Annam Naturals
Sustainable Kitchen & Food

Food waste and methane: why COP31 is talking about your leftovers

Rotting food in landfill releases methane, a powerful greenhouse gas. That is why food waste is on the climate agenda this year.

2 October 2026 · 8 min read

A bag full of orange peels collected for composting

Chetanya Goel · Founder & Editor

Chetanya started Annam Naturals after two years of keeping a household waste diary. Chetanya writes about the boring, repeatable habits that hold up in a real week.

The UN's International Day of Zero Waste in March 2026 took food waste as its theme, framed explicitly as a lead-up to COP31 in Antalya. It is not a coincidence. Food waste has moved from a household issue to a climate one, and methane is the reason.

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Why methane matters

Methane is a greenhouse gas that traps far more heat than carbon dioxide over the short term, though it breaks down faster in the atmosphere. That makes cutting methane one of the quickest ways to slow warming in the coming decades. Landfills are a major source, largely because food and other organic waste rot there without oxygen.

How big is food waste?

The UN Environment Programme's Food Waste Index has found that households account for the largest share of global food waste, more than restaurants or shops. Every kilogram of wasted food also carries the emissions of growing, transporting and cooking it.

What happens to your food scraps

In a landfill, food rots in conditions that produce methane. In a compost pile with air, it breaks down mainly into carbon dioxide, water and useful compost, with far less methane. In a biogas plant, the methane is captured and used as fuel. So where your scraps go matters as much as how much there is.

What a household can do

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  • Waste less to begin with: plan meals, store food well, and cook what you have
  • Separate wet waste so it can be composted or sent to biogas
  • Compost at home or in your building if you can
  • Support municipal wet-waste collection by keeping it free of plastic

Our earlier articles on cooking from the back of the fridge, storing vegetables without plastic and composting in a small apartment cover these steps in detail.

What to watch at COP31

Look for announcements on methane from waste and agriculture, and on food systems more broadly. Many countries have included waste and methane in their climate plans, and progress here is relatively quick and cheap compared with other sectors.

The household link

Of all the big topics discussed at a climate summit, food waste is the one most directly in our own hands. A fridge that is used well and a wet-waste bin that goes to compost are small, daily contributions to one of the fastest climate wins available.

For more of this kind of testing, the sustainable kitchen & food hub collects everything we've tried in that area.

Frequently asked

Do I need to buy anything to get started?

No. Every method here begins with what is already in your cupboards. We only recommend a purchase when something has genuinely worn out, and we say what it should cost.

How do you test the things you write about?

Minimum four weeks of ordinary household use, with notes. For anything involving energy or money we use a plug-in meter and record the readings before and after.

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What if a method doesn't work in my home?

Write to us. A surprising amount of our best material comes from readers explaining why something failed in a flat, a shared house or a very cold winter.

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