Every year the Royal Statistical Society chooses an International Statistic of the Year. Like all the other end-of-year listicles and roundups you’ve seen, it’s meant to capture some of the zeitgeist in a convenient, clickable package.
In 2017, the panel voted for the number 69: the number of Americans killed by lawnmowers every year (they compared it to two, the number of Americans killed by immigrant terrorists). This year’s take is a bit less whimsical.
It comes from a 2017 study in the journal Science called “Production, use, and fate of all plastics ever made.” It is a wild read. The authors estimate that as of 2015, there had been 6.9 billion tons of plastic waste generated around the world, 79 percent of which ended up in a landfill or in nature and 12 percent of which got incinerated.
The sheer scale of that number is hard to fathom. One statistician writing for The Conversation calculated that, assuming you could fit 31 plastic bottles into a grocery bag (she tested it), the amount of non-recycled plastic waste would fit into roughly 7.2 trillion bags. But even that’s hard to imagine. When’s the last time you visualized a trillion grocery store bags? So we tried breaking it down a little differently in the hopes that we can somehow convey the true enormity of the problem.
Nerd note: these calculations are assuming that the grocery bag is one foot wide by one foot high, which is what the original statistician assumed. We converted plastic to shirts by assuming that 31 bottles fit into those 7.2 trillion bags, and that it takes 8 bottles to make a shirt. That number varies by company, but for instance the recycled shirts made for the 2010 World Cup were made from 8 bottles each. Also we assumed that roughly 45 shirts per year for 80 years was a sufficient lifetime supply, though your mileage may vary.