One of the theories of global warming is that the polar regions will warm faster than the tropics. If that is true (I think it is questionable), the "temperature gradient" will weaken which means, in general, less wind. We learned about the temperature gradient and its relation to wind in Meteorology 101 (really).
Apparently, Big Wind and its goal to fight global warming never considered this conundrum. So, even though there are more wind wind turbines than last year, wind energy production is down 6% when compared to the same time last year. Sheesh. [link fixed, sorry]