Human-made materials such as plastics, buildings and cars now weigh more than all the biomass on the planet, a new study shows.
According to a new analysis, the amount of "stuff" mankind has created from the planet's resources has reached 1.1 teratons - or roughly 1,100,000,000,000 metric tons.
Israel's Weizmann Institute of Science published its findings in the scientific journal Nature Wednesday. The study aims to gauge the effect humans have had on the planet to date and how much of its resources we have consumed.
To get to the estimated weight, researchers divided human-made items into six categories - concrete, glass, wood, metal, aggregates (such as gravel), bricks and "other materials" such as plastic.
In the study, researchers said that the majority of the mass had come from concrete, asphalt, bricks and aggregate which make up most of our cities and infrastructure. Researchers didn't include waste in calculations. If they did, human-made "stuff" would have outweighed living things on the planet in 2013, the study said.
Researchers categorized the planet's biomass into six categories - plants, fungi, bacteria, protists, single-celled archaea and animals (including humans). Plants make up about 90% of the planet's biomass.
The study said humans made significant changes to the planet in a relatively short time. Since our civilization began, pegged during the invention of agriculture more than 12,000 years ago, humans have cut the planet's biomass by nearly 50% - from 2 teratons to 1.1 teratons.
Researchers estimate humans are generating human-made mass at a rate of roughly 30 gigatons - or 30 billion tons - per year. The rate of production accelerated after World War Two. Before then, human-made items were about 3% only of the planet's biomass.
The University of Natural Resources and Life Sciences in Vienna, which was not involved in the study, said that the new research should send a strong message to people and more attention to how our civilization is affecting the planet.
Authors of the study said that while their research was symbolic, humanity should acknowledge the alarming figures and take stock of its current role on the planet.
