How much soil does the earth have that can be used for food growing?
3/4 of the earth is covered by water
1/8 of the earth is covered by swamp, desert, mountains or ice
1/32 of the earth is too rocky
1/32 of the earth is too hot
1/32 of the earth is too wet
1/32 is all that is left and it is only the top layer (peel) that represents the amount of top soil available to grow food crops for the whole world.