👋 Hey, this is a newsletter where every Tuesday and Friday you get something about product management, tech, or sustainability, and how they fit together. In between, you’ll get stories I think you’ll like. If that sounds interesting, sign up😊.

Greenhouse gas (GHG) accounting is an important function of the sustainability industry that, conceptually, is a lot easier than it sounds. It’s the process of accounting for the amount of greenhouse gas emissions produced by a given person or organisation. In essence, working out a carbon footprint. 

It has a big fancy name because of the scale of the calculations. To do it properly you have to take into account the subject’s ‘activity data’, calculate the emissions for each one using ‘emission factors’, and break that information down into the primary gases that are emitted. Doing this for even a small organisation can mean hundreds, if not thousands of calculations.

Activity data

In GHG accounting ‘activity data’ refers to the data that describes what is being done to emit emissions. For a single household this means everything from the electricity you use to charge your devices, to the planes you use to take a holiday and everything in between. And believe me, there’s a lot in-between. 

For companies it means everything from the energy they take from the grid to create their products, to the energy their employees use while working from home, heck, just having money in the bank fuels emissions. It all gets split up into different categories to be properly understood, categorised, and accounted for. 

Emission Factors

Once the data is collected and organised nicely it is converted into emissions. This is done by multiplying the ‘amount’ of a given activity being done by the mass of greenhouse gases it produces. The factor that the activity is multiplied by is called the ‘emission factor’ and is derived from the energy the activity in question uses. 

These factors differ based on where you are in the world and the exact kind of activity you’re doing but are well understood. There are global databases of these factors that cover everything from jet fuel to ice cream that are publicly available. Armed with this information you can break emissions down into their primary gasses and their ‘global warming potential’ (GWP).

• Carbon dioxide (CO2) (GWP = 1)
• Methane (CH4) (GWP = 21)
• Nitrous oxide (N2O)         (GWP = 310)
• Sulfur Hexafluoride  (SF6) (GWP = 23,900)
• Hydrofluorocarbons (HFCs) (GWP = 12 – 12,000)
• Perfluorocarbons (PFCs) (GWP = various)

GWP is the emissions converted to CO2-equivalents, the standard unit for measuring emissions. 

Why do GHG accounting

The goal is to calculate and organise emission data using common standards and protocols in order to attribute emissions to some entity so that they can track their emissions over time. They can then:

• Achieve corporate social responsibility goals
• Identify how to best reduce their emissions
• Reduce costs associated with emissions
• Gain a competitive advantage (dangerous but powerful motivation)
• Participate in GHG reporting programs
• To prepare for GHG policies of the future

South Pole, the company I work for and a leading sustainability consultancy push for ‘The Climate Journey’. 5 steps for organisations to take in order to reduce their emissions in line with scientific predictions of climate change. The first step is calculation, which for companies means, GHG accounting. They say that the first step to reducing your emissions is to understand your emissions. Simply talking about the emissions you have isn’t enough, you need to walk the talk too.

This is a concept that can be applied to individuals too. If you know your emissions, account for them, then you can make real, impactful changes, to reduce them. As long as you are able and stay away from ‘climate guilt’.

Thanks for reading. The best way to support this newsletter is to sign up if you haven’t already, share it around, and get your friends to sign up too. That’s what this lovely purple button is for …