Calculating CO2 Offset and KM to compensate

Greenhouse gas emissionsper PMT for commuter transport options. (Life Cycle Assessmentof Transportation Options for Commuters (MIT) 2010)

The diagram shows greenhouse gas emissions as GGE in grams per person mile travelled as PMT. While most obvious polution will orgin on operation, e.g. fuel consumption on motorized vehicles) this calculation will also take into account: manufacturing, maintenance, etc.

GGE includes gases relevant for global climate change like: carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and fluorinated gases.

PMT allowes to take into account that some vehicle are more effective if they are heavaly used but as well not if they are used of peak.

Values considered and converted to KM:

  • Cycling: 33 gram per Mile, 21 gram per KM
  • Car (Sedan): 382 gram per Mile, 237 gram per KM
  • Train: avg(BART, MUNI, Green Line) = 178 gram per Mile, 110 gram per KM
  • Bus: avg 326 gram per Mile, 202 gram per KM

Sample UseCase “white longsleve T-Shirt”

Follwed values varies for sure between producers and resellers and are an estimation. As well the way how to handle the laundry or even where the power is comming from impacts this calculation. Thus the calcuation of laundry washing is on a base like:

Washing machine yearly GGE 118kg / 3 processes per week / 52 weeks = 0.76kg per process

CategoryOperationapprox. GGE (kg)
UsageWashing (Lifecycle 3 years, means 100 washing processes,
9 other clothes in machine drum – 1/10)
Approximation of a T-Shirt’s GGE footprint
Chart for GGE per km traveled per person


Questions should be and in it’s order:

  1. If it is broken, can it be repaired?
  2. Do I really need- what I’m about to order?
  3. Can anything else, I already have, do the job?
  4. Does anyone around me already have it, so can I borrow it?
  5. Is it sustainable produced and repairable, ethical?


Life Cycle Assessment of Transportation Options for Commuters. Shreya Dave, Massachusetts Institute of Technology (MIT). February 2010.

Carbon Footprint of Textile and Clothing Products. Handbook of Sustainable Apparel Production. Sohel Rana, Subramani Pichandi, Shabaridharan Karunamoorthy, Amitava Bhattacharyya, Shama Parveen, and Raul Fangueiro.

The hidden impact of your daily water use. Christine Ro. 27th March 2020.

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