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Lesson 5 of 9
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Lesson 5: Carbon Footprint Calculation Process and Examples​

Learning Outcomes 

By the end of this lesson, you should be able to:

  • Use knowledge from previous lessons to be able to interpret data into the carbon footprint categories and format
  • Understand how to use the MfE’s guidance document to calculate emissions
  • Be able to use raw data, and convert it to a carbon footprint for a range of emissions which present themselves across industry

Video Duration: 25 minutes approximately

Lesson Notes 

MfE’s Measuring Emissions Guide

  • Guide for measuring emissions, published by the Ministry for Environment
  • Includes emissions factors for a range of emissions sources across scopes
  • Includes methodology for deriving these emissions factors
  • Updated annually

For image see Reference Link 1.

GHG Inventory vs GHG Report

As defined by the MfE guidance document:

  • GHG Inventory contains all applicable emissions for an organisation within a defined boundary during a set period. A GHG inventory is key to measuring emissions.
  • GHG Report expands on the inventory with context about the organisation, methods used, as well as analysis of drivers and progress over time. A GHG report is key to reporting emissions.

Emissions Factors

Each emissions source has an associated UNIT, for example:

  • Coal: kg
  • Diesel: L
  • Electricity: kWh
  • Petrol/diesel/electric/hybrid vehicle: km
  • Bus and plane: pkm
  • Helicopter: hours
  • Upstream and downstream shipping: tkm etc

Emissions Factors

  • Example emissions factor from 2023 document, for employee’s personal petrol vehicles (which is part of Scope 3):

cep1014-lesson-5-petrol-vehicles-table

Calculating Emissions

E = Q * F

E = emissions from the emissions source in: kg CO2-e (per year)

Q = activity data, e.g. quantity of fuel used: units (per year)

F = emission factor for emissions source: kg CO2-e (per unit)

Following are calculation examples from some example emissions sources, across the three emissions scopes.

Trucking Emissions Example:

  • If the trucks are company-owned as in this example, they are scope 1 emissions
  • If they are owned by a 3rd party, these emissions would become upstream/downstream transport, which falls under scope 3

 

cep1014-lesson-5-trucking-emissions

Shipping Emissions Example 1:

cep1014-lesson-5-shipping-emissions

Shipping Emissions Example 2:

cep1014-lesson-5-shipping-emissions-example 2

Fleet Vehicle Emissions​ Example:

  • If the vehicles are company-owned, fleet emissions are scope 1 under mobile combustion

cep1014-lesson-5-fleet-vehicles-emissions

Employee Commuting Emissions Example:

  • Employee commuting falls under scope 3.

cep1014-lesson-5-employee-commuting-emissions

 

 

Purchased Electricity Emissions Example:

  • Purchased electricity falls under scope 2

cep1014-lesson-5-purchased-electricity-emissions

 

Stationary Emissions​ Example:

  • Stationary combustion falls under scope 1

cep1014-lesson-5-stationary-emissions

Overall Carbon Footprint

  • All of the calculated emissions in CO2-e/year are added up to calculate the carbon footprint of the organisation for that particular year
  • The overall emissions can be normalised (e.g. kgCO2-e/unit of product produced) in order to compare with a baseline year, if production has changed
  • It is helpful to visualise the split between scope 1, 2 and 3 emissions
  • If one source of emissions is far bigger than the others, create plots excluding it, to see more detail

Conclusion

  • Role of MfE’s emissions guidance document
  • GHG inventories vs. GHG reports
  • How to use emissions factors to calculate emissions
  • How to manipulate raw data to be used alongside emissions factors
  • Emissions calculation examples
  • Overall company carbon footprint

Reference Links 

  1. https://environment.govt.nz/assets/publications/Measuring-Emissions-Guidance_DetailedGuide_2023_ME1764.pdf