[ableChair]

OMG!, now you're arguing the ENGLISH! It plainly says that only 5% reaches the surface. Denial ain't just a river in Egypt.

[Dan Evans]

"Only 49 percent of the available solar radiation reaches the surface of our planet [all types - my comment], 5 percent through direct radiation, 22 percent through clouds and 22 percent by downwards scattering in the atmosphere".

5 percent gets through directly but 22 percent is scattered. But the index of scattering of light is proportional to the fourth power of the frequency so blue light is scattered 16 times as much as red light (that's why the sky is blue). So about 20 percent of the red light is not scattered and a total of about 25 percent of the red light gets through directly (when you consider clouds).

About half the time it's cloudy, but if there were no clouds, then the 22 percent that we get through clouds would get through directly and therefore about 50 percent of the red light from the sun would get through directly.