From farms and factories to restaurants and homes, about a third of all the food produced in the world goes to waste.

And it’s not just a waste of money and resources. It’s also a major contributor to global warming.

When food rots in a landfill, it produces methane, a potent greenhouse gas.

And when food gets thrown out, more food needs to be grown, processed, packaged, transported, and sold. All of those activities create carbon pollution that warms the climate.

“If food waste was a country, it would be the third-biggest emitter of greenhouse gas emissions on the planet behind the U.S. and China,” says Richard Swannell of WRAP, a U.K.-based NGO that focuses on waste reduction.

His group co-authored a recent report with the U.N. Environment Programme. It found that individual households produce more than 500 million metric tons of food waste a year. That’s more than the amount of food that’s wasted at restaurants and grocery stores combined.

So he says food waste is a problem across the supply chain, but everyone can help by addressing it at home. 

“Buy what you need, and eat what you buy,” he says. “And if we do those two things that will dramatically reduce food waste.”

Reporting credit: Sarah Kennedy/ChavoBart Digital Media