Human-made materials outweigh living biomass
Journal Nature A PinP photo. The year 2020 may mark the crossover point when human-made mass surpasses that of living biomass according to a study published in Nature this week. The mass embedded in human-made items, such as buildings, roads and machines, has doubled every 20 years for the past 100 years. These findings underscore the increasing impacts that humans have on Earth. Since the first agricultural revolution humans have halved plant biomass, from around 2 teratonnes (2,000,000,000,000 tonnes) to the current value of around 1 teratonne, through land-use changes such as agriculture and deforestation. The increasing production and accumulation of human-made objects (termed anthropogenic mass) has also contributed to a shift in the balance between living and human-made mass. Ron Milo and colleagues estimate changes in global biomass and human-made mass from 1900 to the present day. They show that at the beginning of the twentieth century, the mass of hu