According to an article in Nature today, a new study by the Weizmann Institute of Science in Israel looked at the composition of human-made objects. It found that concrete, aggregates, bricks, asphalt, metals and other materials as the main building materials nearly exceeded the biomass of nature itself. If waste was factored in, the study found, we will have easily passed nature in what is called "anthropogenic mass."
We find that Earth is exactly at the crossover point; in the year 2020 (± 6), the anthropogenic mass, which has recently doubled roughly every 20 years, will surpass all global living biomass. On average, for each person on the globe, anthropogenic mass equal to more than his or her bodyweight is produced every week. This quantification of the human enterprise gives a mass-based quantitative and symbolic characterization of the human-induced epoch of the Anthropocene.
Because all human stuff could not actually be weighed, present and historical masses of all on Earth dated back to 1900 were estimated using computer models. The results showed over the last 120 years the amount of biomass has decreased, but this is not as good as the exponential growth in goods produced by humans. Data show that the best estimate for the amount of life on planet Earth is around 1,1 teratonnes.