They calculate the weight of all constructions by man

A group of geologists have calculated the weight of all the comstructions made by the humanity and the results are huge.
They have called all that the technosphere, a new part of the earth created by the man that is invading the biosphere, and the results of the weight of that techonsphere are the creepy cipher of 30 billion of tones.
The man have conquested the earth and now we have created a new part of the earth the technosphere. This is interesting because we don't know when we'll pass the limit.