>Woooow, so we have multiplied the mammal population on earth by ten respect the "natural" population.

We've also eliminated a lot of habitat so we can live there, and hunted several species into, or near, extinction on land and in the sea. So, all of that is biomass that would "naturally" exist without our interference. So, no, we haven't multiplied the biomass by 10x what it would "naturally" be.