Greenhouse Gas Calculator Formula

Understand the math behind the greenhouse gas calculator. Each variable explained with a worked example.

Use the Greenhouse Gas Calculator

Formulas Used

Total CO2 Equivalent

total_co2e = co2_tons + ch4_co2e + n2o_co2e

Methane as CO2e

ch4_share = ch4_co2e

N2O as CO2e

n2o_share = n2o_co2e

Non-CO2 Share

pct_non_co2 = (ch4_co2e + n2o_co2e) / (co2_tons + ch4_co2e + n2o_co2e) * 100

Variables

VariableDescriptionDefault
co2_tonsCO2 Emissions(metric tons)100
ch4_tonsMethane (CH4) Emissions(metric tons)5
n2o_tonsNitrous Oxide (N2O) Emissions(metric tons)1
ch4_co2eDerived value= ch4_tons * 28calculated
n2o_co2eDerived value= n2o_tons * 265calculated

How It Works

How to Calculate Greenhouse Gas Equivalents

Different greenhouse gases have different warming potentials. Converting to CO2-equivalent (CO2e) allows comparison.

Global Warming Potentials (GWP-100)

  • CO2: 1x (baseline)
  • Methane (CH4): 28x
  • Nitrous Oxide (N2O): 265x

    • Formula

    Total CO2e = CO2 + (CH4 * 28) + (N2O * 265)

    Worked Example

    A facility emits 100 tons CO2, 5 tons CH4, and 1 ton N2O per year.

    co2_tons = 100ch4_tons = 5n2o_tons = 1
    1. 01CO2 contribution: 100 metric tons CO2e
    2. 02Methane: 5 * 28 = 140 metric tons CO2e
    3. 03Nitrous oxide: 1 * 265 = 265 metric tons CO2e
    4. 04Total: 100 + 140 + 265 = 505 metric tons CO2e
    5. 05Non-CO2 share: (140 + 265) / 505 * 100 = 80.2%

    Frequently Asked Questions

    What are the main greenhouse gases?

    The primary greenhouse gases are carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and fluorinated gases. CO2 accounts for about 76% of global emissions by weight but less when adjusted for potency.

    Why is N2O so potent?

    Nitrous oxide has 265 times the warming potential of CO2 over 100 years and persists in the atmosphere for about 114 years. Major sources include agriculture, industry, and fuel combustion.

    What does CO2e mean?

    CO2-equivalent (CO2e) is a standard metric that converts all greenhouse gases to the equivalent amount of CO2 with the same warming effect, enabling comparison across different gases.

    Ready to run the numbers?

    Open Greenhouse Gas Calculator