Estimate your household's annual greenhouse gas emissions based on your energy consumption and travel habits.
Therms
Cubic Feet
–.– kg CO2e
Your estimated annual greenhouse gas emissions
Understanding Greenhouse Gas Emissions
Greenhouse gases (GHGs) are gases that trap heat in the Earth's atmosphere, contributing to climate change. Common GHGs include carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). This calculator provides an estimate of your household's annual emissions, primarily focusing on CO2 equivalents (CO2e), which is a standard unit for comparing the global warming potential of different GHGs.
Calculation Methodology
This calculator uses simplified emission factors for common household activities. The calculations are based on the following:
Electricity Emissions: This depends on the carbon intensity of your local electricity grid. For simplicity, we use a regional average emission factor. The formula is:
Annual Electricity Usage (kWh) * Electricity Emission Factor (kg CO2e/kWh)
(A common US average factor is around 0.45 kg CO2e/kWh, but this varies significantly by region.)
Natural Gas Emissions: Natural gas combustion produces CO2. The formula depends on the unit used:
If using Therms: Annual Natural Gas Usage (therms) * Natural Gas Emission Factor (kg CO2e/therm) (Approx. 5.3 kg CO2e/therm)
If using Cubic Feet: Annual Natural Gas Usage (cu ft) * Natural Gas Emission Factor (kg CO2e/cu ft) (Approx. 0.053 kg CO2e/cu ft)
Vehicle Emissions: Emissions from gasoline combustion. The formula is:
(Annual Vehicle Mileage / Vehicle Fuel Efficiency) * Gasoline Emission Factor (kg CO2e/gallon)
(A common factor for gasoline is around 8.89 kg CO2e/gallon, and a typical car emits about 19.6 lbs or 8.89 kg of CO2 per gallon of gasoline consumed.)
Flight Emissions: Air travel is a significant source of GHGs. This calculation uses an average emission factor per passenger-mile for a short-to-medium haul flight. The formula is:
Number of Flights * Average Flight Distance (miles) * Average Flight Emission Factor (kg CO2e/passenger-mile)
(We'll use an approximation of 1000 miles per flight and 0.15 kg CO2e/passenger-mile for this calculator.)
Total Emissions = Electricity Emissions + Natural Gas Emissions + Vehicle Emissions + Flight Emissions
Disclaimer
This calculator provides an estimate for educational and awareness purposes. Actual emissions can vary based on factors like the specific type of vehicle, exact flight routes, the fuel source for electricity generation in your specific area, and home heating/cooling efficiency. For precise calculations, consult specialized tools or professional assessments.
function calculateEmissions() {
var electricityUsage = parseFloat(document.getElementById("electricityUsage").value);
var naturalGasUsage = parseFloat(document.getElementById("naturalGasUsage").value);
var naturalGasUnit = document.getElementById("naturalGasUnit").value;
var vehicleMileage = parseFloat(document.getElementById("vehicleMileage").value);
var vehicleFuelEfficiency = parseFloat(document.getElementById("vehicleFuelEfficiency").value);
var flightsPerYear = parseFloat(document.getElementById("flightsPerYear").value);
var totalEmissions = 0;
var resultElement = document.getElementById("result");
// Emission Factors (kg CO2e)
var electricityFactor = 0.45; // kg CO2e per kWh (US Average, can vary significantly)
var naturalGasFactorTherms = 5.3; // kg CO2e per therm
var naturalGasFactorCubicFeet = 0.053; // kg CO2e per cubic foot
var gasolineFactor = 8.89; // kg CO2e per gallon of gasoline
var flightFactorPerMile = 0.15; // kg CO2e per passenger-mile (approximate)
var averageFlightDistance = 1000; // miles
// Calculate Electricity Emissions
if (!isNaN(electricityUsage) && electricityUsage >= 0) {
totalEmissions += electricityUsage * electricityFactor;
}
// Calculate Natural Gas Emissions
if (!isNaN(naturalGasUsage) && naturalGasUsage >= 0) {
if (naturalGasUnit === "therms") {
totalEmissions += naturalGasUsage * naturalGasFactorTherms;
} else { // cubicFeet
totalEmissions += naturalGasUsage * naturalGasFactorCubicFeet;
}
}
// Calculate Vehicle Emissions
if (!isNaN(vehicleMileage) && vehicleMileage >= 0 && !isNaN(vehicleFuelEfficiency) && vehicleFuelEfficiency > 0) {
var gallonsConsumed = vehicleMileage / vehicleFuelEfficiency;
totalEmissions += gallonsConsumed * gasolineFactor;
}
// Calculate Flight Emissions
if (!isNaN(flightsPerYear) && flightsPerYear >= 0) {
totalEmissions += flightsPerYear * averageFlightDistance * flightFactorPerMile;
}
// Display Result
if (totalEmissions > 0) {
resultElement.innerHTML = totalEmissions.toFixed(2) + " kg CO2eYour estimated annual greenhouse gas emissions";
} else {
resultElement.innerHTML = "–.– kg CO2eEnter valid data to calculate";
}
}