From the unintended consequences department: A new study, which confirms several previous studies, presents observational evidence that shows “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.”
The paper and abstract:
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 Change. doi:10.1038/nclimate1505
The abstract reads
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.
This phenomenon has implications for the surface temperature record in that it tends to bias the readings. Dr. Roger Pielke (University of Colorado) notes that “Because of the redistribution phenomena and the shallow layer affected, observed minimum temperatures are a very poor measure of the accumulation of heat in the atmosphere.” As a consequence, he recommends, “the minimum land surface air temperature should not be used as part of the construction of a global average multi-decadal surface temperature trend.” Pielke maintains that any large-scale land use change such as urbanization and deforestation can have similar results.
I’ve reported a previous study by M.I.T. study that found similar results: