Somewhere in your fridge, a bag of spinach is quietly becoming a climate problem.It has company. The world threw away 1.05 billion tons of food in 2022. That’s more than a billion meals a day. Food loss and waste now drive 8 to 10 percent of global greenhouse gas emissions. That’s nearly five times the aviation industry.

The real damage starts after the garbage truck pulls away.

Buried in a landfill, cut off from oxygen, food rots into methane. Methane traps 80 times more heat than CO2 over 20 years and has driven about 30 percent of warming since the Industrial Revolution. Landfills, dumps, and wastewater produce roughly a fifth of the methane humans emit. In the U.S., landfills are the third-largest source of human-caused methane, and food is the single biggest thing filling them.

Here’s the good news buried in all that rot.

Methane is fast. CO2 lingers for centuries. Meanwhile, most methane is gone within a decade. If we cut methane now, the planet feels it fast. That makes food waste one of the highest-leverage climate fixes we have. ReFED calculates that fully rolling out proven food waste solutions would cut 77 million metric tons of emissions annually. That’s nearly the same as pulling 18 million gas-powered cars off the road.

So the question isn’t whether it matters. It’s where we start.

Start in your kitchen. Shop with a list. Store produce so it lasts. Freeze what you won’t eat this week. Treat “best by” as a suggestion, not a verdict. Compost the rest. Households generate 60 percent of the world’s food waste, so these habits do add up.

But nobody should have to beat the system one leftover at a time. Right now, the system is working against us:

• Date labels are a mess. No federal standard exists, so in most states “sell by,” “best by,” and “use by” mean whatever the manufacturer wants. The confusion sends 3 billion pounds of food to the trash every year.
• Burying food is the cheap default. Most states let food go straight to the landfill, and most Americans have no curbside scrap pickup.
• Washington wants to stop counting. EPA has proposed ending emissions reporting for 46 industries, including municipal landfills. It’s hard to plug a leak you’ve decided not to measure.

So where does that leave us? With proof that fixing the system does work.

When Massachusetts banned large businesses from landfilling food scraps, food rescue grew more than 50 percent and the state kept 3,300 tons of methane out of the air each year. Japan has managed to cut its food waste 31 percent. Yet only 21 countries even mention food waste in their climate plans. One of the biggest climate solutions we have is sitting on the table.

Food Waste Prevention Week runs September 28 through October 4. Join us as we clean out our fridges and clean up the rules that keep filling the landfill.