The ionosphere (a layer of the atmosphere) and the surface of the earth form the equivalent of a resonating cavity, similar to the body of an acoustic guitar or violin, except instead of sound what resonates is electromagnetic radiation.
Because EM waves are so fast and the resonating cavity so enormous the resonant wavelengths are very, very, very, very long, on the order of thousands of kilometers and, going back to the guitar analogy, what "plucks the string" so to speak is things like lightning strikes.
Because the waves have such ridiculously long wavelengths, and they are incredibly weak, they don't interact meaningfully with any forms of life.
The ionosphere (a layer of the atmosphere) and the surface of the earth form the equivalent of a resonating cavity, similar to the body of an acoustic guitar or violin, except instead of sound what resonates is electromagnetic radiation.
Because EM waves are so fast and the resonating cavity so enormous the resonant wavelengths are very, very, very, very long, on the order of thousands of kilometers and, going back to the guitar analogy, what "plucks the string" so to speak is things like lightning strikes.
Because the waves have such ridiculously long wavelengths, and they are incredibly weak, they don't interact meaningfully with any forms of life.