It takes ONE million years to form One cm of top soil. Do you know how much we loose during rain every year?

1cm per 1Ma is a bit excessive. I think you need to revise your estimate. Dust accumulation on a bookshelf would be higher than that.

Depends where you are. Areas in the tropics that have been deforested can lose feet of soil in a few days, Arid climates like the Western US can loss up to an inch and while the Eastern US usually losses very little if there is vegetation present. The thing you have to remember is soil just doesn't go away. It gets deposited somewhere else, and in desert climates wind generally brings soil to replaces that which was washed away.

I am a little worried about your sources. When you say it takes 1 million years to create a cm of top soil, what spacial scale are you looking at. In my back yard, I can create feet of topsoil in just a few years by composting.

I'm suspicious of that statistic. Who made measurements a million years apart? Wouldn't the real number vary by location.

I don't know how much is lost. I know it's substantial.

i am a bit nervous to answer this

many