They used satellite data to show that land around newly constructed wind farms warmed more than next-door areas.
The result – published in the journal Nature Climate Change – confirms an earlier, smaller study from 2010.
The scientists believe the effect is caused by turbines bringing relatively warm air down to ground level.
They suggest that turbines in other places might not produce the same value of ground temperature change.
The study area, in west-central Texas, saw a major turbine building programme in the middle of the last decade, with the number soaring from 111 in 2003 to 2325 just six years later.
Researchers used data from the Modis instruments on Nasa’s Aqua and Terra satellites to measure ground temperatures across the study region and between the beginning and end of the construction boom, defined as the difference between the average for 2003-5 and that for 2009-11.
The entire region saw a rise, but it was more pronounced around wind farms.”
“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.”