Why is thermal energy from the Sun transferred to Earth through electromagnetic waves instead of any other type of thermal energy transfer?

Because electromagnetic waves can travel through empty space

Explanation:

The energy that is emitted from the sun is transferred to the earth in the form of radioactive waves. These waves are originated due to the vibration between the electric and magnetic fields. As this energy reaches the earth, it warms the earth's atmosphere, resulting in the transfer of heat energy in three possible ways namely the conduction, convection, and radiation.

This electromagnetic waves do not require any matter for the transmission of energy, and can easily travel in empty space from the core of the sun to the earth and other nearby planets. Whereas other types of waves cannot travel in space, so it is transferred in the form of electromagnetic waves only.

The electromagnetic waves can pass through empty space.