Methane, landfills and the climate cost of waste

When we bury our rubbish, it doesn't just disappear. Beneath the surface, landfills are quietly producing one of the most potent greenhouse gases on the planet: methane. Understanding this hidden climate cost reveals why diverting waste from landfill is such an important climate action.

What is methane and why does it matter?

Methane (CH₄) is a greenhouse gas. While carbon dioxide gets most of the attention, methane is far more potent at trapping heat — many times more powerful than CO₂ over a 20-year period. The upside is that methane is also relatively short-lived in the atmosphere, which means cutting methane emissions delivers fast climate benefits. Tackling methane is one of the quickest ways to slow warming.

How landfills produce methane

Here's the chemistry, simply. When organic waste — food scraps, garden waste, paper — is buried in a landfill, it's compacted and covered, cutting off oxygen. Microbes then break it down anaerobically (without oxygen), and this process releases methane.

The key insight: it's the organic material in landfill that generates methane. The more food and garden waste we bury, the more methane our landfills produce.

The scale of the problem

Landfills are a significant source of human-caused methane emissions worldwide. Because so much of what we bury is organic, waste is a meaningful contributor to the methane problem — and therefore to climate change. For a city like Cape Town, with large volumes of waste going to landfill, the climate footprint of waste is substantial.

The double benefit of diversion

Here's the good news: keeping organic waste out of landfill tackles two problems at once.

1. It cuts methane. Composting organics aerobically (with oxygen) produces far less methane than burying them.
2. It saves landfill space. Organics are a huge share of the waste stream, so diverting them dramatically extends landfill life.

Add the energy savings from recycling other materials, and waste diversion becomes one of the most effective climate actions in the whole waste sector.

What about capturing landfill gas?

Some landfills capture methane (landfill gas) and even use it to generate energy, which is far better than letting it escape. But capture is never complete — a lot of methane still leaks — and it's a way of managing a problem rather than preventing it. The better solution is to keep the methane-producing organic material out of landfill in the first place.

How recycling and composting help

• Composting food and garden waste avoids the anaerobic decomposition that creates landfill methane.
• Recycling paper keeps another organic material out of landfill.
• Recycling all materials reduces the energy and emissions of making new products.
• Reducing waste overall means less to bury and less methane produced.

Together, these shrink the climate cost of our waste significantly.

What you can do

The fight against methane starts in your kitchen:

• Compost your food and garden waste — the single most impactful thing for landfill methane.
• Recycle your paper rather than binning it.
• Reduce food waste — wasted food that's never produced means no emissions at all.
• Separate and recycle all your materials.
• Support diversion efforts in your community.

A fast climate win

Because methane is so potent but short-lived, reducing it offers some of the quickest climate benefits available. And because organic waste is such a major methane source, diverting it from landfill is a climate action with outsized impact — one that ordinary households can take today through composting and recycling.

The next time you compost your peels or recycle your paper, know that you're cutting one of the most powerful greenhouse gases at its source. To divert and recycle the rest of your waste, partner with WasteGo Green.