I’ve been getting increasingly excited about the potential of wind power recently. But a new paper suggests that wind turbines, installed broadly, might actually change the climate themselves just by disrupting the normal flow of the wind:
In a paper published online Feb. 22 in Atmospheric Chemistry and Physics, [the MIT researchers] Wang and Prinn suggest that using wind turbines to meet 10 percent of global energy demand in 2100 could cause temperatures to rise by one degree Celsius in the regions on land where the wind farms are installed, including a smaller increase in areas beyond those regions. Their analysis indicates the opposite result for wind turbines installed in water: a drop in temperatures by one degree Celsius over those regions….In the analysis, the wind turbines on land reduced wind speed, particularly on the downwind side of the wind farms, which reduced the strength of the turbulent motion and horizontal heat transport processes that move heat away from the Earth’s surface. This resulted in less heat being transported to the upper parts of the atmosphere, as well as to other regions farther away from the wind farms. The effect is similar to being at the beach on a windy summer day: If the wind weakened or disappeared, it would get warmer.
I have wondered about this effect before but always assumed it would be negligible. Apparently it isn’t. For now, the researchers don’t say this is necessarily an argument against developing wind power, though-they just want us to investigate the effect more before investing huge sums in wind farms.We’re a long way from this being an immediate problem. And analyses like this are extremely unreliable because there are so many unaccounted-for factors. Who knows how the earth’s surface and climate patterns will change in the next few years? It could also be that the carbon emissions saved by a large-scale shift to wind power more than make up for the warming effects of turbines.But it would still be nice to figure out a solution to this (potential) problem. I wonder if the kite-style turbines that can fly at high altitudes would also have this effect.Photo (cc) from Flickr user the russians are here.
