After taking science classes that pitched recycling as a way to keep our forests from disappearing, I always recycled as though a tree’s life depended on it. If anything seems vaguely paper- or plastic-related, I’d toss it into the blue bin with the internal battle cry, I’m a good person and I am saving the trees!

Last month, an unintentionally humbling New York Times report delivered the first blow to my recycling vision. The Times revealed that recycling coffee cups — a personal pastime — is wrong. Same with pizza boxes. And yogurt cups. And plastic containers etched with food residue.

Even more shattering is an investigation from The Baltimore Sun, released today, which found that Baltimore is losing money on recycling, in large part because so many residents are recycling wrong. In just seven years, profits from recycled goods have dropped three-quarters, while the cost of filtering out wrongly recycled items has increased. Paper in Baltimore, for instance, once brought in $112 a ton, but now its value is barely $30 a ton. That’s in line with the national trend. A USA Today story from last year claimed that recycling profits, especially from glass, are down across the U.S., and people who recycle items that seem recyclable but actually aren’t — known as “aspirational recyclers” — are a major culprit.

Cost-effectiveness is not usually one of recycling’s strengths, not least because the cost of the alternatives — manufacturing new materials or maintaining dumps where the old materials may leach into soil — is abstract and difficult to quantify. But it turns out, people externalizing their anxiety about saving the planet with wishful thinking about what is actually recyclable will only make the problem worse.

In fact, the expert consensus is that, if you aren’t completely sure whether something can be recycled, don’t recycle it. As Michael Taylor, a recycling operations executive at Waste Management, told the Sun: “Our message is, when in doubt, throw it out.”