Wind farms and surface temperature:instruments misconstrued
In the spring of 2012, media outlets created a story about climate change from a study of wind farms' effect on surface temperature.
Climate change is the study of how the energy balance of the earth can change due to changes in incoming and outgoing radiation between Earth and space. Wind turbines are studied in that context because they purportedly replace the use of fossil fuels to generate electricity or to pump water.
April 29, 2012, Dr. Liming Zhou from SUNY Albany and colleagues published a letter in Nature Climate Change, "Impacts of wind farms on land surface temperature." The study cited a 2010 study showing that wind farms increased surface temperatures, and Zhou et al. found that satellite data showed a slight but significant increase in local temperatures from satellite data overlooking Texas wind farms.
In a flurry of articles in the next two days, media outlets interpreted the effect as local warming, noting that the effect was small. What all reports failed to do was to account for the energy in the whole system, and this might be because Zhou's article assumed readers would know the difference between the energy contained in the ground, and energy contained in the ground and atmosphere together. The use of satellite data, which measures temperature by proxy, measuring radiation to space, has introduced a bittersweet irony in this entire affair—Wind farms are now accused of warming the earth, when in fact the satellite is proving that wind farms are increasing radiation of energy away into space.
References
Liming Zhou, Yuhong Tian, Somnath Baidya Roy, Chris Thorncroft, Lance F. Bosart & Yuanlong Hu. Impacts of wind farms on land surface temperature. Nature Climate Change, letters, advanced online publication, April 29, 2012. http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate1505.html
Baidya, R. S. & Traiteur, J. J. Impacts of wind farms on surface air temperatures. Proc. Natl Acad. Sci. USA 107, 17899–17904 (2010).
