources.”
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 IMAGE:This graph shows the night-time land surface temperature differences near wind farms between 2010 and 2013.Click here for more information. |
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Considerable research has linked the carbon dioxide produced by burning fossil fuels with rising global temperatures.
Consequently, many nations are moving toward cleaner sources of renewable energy such as wind turbines. Generating wind power creates no emissions, uses no water and is likely “green.”
“We need to better understand the system with observations, and better describe and model the complex processes involved, to predict how wind farms may affect future weather and climate,” said Zhou.
There have been a growing number of studies of wind farm effects on weather and climate, primarily using numerical models due to the lack of observations over wind farms.
As numerical models are computationally intensive and have uncertainties in simulating regional and local weather and climate, said Zhou, remote sensing is likely the most efficient and effective way to study wind farm effects over larger spatial and longer temporal scales.
To understand the potential impact of wind farms on local weather and climate, Zhou’s team analyzed satellite-derived land surface temperatures from regions around large wind farms in Texas for the period 2003-2011.
The researchers found a night-time warming effect over wind farms of up to 0.72 degrees Celsius per decade over the nine-year-period in which data were collected.
Because the spatial pattern of warming mirrors the geographic distribution of wind turbines, the scientists attribute the warming primarily to wind farms.
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.
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 IMAGE:Wind farms dot the horizon in Lubbock County and other Texas areas.Click here for more information. |
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“This warming effect is most likely caused by the turbulence in turbine wakes acting like fans to pull down warmer near-surface air from higher altitudes at night,” said Somnath Baidya Roy of the University of Illinois at Urbana-Champaign, a co-author of the paper.
While the warming effect reported is local and small compared to the strong background year-to-year land surface temperature variation, the authors believe that this work draws attention to an important scientific issue that requires further investigation.
“The estimated warming trends only apply to the study region and to the study period, and thus should not be interpolated into other regions, globally or over longer periods,” Zhou said. “For a given wind farm, once there are no new wind turbines added, the warming effect may reach a stable level.”
The study represents a first step in exploring the potential of using satellite data to quantify the possible effects of the development of big wind farms on weather and climate, said Chris Thorncroft of SUNY-Albany, a co-author of the paper.
“We’re expanding this approach to other wind farms,” said Thorncroft, “and building models to understand the physical processes and mechanisms driving the interactions of wind turbines and the atmosphere boundary layer near the surface.”
Other authors of the paper include Lance Bosart at SUNY-Albany, Yuhong Tian of NOAA, and Yuanlong Hu at Terra-Gen Power LLC in San Diego, Calif.
lookitup,
It is what the ground observer can see looking straight up into the sky. NOT what the sky can “see” of the ground, as you mistakenly stated. Thus, the existence of buildings do not make a bit of difference; you’re looking straight up, see?
Look it up. It’s easy.
First of all, how hard is it to get my tag right? Second of all, it’s emphatically not about looking straight up. The ground emits heat in all directions, including angled (i.e., not directly) upwards. It’s this “angled” heat that’s being blocked by buildings. The cutting off of the horizon is what’s under discussion here. Building large buildings cuts off the average amount of sky visible from the ground; this increases the length of the average radiative path from the ground to the top of the atmosphere.
The Christian Science Monitor:
Don’t believe the headlines. Wind farms do not cause ‘global’ warming.
http://www.csmonitor.com/Science/2012/0430/Don-t-believe-the-headlines.-Wind-farms-do-not-cause-global-warming
lookitupitseasy says:
Actually, it is about looking straight up. Maybe you missed the previous discussions here concerning using an IR camera to measure downwelling IR by looking straight up. That is the only way to get an accurate reading, otherwise by looking at the horizon, you are looking through many more miles of atmosphere, which skews the readings. I suggest spending some time reading the WUWT archives, before commenting on this particular point. Otherwise you’ll come across as clueless as billy connolley.
It’s not clear at all to me why you think an old discussion about a different phenomenon is relevant here. Indeed, downwelling IR coming straight down doesn’t care whether it hits a flat roof or the flat ground. But this is unrelated to the question of how IR being radiated from the ground behaves, what direction it goes in, and what blocks it. I’m kind of shocked that you haven’t even reached the point of understanding what the question is yet, but perhaps I shouldn’t be — after all, you can’t even seem to master the art of typing in my handle correctly ;).
By the way, your throwaway about WMC is really silly: if you were actually reading my posts, you would have figured out that I don’t have any idea whether his claims are correct, because to know that would require a person to do a lot of fairly serious math that I certainly haven’t done. All I’ve pointed out is that davidmhoffer decided to take a swing at WMC without even understanding WMC’s argument; similarly, you have now picked up davidmhoffer’s banner without understanding even a little bit the position you’re trying to disprove. It seems to me that, this being a science blog and all, you should time would be better spent explaining to someone like edbarbar how completely, tragically, embarrassingly wrong he is than arguing with me.
lookitup,
I won’t argue with someone who knows it all.
BTW, you are humor impaired. edbarbar’s comment was meant to be funny. Not that you noticed.
Gosh, I hope you’re right about edbarbar — that would restore some of my faith in humanity. Two silly questions: 1) what do you think the “tell” is that I should have picked up on? 2) Who do you think his joke is mocking?
Everybody seem to missing the elephant in the room, wind farms do cause global warming but not buy the mixing method.
Essentially wind farms work by taking power from the air flows which cool the earth, these are the air flows which allow warm air to rise and cool and cooler air to fall to the ground.
When you slow that process you get warming.
We humans actually use a similar process to stay warm, but we raise hairs on our body to trap air not wind mills. It’s pretty basic stuff but has been over looked.
I argue the case against strong opposition here and I think I win!!
http://www.scienceforums.net/topic/66151-do-wind-turbines-slow-down-the-wind/
lookupitseasy,
Apologies for being lazy in typing your screen name. Also, I don’t get the “tell” comment and I’m still too lazy to search for it. But regarding edbarbar’s comment:
“I’m certain in five years from now, Al Gore’s son will tell us the consequences of relying on Wind power, that Solar has destroyed our deserts, and the only way to get good power is hamsters on a hamster wheel. But only one hamster per household, because the excess C02 output might cause another unacceptable increase in global temperatures.”
That was funny to me. And speaking of Al Gore’s son:
http://www.theonion.com/articles/al-gore-places-infant-son-in-rocket-to-escape-dyin,2495
http://www.scienceforums.net/topic/66114-wind-farms-cause-global-warming/
actually i gave the slightly wrong link above
@Smokey says: May 2, 2012 at 6:47 pm
A “tell” is a poker term professional players use. It is a mannerism, or inflection that indicates when a player is bluffing. The best players are always looking for the “tell” of an opponent to gain an advantage. In the case used here, look it up was sarcastically asking how you could “tell” that edbarbar was joking.
philjourdan,
Thanks for the explanation. When I want to gain an advantage, I ‘tell’ the truth and use verifiable facts. And as always, I wear my heart on my sleeve.
philjourdan, thanks for the translation. I was using “tell” in the sense of “that which gives away”, i.e., I was asking what part of edbarbar’s post indicates that it’s a joke, rather than an argument intended in seriousness. (It seems to me that esboella is making the essentially the same, horribly wrong, argument. But I don’t think esboella is joking, do you?)
Smokey – Do not play poker – it is not a game for the honest! (I suck at it, but do enjoy playing). 😉
Lookupitseasy- your use is correct. That is pretty much how poker players use the term. My tell is bad so I only play penny poker. No one is going to study you intently over a dollar pot.