Approximately 51% of solar radiation is absorbed by the Earth's surface.

Here's a breakdown:

* 30% is reflected back to space by clouds, the atmosphere, and the Earth's surface (this is called albedo).

* 20% is absorbed by the atmosphere (mainly by clouds and ozone).

* 51% is absorbed by the Earth's surface.

It's important to note that these percentages can vary slightly depending on factors like cloud cover, latitude, and the time of year.