The Earth doesn't actually "reflect" most of the Sun's radiation back into space. It's more accurate to say the Earth absorbs some of the radiation and emits it back into space as infrared radiation.

Here's a breakdown:

* Incoming Solar Radiation: The Sun emits a vast amount of energy in the form of electromagnetic radiation, with a significant portion reaching the Earth. This radiation includes visible light, ultraviolet radiation, and infrared radiation.

* Absorption: Some of this solar radiation is absorbed by the Earth's surface, atmosphere, and clouds. This absorption warms the Earth.

* Reflection: A portion of the solar radiation is reflected back into space by clouds, ice, snow, and other reflective surfaces. This is called albedo. The Earth's average albedo is around 30%, meaning about 30% of incoming solar radiation is reflected back into space.

* Emission: The Earth, warmed by the absorbed solar radiation, emits its own radiation. This is primarily infrared radiation, which is invisible to the human eye.

Here's why it's not just reflection:

* Greenhouse Effect: Some of the infrared radiation emitted by the Earth is trapped by greenhouse gases (like carbon dioxide, methane, and water vapor) in the atmosphere. This process, known as the greenhouse effect, is crucial for maintaining a habitable temperature on Earth. However, increased greenhouse gas concentrations can lead to an enhanced greenhouse effect and global warming.

* Different Wavelengths: While some solar radiation is reflected, the majority of the energy that Earth sends back into space is emitted as infrared radiation, which is at a different wavelength than the incoming solar radiation.

In conclusion, the Earth's interaction with solar radiation is complex, involving absorption, reflection, and emission of energy at different wavelengths. The balance between these processes determines Earth's temperature and climate.