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.
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.
Infrastructure will continue to expand, fastest in developing cities, says Xuemei Bai, who studies urban sustainability at the Australian National University. All the energy involved in producing raw materials could jeopardize international climate goals, she notes. But cities offer an efficiency of scale not possible in rural locations, because they have fewer roads and water mains per person, for example. And technological and policy innovation could help reduce the environmental impact of humanity’s massive footprint, Bai says. "I’m hopeful. It is possible."