About

This tool performs a rigorous assessment of personal or household Greenhouse Gas (GHG) emissions, quantified in kg CO₂e (Carbon Dioxide Equivalent). Unlike simplified calculators that use generic averages, this engine utilizes granular Emission Factors (EF) derived from global standards (EPA, DEFRA) to account for vehicle efficiency, flight radiative forcing, and specific fuel calorific values.

Accurate carbon accounting is the prerequisite for effective offsetting. By converting energy consumption and travel distance into a unified mass of carbon, users can visualize their impact relative to the biosphere's absorption capacity (represented here by the mature tree year metric). The logic incorporates radiative forcing indices for aviation, acknowledging that high-altitude emissions have a compounding warming effect.

Formulas

The core calculation aggregates emissions across n categories using activity data and specific emission factors.

{

E_total = n∑i=1 (A_i × EF_i)

Where:

E_total = Total Emissions (kg CO₂e)

A_i = Activity data (e.g., km traveled or kWh consumed)

EF_i = Emission Factor for activity i

Offset Equivalence:

Trees = E_totalA_tree

Where A_tree ≈ 22 kg/year (absorption of a mature tree).

Reference Data

Source Activity	Emission Factor (EF)	Unit	Notes
Car (Petrol, Average)	0.192	kg CO₂e / km	Standard combustion engine efficiency
Car (Diesel, Average)	0.171	kg CO₂e / km	Lower CO2 per km, higher NOx (not calculated here)
Car (EV, Grid Mix)	0.053	kg CO₂e / km	Based on global avg grid intensity
Bus (City)	0.104	kg CO₂e / km	Per passenger, avg occupancy
Train (National)	0.041	kg CO₂e / km	Electric rail avg
Flight (Domestic < 500km)	0.255	kg CO₂e / km	Includes takeoff intensity & radiative forcing
Flight (Long Haul > 3700km)	0.150	kg CO₂e / km	Cruising efficiency per pax/km
Electricity (Grid Avg)	0.385	kg CO₂e / kWh	Global average baseline
Natural Gas	0.202	kg CO₂e / kWh	Direct combustion
Heating Oil	0.275	kg CO₂e / kWh	Domestic fuel oil

Frequently Asked Questions

Takeoff and landing require maximum thrust, consuming disproportionate amounts of fuel. For short flights (under 500km), this fuel burn is distributed over fewer kilometers, resulting in a higher per-km emission factor compared to cruising at altitude.

Aviation emissions at high altitudes (contrails, NOx, water vapor) create a warming effect greater than the CO2 alone. Our calculator applies a Radiative Forcing Index (RFI) of roughly 1.9x to 2.7x (depending on distance) to account for this total climate impact.

We use a conservative estimate of 22kg CO2 absorbed per year by a mature tree in a tropical zone. This helps visualize the biological effort required to sequester the emitted carbon over one year.

The default "Grid Average" factor (0.385 kg/kWh) represents a global mix of coal, gas, nuclear, and renewables. If you strictly use a certified Green Energy provider, your personal factor would be near zero (Wind/Solar), though infrastructure embodied carbon still exists.