Humans have built a ton of things to keep us alive on this twirling little rock: farms, airports, roads, CDs, houses, computers, landfills, and so forth. All these things are known as the technosphere, and for the first time ever—in a study published last month in the Anthropocene Review—scientists have estimated their total weight: an impressive 30 trillion tons. According to Forbes, that's "enough to add another good-sized mountain to the Appalachians, or perhaps even to the Rockies." Or as a press release breaks it down, it's roughly 110 pounds per square meter of the Earth's surface. Researchers say the technosphere is a "major new phenomenon on this planet" that is "evolving extraordinarily rapidly." It's also a handy means of measuring how much humans have shaped the planet.
Scientists argue that the sheer scale of the technosphere is convincing evidence that we're living in a new, as-yet-unofficial geologic epoch known as the "Anthropocene," Gizmodo reports. The quickest way to be recognized as an epoch is to have a discernible fossil record, and due to the fact that the technosphere is—unlike the biosphere—"remarkably poor at recycling its own materials," that shouldn't be a problem. If "technofossils" from the Anthropocene were classified like normal fossils, there would more than a billion different types, outnumbering the types of species currently alive. (Scientists say Earth entered a new age around 1950.)