I saw a report that said massive use of windmills does indeed have climate altering effects because the air is heated as energy is extracted. On a small scale there will be micro climate effects in the vicinity of a large windmill farm and on a macro scale there will be significant atmospheric heating. There is no free lunch. Sounds like hogwash to me. What about the energy transferred by bending trees as winds flow through forests? Or the energy used to form whitecaps on oceans?