The combined weight of human-made objects will likely exceed that of all living things on Earth by the end of this year, weighing a total 1.1 trillion metric tons, or teratons, according to a new study published in the journal Nature. The study also found that the amount of new objects being manufactured every week weighs as much as all 7.7 billion people on the planet.
“The significance is symbolic in the sense that it tells us something about the major role that humanity now plays in shaping the world and the state of the Earth around us,” Ron Milo, an environmental scientist at the Weizmann Institute of Science in Israel and co-author of the study, told BBC News. “It is a reason for all of us to ponder our role, how much consumption we do and how can we try to get a better balance between the living world and humanity.”
Milo and his team had previously produced an estimate on the total weight of biomass on Earth, and they wanted to compare that number to the total mass of human-made objects. To figure that out, they examined data sets on the flow of materials around the world, Scientific American reported.
The researchers estimate that at the beginning of the 20th century, human-made items equaled just 3 percent of total biomass, including all plants and animals. But total “anthropogenic mass,” as the scientists call it, on Earth has doubled every 20 years for the past 100 years. Today, humans produce more than 30 billion metric tons of new material every year, from plastics to building materials to clothing to cell phones. And if current production growth rates continue, the total weight of human-made objects could hit 2.2 trillion tons by 2040 — twice as much as all living biomass.
Those numbers, the scientists say, include only those objects in use today, not waste. If waste were added, anthropogenic mass surpassed biomass in approximately 2013.