How far off can the Intergovernmental Panel on Climate Change default carbon dioxide factor be for diesel, liquefied petroleum gas (LPG), coal, petcoke or wood?

The Intergovernmental Panel on Climate Change (IPCC) 2006 Table 1.4 prints a 95% range around each default carbon dioxide (CO2) factor per terajoule (TJ). Diesel runs from 2.0% below to 0.9% above its default. Petroleum coke runs 15.0% below to 17.9% above, and wood 15.2% below to 17.9% above.

What the range is built from

• Each range is a 95% confidence interval: the lower limit is the 2.5th percentile and the upper limit the 97.5th percentile of the distribution IPCC fitted.
• For wood, charcoal and other primary solid biomass, IPCC's footnotes say the ranges are expert judgement, not fitted to data. The rows below marked (expert judgement) are those.
• IPCC calculated the Table 1.4 ranges from the carbon content ranges (Table 1.3) and the net calorific value ranges (Table 1.2) with a Monte Carlo analysis of 5,000 iterations.
• So the range reflects how fuel quality varies. It does not include errors in your own litres or tonnes. IPCC treats activity data uncertainty separately. That reading of the scope is mine.

The ranges for fuels Indian plants burn

Default in kilograms (kg) CO2 per TJ, then the 95% range, then the range as a share of the default. Percentages are my arithmetic on IPCC's printed figures.

• Gas and diesel oil: 74,100; 72,600 to 74,800; 2.0% below to 0.9% above.
• Motor gasoline: 69,300; 67,500 to 73,000; 2.6% below to 5.3% above.
• Liquefied petroleum gases: 63,100; 61,600 to 65,600; 2.4% below to 4.0% above.
• Natural gas: 56,100; 54,300 to 58,300; 3.2% below to 3.9% above.
• Residual fuel oil: 77,400; 75,500 to 78,800; 2.5% below to 1.8% above.
• Other kerosene: 71,900; 70,800 to 73,700; 1.5% below to 2.5% above.
• Other bituminous coal: 94,600; 89,500 to 99,700; 5.4% either way. Sub-bituminous coal: 96,100; 92,800 to 100,000; 3.4% below to 4.1% above.
• Lignite: 101,000; 90,900 to 115,000; 10.0% below to 13.9% above. Coke oven coke: 107,000; 95,700 to 119,000; 10.6% below to 11.2% above.
• Petroleum coke: 97,500; 82,900 to 115,000; 15.0% below to 17.9% above.
• Wood and wood waste, and charcoal: 112,000; 95,000 to 132,000 (expert judgement); 15.2% below to 17.9% above. Other primary solid biomass: 100,000; 84,700 to 117,000 (expert judgement); 15.3% below to 17.0% above.

What the pattern tells you

• The liquid and gas fuels listed above sit within about 3.2% below and 5.3% above their default. My reading is that a named IPCC default is a reasonable choice for those fuels, though IPCC's table has other liquid and gas lines with wider ranges.
• Coal is wider, and lignite, coke, petcoke and biomass are widest, at 10 to 18%. That is where a fuel test earns its cost.
• These are per TJ. If you start from tonnes, you also use a net calorific value, and its range is wide for the same solid fuels: petroleum coke 29.7 to 41.9 TJ per gigagram around 32.5, lignite 5.50 to 21.6 around 11.9, wood 7.90 to 31.0 around 15.6 (the wood range is expert judgement). Per tonne, the spread is larger than the table above suggests.
• IPCC says a country-specific factor that falls inside the range could be regarded as consistent with the default. The lab-factor answer shows how to test your own.

Two fuels at the default heat value, with the 95% range

• Petroleum coke, 1,000 tonnes at 32.5 gigajoules (GJ) per tonne = 32.5 TJ
• Default: 32.5 x 97,500 = 3,168,750 kg = 3,168.75 t CO2
• Lower limit: 32.5 x 82,900 = 2,694.25 t. Upper limit: 32.5 x 115,000 = 3,737.5 t
• Diesel, 100 tonnes at 43.0 GJ per tonne = 4.3 TJ
• Default: 4.3 x 74,100 = 318.63 t. Lower: 4.3 x 72,600 = 312.18 t. Upper: 4.3 x 74,800 = 321.64 t

The heat values 32.5 and 43.0 are IPCC's Table 1.2 defaults, held fixed here. A real batch of petcoke or diesel will have its own heat value, which moves the answer too.

What Senseible does here

Senseible reads fuel invoices and electricity bills into monthly records. A named default factor is fine for diesel and gas. For petcoke, lignite or biomass, ask your supplier for a heat value report and keep it beside the records.

• Will a buyer accept IPCC Tier 1 factors?
• Is my lab CO2 factor within the IPCC range?
• Pet coke emission factor in India
• How to estimate inventory uncertainty

Sources: IPCC 2006 Guidelines, Volume 2, Chapter 1 (Tables 1.2, 1.3 and 1.4, and section 1.5 on uncertainty)

Last reviewed 2026-11-05. The 2006 default tables are still the ones most Indian buyers name. Check whether your buyer asks for the 2019 Refinement before relying on these ranges.