Forest Fire Emissions Calculator
Compute forest fire emissions using validated scientific equations. See step-by-step derivations, unit analysis, and reference values.
Reviewed by Daniel Agrici, Founder & Lead Developer
Formula
Emissions = Area x Biomass x Combustion Factor x Emission Factor
CO2 = area x biomass x combustion factor x carbon fraction x 44/12. CH4 and N2O use emission factors in g/kg. GWP: CH4=28, N2O=265.
Worked Examples
Example 1: Boreal Forest Wildfire
Problem:A wildfire burns 2,000 ha of boreal forest, 120 t/ha biomass, CF 0.40, carbon fraction 0.47, CH4 5.5 g/kg.
Solution:Biomass = 240,000 t\nConsumed = 96,000 t\nCO2 = 165,440 t\nCH4 = 528 t (14,784 t CO2e)\nN2O = 19.2 t (5,088 t CO2e)\nTotal = 185,312 t CO2e
Result:Total CO2e = 185,312 t | CO2 = 165,440 t | CH4 = 528 t
Example 2: Tropical Deforestation Fire
Problem:100 ha tropical forest, 300 t/ha, CF 0.55, carbon 0.47, CH4 6.8 g/kg.
Solution:Consumed = 16,500 t\nCO2 = 28,435 t\nCH4 = 112.2 t (3,142 t CO2e)\nN2O = 3.3 t (875 t CO2e)\nTotal = 32,451 t CO2e
Result:Total = 32,451 t CO2e | 324.5 t/ha
Frequently Asked Questions
How are forest fire emissions calculated?
Forest fire emissions are calculated using the IPCC approach: Emissions = Burned Area x Fuel Load x Combustion Factor x Emission Factor. The burned area is measured in hectares using satellite data or ground surveys. Fuel load is the biomass density in tonnes per hectare. The combustion factor represents the fraction of biomass consumed by fire, typically 0.2 to 0.6. Emission factors convert consumed biomass to specific greenhouse gases. This method is used globally for national greenhouse gas inventories.
Why do forest fires produce methane and not just CO2?
Forest fires produce methane and other non-CO2 gases due to incomplete combustion. When biomass burns with sufficient oxygen, it produces primarily CO2 and water vapor. However, smoldering combustion in logs, duff layers, and soil organic matter occurs at lower temperatures with limited oxygen, producing significant CH4, carbon monoxide, and volatile organic compounds. Typical forest fires emit about 4 to 9 grams of CH4 per kilogram of dry fuel burned. Though CH4 is a small fraction by mass, its global warming potential is 28 times that of CO2.
How much CO2 do forest fires emit globally each year?
Global forest and vegetation fires emit approximately 5 to 8 billion tonnes of CO2 per year, varying significantly with annual fire activity. Savanna and grassland fires account for about 60 percent of global burned area but have lower fuel loads. Tropical deforestation fires in the Amazon, Indonesia, and Central Africa are particularly significant. Boreal forest fires in Russia and Canada have been increasing in frequency due to climate change. In extreme fire years, single events can release over 400 million tonnes of CO2.
Are forest fire CO2 emissions counted as net emissions?
The accounting depends on whether the forest regrows. In natural fire regimes, CO2 emissions from fire are considered roughly carbon-neutral over decades because regrowing vegetation reabsorbs the released carbon. However, when fire leads to permanent deforestation or land conversion, the emissions are counted as net additions to the atmosphere. Climate change is increasing fire frequency and severity in some regions, potentially exceeding the capacity of forests to recover, which could shift fire emissions from carbon-neutral to net positive.
References
Reviewed by Daniel Agrici, Founder & Lead Developer · Editorial policy