[Joseph Katz]

Joseph Katz  asked the Naked Scientists:
   
I have been told that "the weight of all the bacteria on earth together it is more than the combined weight of all OTHER life on Earth".  Yet I can not figure out, what that mass is?

My question is how much mass does all the life on earth equal (even as a percentage of the Earths mass would be interesting).

Thank you,

Joseph Katz

What do you think?

[CliffordK]

Here is an estimate that I found online (see link).

"Estimates of the total mass of the biosphere are more than 1 TtC (trillion tons of C) and perhaps as much as 4 TtC.".

I suppose it is odd to estimate the mass of life based on just the mass of carbon.  However, it is probably appropriate at least to estimate using dry weight.