Calculate - aurimasmb/carbonoffsets GitHub Wiki

Accurately calculating the carbon footprint you wish to offset is vital and challenging. For the most part, you can trust the calculators built into the providers. This page is for those interested in learning more about how carbon footprints are calculated, especially for flights.

Carbonfootprint.com has a decent explanation. The baseline emissions for a flight are calculated based on the type of flight/plane and the distance traveled. An 8% bump is added to account for planes not often taking the most direct route (avoiding international airspace, etc.). The calculation for your personal share of that flight is based on the seat you have (First or Economy) and average plane occupancy numbers. Sometimes, a factor of 1.9 is used to account for Radiative Forcing (basically, high altitude emissions are more powerful than low-altitude ones). This factor comes from the UK's DEFRA.

The UK government has provided standard guidance for calculating emissions associated with various activities.

Online Calculators

Many websites exist to help you calculate your carbon footprint, which you can then partially or fully offset. Most of our recommended providers also have calculators built in.

Calculator	Emissions Types	Notes	Methodology
Climate Care	Flight, Car, Domestic Energy Use, Event	Nice calculator. You can easily see your total carbon emissions on the basket page.	Methodology
BP Target Neutral	Flight, Car, Coach Train, Tube, Tonnes	Slightly annoyingly doesn't show a total CO2 emissions for all journeys. However, you can easily back-calculate this from the price of CO2 offsets provided.	Methodology
Carbon Footprint	Flights, Car, Motorcycle, Various Public Transport, Domestic Energy Use, Embodied Energy of Common Products	Annoyingly only allows 3 flight legs. Results don't show individual flights or other itemized contributions. Not recommended.	Various Sources (Listed on Calculator page.) Not clear how values are chosen for each calculation, because no detailed methodology provided.
ICOA	Flights	Annoyingly doesn't allow you to change the origin airport on flights after the first leg has been added.	Methodology
Climate Neutral Now	Various Transport, Household Waste, Domestic Energy	Generally just a really crappy design. Wouldn't trust this.	Various sources listed. No detailed methodology.
MyClimate	Flights, Various Transport, Domestic Energy,	Seems fine for flights at least. You have to click through to add things to basket before you can see totals.	Methodology
CarbonBalanced.Org	Flights, Various Transport, Domestic Energy, Tonnes	Seems fine.	Uses UK Gov Standard Guidance

Discussion

All current publicly accessible carbon footprint web calculators seem to suffer from one or more of the following problems:

Are created by a company with vested interest in users purchasing more carbon offsets.
Use annoying captive interfaces.
Don't output data in machine-readable + human-readable format (i.e. JSON) which could be manipulated by other tools.
Sometimes don't provide clear sources for values used.
Aren't open-source.

Auri would love to find an open-source tool which sources standard government data and allows for simple machine and human interfacing with this data and established calculation methods.

If no such tool yet exists, would be nice if someone made one.

Calculate - aurimasmb/carbonoffsets GitHub Wiki

Online Calculators

Discussion

Further Reading