They do disturb the Earth's ionosphere, however, which in turn disturbs radio communications. Along with energetic ultraviolet radiation, they heat the Earth's outer atmosphere, causing it to expand.

Solar Flares Can Cause Radio Blackouts on Earth\n\n When a strong enough flare occurs, charged electrons in the upper atmosphere can temporarily disrupt radio waves on the side of Earth that is facing the Sun, either degrading or completely absorbing them.