Waste and Biogas Carbon Credits: Methane Capture Explained

Landfill gas, biogas digesters, composting and waste-to-energy: why cutting methane earns credits, how the gas is metered, and the checks a buyer should run.

Rotting waste is one of the quieter sources of climate pollution. Food scraps in a municipal dump, cattle dung in a heap, effluent from a sugar mill or distillery: left to decompose without air, they release methane. Projects in our Waste & Biogas category earn credits by capturing that methane and burning it, or by stopping it forming in the first place.

Why methane matters

Methane traps far more heat than carbon dioxide while it stays in the atmosphere. Over a 100-year horizon, the comparison most carbon methodologies use, one tonne of methane counts as several dozen tonnes of CO₂ equivalent. That multiplier is why a modest amount of captured gas can produce a meaningful volume of credits, and why cutting methane is one of the fastest ways to slow warming in the near term.

When captured methane is burned, in a flare or an engine, it turns into CO₂ and water. The CO₂ released is far less harmful than the methane would have been, and if the gas generates power or replaces cooking fuel, there is a second saving from the fossil energy displaced.

How the credits are created

The category covers several activity types:

Landfill gas capture. Wells and pipes collect gas from a closed or active landfill and send it to a flare or a gas engine.
Biogas digesters. Sealed tanks break down dung, crop residue or food waste without air and collect the gas for cooking, heating or power. They range from household units on dairy farms in Maharashtra or Karnataka to large plants at dairies and food factories.
Industrial wastewater. Open lagoons at distilleries, starch plants or palm oil mills are covered and the methane captured.
Composting. Organic waste is composted with air instead of being dumped, so far less methane forms.
Waste-to-energy. Waste is processed into fuel or power, avoiding both landfill methane and some fossil generation.

For capture projects, the core measurement is simple in principle: how much gas went to the flare or engine, and how much of it was methane. Flow meters and gas analysers record this continuously, and flare temperature or engine run-hours show the gas was actually destroyed. For household digesters and composting, the volume is estimated from the amount of waste treated, with sample surveys to confirm units are working.

What a buyer gets

Most of these credits are reductions: methane destroyed or avoided compared with the baseline. Where power or cooking fuel is displaced, part of the volume is avoidance. They are not removals. The listing's project type field shows how the project is classified.

The main quality questions

Regulatory surplus

If the law already requires a landfill to capture and flare its gas, doing so is not additional. In India, waste management rules set requirements for how cities handle municipal waste, and enforcement varies. Ask whether capture or treatment is mandated for this site and, if so, how the project goes beyond the requirement. Our page on additionality, permanence and leakage explains the wider tests.

Monitoring quality

Gaps in meter data, uncalibrated analysers or flares running cold all reduce the true reduction. Ask for the monitoring report covering the vintage you are buying, and look for the calibration records and how missing data was handled. Conservative methodologies assume no destruction during periods without data.

For digesters, are they still working?

Household biogas units can fail through leaks, lack of dung or poor maintenance. Ask what share were found operational at the last verification and what support families receive.

Baseline methane estimates

For composting and waste-to-energy, credits rest on modelling how much methane the waste would have produced in a dump over many years. Check which model was used and whether the waste composition data comes from the site or from defaults.

Permanence

Once methane is destroyed it cannot come back, so reversal risk is low. The risk lies instead in over-estimating how much was destroyed.

Co-benefits

Capturing landfill gas reduces odour, fire risk and local air pollution around dumpsites, a real concern for neighbourhoods near large Indian landfills. Biogas gives rural families clean cooking fuel and produces slurry that farmers use as fertiliser. Composting returns organic matter to soils. SDG tiles here often include Sustainable Cities (SDG 11), Affordable and Clean Energy (SDG 7) and Good Health (SDG 3). Our article on SDGs and co-benefits explains how to test the claims behind them.

What to ask the seller

Question	What a good answer looks like
Which activity and methodology?	Registry ID and methodology version, matched to the registry entry
Is capture or treatment legally required at this site?	A clear explanation of the regulation and how the project exceeds it
How is destruction metered?	Continuous flow and methane readings, flare or engine logs, calibration records
How was missing data treated?	Conservative assumptions, stated in the monitoring report
For digesters, what share are working?	A survey result from the latest verification
Is any power or fuel also sold with environmental certificates?	Written confirmation of no double claim

Our guide to project documents buyers receive shows where each answer usually sits in the paperwork.

On this marketplace

Waste and biogas listings carry the registry, methodology, vintage and delivery type, along with issued volumes to date, which gives a quick sense of a project's track record. Start with the Waste & Biogas category; if you need help comparing two methane projects, contact the desk and we will go through the monitoring reports with you.