Everyone knows that humanity has an enormous footprint on the planet – but few of us have thought to ask just how much our collective impact weighs. A new study published in The Anthropocene Review examines exactly that question, and has found that the so-called human “technosphere” is bogging down the planet with a staggering 30 trillion tons of infrastructure, development, and manufactured products.
To understand the sheer volume of our impact on the planet, it’s important to recognize what’s being included in the tally. The paper includes all of the structures people have built or modified, as well as all of the gadgets and junk we’ve created – that means everything from farmed land to smartphones is being counted in that estimate. It includes all of our buildings, factories, roads, and trash, “active urban, agricultural and marine components used to sustain energy and material flow for current human life, and a growing residue layer.”
The mass of all the technosphere was estimated using an interesting method – basically, the authors compiled information on the area, thickness, and density of our cities, roads, croplands, and other structures worldwide. This is just one more piece of evidence that the Earth has entered a new geological era, what some are calling the “Anthropocene” epoch.
In order to declare the current era its own geologic epoch, scientists need to be convinced that our footprint will last throughout the planet’s history, -even if our species fades away – as part of the fossil record. It’s hard to argue against the theory – after all, many of our structures will never decompose and may be preserved into the far future. But where previous epochs have been marked by the evolution of new life, our era will be marked in history by “techno-fossils” – the structures and trash we leave behind.