It’s not just your storage unit that’s packed to the gills. According to a new study, the mass of all our stuff — buildings, roads, cars, and everything else we manufacture — now exceeds the weight of all living things on the planet. And the amount of new material added every week equals the total weight of Earth’s nearly 8 billion people. “If you weren’t convinced before that humans are dominating the planet, then you should be convinced now,” says Timon McPhearson, an urban ecologist at the New School who was not involved with the research. “This is an eye-catching comparison,” adds Fridolin Krausmann, a social ecologist at the University of Natural Resources and Life Sciences, Vienna, who also was not involved in the work. There are many measures of humanity’s impact on the planet. Fossil fuels have sent greenhouse gases soaring to levels not seen in at least 800,000 years. Agriculture and dwellings have altered 70% of land. And humans have wiped out untold numbers of species in an emerging great extinction. The transformations are so great that researchers have declared we’re living in a new human-dominated age: the Anthropocene.