"As China plans new era of turbine power, the technology may not be as green as it seems" from South China Morning Post

"Theoretically, though, the possibility is there. In 1961, American mathematician and meteorologist Edward Lorenz discovered by computer modelling that in a chaotic and sophisticated system such as atmosphere, a disturbance as small as the flap of a butterfly's wings could set off a tornado thousands of kilometres away. It has come to be known as the Butterfly Effect."


"For decades, wind industry designers have been mining the catalogue of airfoil profiles developed by the US National Advisory Committee for Aeronautics, the predecessor of Nasa, to determine the shape of the most efficient blades. The chosen blades were tested in a wind tunnel to ensure the maximum lift and minimum drag in a given environment, such as Inner Mongolia."


"Hu Yongyun, professor of the School of Physics' Department of Atmospheric and Oceanic Sciences at Peking University, said wind turbines were unlikely to dramatically alter regional climate, such as precipitation, as long as they stayed small.

"In my opinion, wind farms of less than a dozen square kilometres should have little impact on climate because a thunderstorm, for instance, requires a much larger area to form," Hu said."

But large-scale wind farms were another matter, he said. China is building seven such major bases. One in Jiuquan, Gansu, covers nearly 200,000 square kilometres."


"The Butterfly Effect certainly exists, but rarely do scientists consider it in practice. Even something as large as a wind turbine is often neglected because we consider only the air movement high up in the atmosphere, more than a dozen kilometres above sea level," he said."