That's bullshit. They can plausibly cause some surprising changes by disturbing the local air circulation patterns (which can either increase or decrease temper

That's bullshit. They can plausibly cause some surprising changes by disturbing the local air circulation patterns (which can either increase or decrease temperatures at a very local level), but increasing the temperature because of friction is a fantasy. If this were happening at a significant scale, it would decrease atmospheric temperatures, because the energy that ends up heating the blades would have to come from somewhere, and the air would lose some of its kinetic energy.