[jacquesm]

Compared to the amount of power in the weather system what we puny humans can do it insignificant. A typical wind turbine causes a slow-down behind it but that's only in the layer that windmill sits in. Given that the atmosphere's active airmass extends many 100's of time above the height of the highest windmills and windmills will only ever cover a very small fraction of the surface area of the planet their effect is negligible.

[Applejinx]

Yes. Anything we can do is a millionth of the size of the flowing climate, its temperatures and airmasses. It becomes a heck of a potential power source, but nothing we do with windmills is going to have the least effect on it.