Wind speed rises with altitude, and available power rises at the cube of wind speed. (discovermagazine.com)
He knew wind power is related to the cube of wind speed, so faster winds create exponentially more power than slower ones. (discovermagazine.com)
For example tropical storms (hurricanes) don't form unless the sea surface temperature reaches a threshold temperature (~ 26.5 oC according to William Gray) and the while the hurricane wind speed increases around 5 % for each 1 oC of temperature rise, the destructive power in monetory terms increases with something like the cube of the wind speed (e.g. Emanual Nature 436, 686 (2005)-RRB-. (realclimate.org)