Which Intergovernmental Panel on Climate Change defaults turn a tonne of factory waste sent to a dump into methane: carbon content, site type and decay rate?

For waste sent to a dump, the Intergovernmental Panel on Climate Change (IPCC) 2006 sets degradable organic carbon (DOC) at 15 percent of wet food waste, 24 for textile, 40 for paper and 43 for wood. A site-type factor of 0.4 to 1.0 and a decay rate then spread the methane (CH4) over years.

Carbon in process waste, by industry

• Table 2.5, per cent of wet waste, as DOC, fossil carbon, total carbon, then water: food, beverages and tobacco (other than sludge) 15, none, 15, 60; textile 24, 16, 40, 20; wood and wood products 43, none, 43, 15; pulp and paper (other than sludge) 40, 1, 41, 10.
• Petroleum products, solvents and plastics: no DOC, 80 fossil, 80 total, 0 water. Rubber (39), 17, 56, 16, where the DOC is bracketed because natural rubber would likely not degrade without air. Construction and demolition 4, 20, 24, 0. Other 1, 3, 4, 10.
• The guide says these defaults apply only to process waste, with office and similar waste assumed to be in municipal waste, and that they are very uncertain. It adds that water content varies enormously even within one industry.

From carbon to methane: four more defaults

• Share of the DOC that can decompose (DOCf): 0.5, on the assumption that the site is anaerobic and the DOC values include lignin.
• Site type correction factor (MCF), Table 3.1: managed and anaerobic 1.0; managed and semi-aerobic 0.5; unmanaged, deep (more than 5 metres of waste) or with a high water table 0.8; unmanaged and shallow (under 5 metres) 0.4; site not categorised 0.6. The guide explains that in an unmanaged site a larger share decomposes aerobically in the top layer, and less in a deep one, which is why the shallow figure is lowest.
• Share of CH4 in the landfill gas (F): 0.5. Oxidation in the cover (OX): 0 by default, and 0.1 for a covered, well-managed site.
• Equations 3.2 and 3.3 multiply these. Decomposable carbon is waste tonnes times DOC times DOCf times MCF. The lifetime CH4 potential is that carbon times F times 16/12.

How fast it comes out

Equations 3.4 and 3.5 use a decay constant k. The share of the decomposable carbon that decomposes in a year is 1 minus e to the power minus k. Tropical defaults (mean annual temperature above 20 degrees Celsius), dry then moist and wet: paper and textiles 0.045 and 0.07; wood and straw 0.025 and 0.035; other organic waste and garden waste 0.065 and 0.17; food waste and sewage sludge 0.085 and 0.4; bulk waste 0.065 and 0.17. Half-lives for food waste are 8 years dry and 2 years moist and wet.

Dry here means mean annual rain under 1,000 millimetres and moist and wet means 1,000 or more. The guide says the values for tropical conditions are indicative, because information there is limited. It also says the climate should be taken from the nearest representative weather station. Which zone your dump is in is your call.

100 tonnes of process waste to an unmanaged deep dump (example quantity)

• Food waste: 100 x 0.15 x 0.5 x 0.8 = 6.0 tonnes of decomposable carbon. Lifetime CH4: 6.0 x 0.5 x 16/12 = 4.0 tonnes
• Textile: 100 x 0.24 x 0.5 x 0.8 = 9.6 tonnes of carbon, lifetime CH4 6.4 tonnes
• Paper: 100 x 0.40 x 0.5 x 0.8 = 16.0 tonnes of carbon, lifetime CH4 10.67 tonnes. Wood: 100 x 0.43 x 0.5 x 0.8 = 17.2 tonnes, lifetime CH4 11.47 tonnes
• Food waste with k = 0.4 (tropical, moist and wet): the share decomposing in the year after deposit is 1 minus e to the power minus 0.4 = 0.33, so 4.0 x 0.33 = 1.32 tonnes of CH4
• At an example global warming potential of 28, the 4.0 tonnes of food waste CH4 are 112 tonnes of carbon dioxide equivalent over the long run

The 100 tonnes, the site type and the global warming potential are example values. Textile and rubber waste also hold fossil carbon. Our reading is that this matters when the waste is burnt, because the dump method in the guide runs on DOC. The guide says reported degradability varies over a wide range, especially for wood.

What Senseible does here

Senseible reads fuel invoices and electricity bills into monthly records, so diesel and power at your own plant show up once uploaded. Waste tonnes by type come from your gate passes and the dump or hauler's slips, which you add.

• Methane from a municipal landfill
• Food waste: landfill, compost or biogas
• Waste from your operations: Scope 3 Category 5
• Free calculators

Sources: IPCC 2006 Guidelines, Volume 5 chapter 2: Waste Generation, Composition and Management Data (Tables 2.4 and 2.5), IPCC 2006 Guidelines, Volume 5 chapter 3: Solid Waste Disposal (Equations 3.1 to 3.6, Tables 3.1 to 3.4)

Last reviewed 2026-11-05. Defaults are from the 2006 IPCC Guidelines and are marked by the guide as very uncertain for industrial waste. Confirm with your verifier which site type and climate zone you use.