Food waste methane emissions: Why your bin choice matters

Rachel Stirrup

February 11, 2025

Does your food bin fuel climate change?

When clearing out the fridge for a new week’s groceries, it’s tempting to throw leftovers straight into the bin. But did you know food waste methane emissions are one of the biggest hidden contributors to climate change?

By simply putting food scraps in the wrong bin, we may be fuelling greenhouse gas emissions—thanks to microbes and methane. This blog explains how food waste generates methane, why landfills are a problem, and how small changes at home can make a big environmental difference.

Methane unmasked: Why it’s so harmful

Methane is a powerful greenhouse gas. Over a 20-year period, it is 84 times more potent than carbon dioxide at trapping heat in the atmosphere.

In the UK, around 22% of total methane emissions come from landfill sites, largely due to decomposing organic waste like food.

Learn more about methane and climate change from the IPCC

Meet the microbes behind methane

Our environment is full of microbes that play essential roles in recycling nutrients such as carbon and nitrogen. However, landfill sites create ideal conditions for a specific group of microbes called methanogens.

Methanogens thrive in anaerobic (oxygen-free) environments, making buried food waste the perfect fuel source for methane production.

The problem with food waste in landfill

Food waste doesn’t break down quickly in landfill. Instead, it decomposes slowly over several years through a complex microbial process.

Towards the final stages, methanogens begin methanogenesis, consuming organic matter and producing methane gas. The more food waste sent to landfill, the greater the methane emissions released into the atmosphere.

Methanogens themselves aren’t the enemy—they support natural processes in extreme environments on Earth, and some scientists even believe they could exist on Mars. The real issue is too much food waste ending up in landfill.

Small changes, big impact: Reducing food waste at home

The most effective way to cut food waste methane emissions is to waste less food in the first place. Each year, UK households throw away over 4 million tonnes of food.

Here’s how you can help:

• Plan meals and store food properly
• Use leftovers creatively (soups, stir-fries, sandwiches)
• Freeze food before it spoils
• Avoid putting food waste in general rubbish bins

Composting: A sustainable solution for food waste

When food waste is collected separately, it is typically composted in industrial facilities. The resulting compost can be used in agriculture or gardening, returning nutrients to the soil.

A recent study found that composting food waste produces 38–84% fewer methane emissions compared to landfill decomposition.

Take action: Use the right bin

Next time you’re scraping leftovers into the bin, think about those methanogens quietly producing methane underground. Using a food waste bin or kitchen caddy instead can significantly reduce greenhouse gas emissions.

To find out what food waste collections are available near you, visit the Recycling Locator and search for “Food waste” with your postcode.

Key takeaways: Why food waste recycling matters

• Food waste in landfill produces methane, a powerful greenhouse gas
• Methane emissions significantly accelerate climate change
• Composting food waste drastically reduces methane production
• Small household changes can have a large environmental impact

Choosing the right bin for your food waste is one of the simplest ways to help protect the planet.

Disclaimer: The opinions expressed in this blog are those of the author, Rachel Stirrup, and do not necessarily reflect the views of Recycle More, Valpak Limited, or any other organisation.