About 30% of the Sun's energy that reaches Earth is reflected back to space, mostly due to bright surfaces like clouds and snow.
On average, about 30% of the Sun's energy intercepted by Earth is reflected back to space. This phenomenon is primarily due to the reflection by clouds, snow, and other bright surfaces. Earth's overall albedo, or reflectivity, indicates that 70% of the incoming sunlight is absorbed, subsequently warming the planet's land, water, and atmosphere. The presence of light-colored surfaces and entities like snow and clouds contribute to this reflection percentage, while darker surfaces tend to absorb more sunlight.
So, the portion of the sunlight that is not absorbed assists in keeping the Earth's energy budget balanced by reflecting a significant proportion of solar energy back into space.