Your gadgets are actually carbon sinks — for now

Dec. 20, 2024

New research finds billions of tons of carbon get trapped in the "technosphere."

At any given moment, crude oil is being pumped up from the depths of the planet. Some of that sludge gets sent to a refinery and processed into plastic, then it becomes the phone in your hand, the shades on your window, the ornaments hanging from your Christmas tree.

Although scientists know how much carbon dioxide is emitted to make these products (a new iPhone is akin to driving more than 200 miles), there’s little research into how much gets stashed away in them. A study published on Friday in the journal Cell Reports Sustainability estimates that billions of tons of carbon from fossil fuels — coal, oil, and gas — was stored in gadgets, building materials, and other long-lasting human-made items over a recent 25 year period, tucked away in what the researchers call the “technosphere.” 

According to the study by researchers at the University of Groningen in the Netherlands, 400 million tons of carbon gets added to the technosphere’s stockpile every year, growing at a slightly faster rate than fossil fuel emissions. But in many cases, the technosphere doesn’t keep that carbon permanently; if objects get thrown away and incinerated, they wind up warming the atmosphere, too. In 2011, 9 percent of all extracted fossil carbon was sunk into items and infrastructure in the technosphere, an amount that would almost equal that year’s emissions from the European Union if it were burned. 

“It’s like a ticking time bomb,” said Klaus Hubacek, an ecological economist at the University of Groningen and senior author of the paper. “We draw lots of fossil resources out of the ground and put them in the technosphere and then leave them sitting around. But what happens after an object’s lifetime?”

The word “technosphere” got its start in 1960, when a science writer named Wil Lepkowski wrote that “modern man has become a goalless, lonely prisoner of his technosphere,” in an article for the journal Science. Since then, the term, a play on “biosphere,” has been used by ecologists and geologists to grapple with the amount of stuff humankind has smothered the planet in.

“The problem is that we have been incredibly wasteful as we’ve been making and building things,” said Jan Zalasiewicz, a professor of paleobiology at the University of Leicester in the United Kingdom, who was not involved in the University of Groningen study.

In 2016, Zalasiewicz and his colleagues published a paper that estimated the technosphere had grown to approximately 30 trillion tonnes, an amount 100,000 times greater than the mass of all humans piled on top of each other. The paper also found that the number of “technofossils” — unique kinds of manmade objects — outnumbered the number of unique species of life on the planet. In 2020, a separate group of researchers found that the technosphere doubles in volume roughly every 20 years and now likely outweighs all living things. 

“The question is, how does the technosphere impinge upon the biosphere?” Zalasiewicz said. Plastic bags and fishing nets, for example, can choke the animals that encounter them. And unlike natural ecosystems, like forests and oceans that can absorb carbon dioxide out of the atmosphere, humans are “not very good at recycling,” Zalasiewicz said.

Managing the disposal of all this stuff in a more climate-friendly way is precisely the problem that the researchers from University of Groningen want to draw attention to. Their research looked at the 8.4 billion tons of fossil carbon in human-made objects that were in use for at least a year between 1995 and 2019. Nearly 30 percent of this carbon was trapped in rubber and plastic, much of it in household appliances, and another quarter was stashed in bitumen, a byproduct of crude oil used in construction.

“Once you discard these things, the question is, how do you treat that carbon?” said Kaan Hidiroglu, one of the study’s authors and an energy and environmental studies PhD student at the University of Groningen. “If you put it into incinerators and burn it, you immediately release more carbon emissions into the atmosphere, which is something we really do not want to do.”

Each year, the paper estimates, roughly a third of these fossil-products in the technosphere get incinerated. Another third end up in landfills, which can act as a kind of long-term carbon sink. But unfortunately, the authors acknowledge, these sites often leach chemicals, burp out methane, or shed microplastics into the environment. A little less than a third is recycled — a solution that comes with its own problems — and a small amount is littered.

“There’s so many different aspects to the problem and treating it properly,” Hubacek said. Nevertheless, he said, landfills are a good starting point if managed well. According to the study, the bulk of fossil carbon that’s put into landfills decays slowly and stays put over 50 years. Designing products in a way that allows them to be recycled and last a long time can help keep the carbon trapped for longer.

Ultimately, Hubacek said, the real solution starts with people questioning if they really need so much stuff. “Reduce consumption and avoid making it in the first place. But once you have it, that’s when we need to think about what to do next.”