News and insights: Rejoose on Carbon Data & Sustainable IT 

What are Carbon Accounting Methods and should commercial teams care?

Skrevet af Thomas Mardahl | Jul 8, 2025 9:07:11 AM

This is Part One of the Rejoose Sustainability Knowledge Partner Series. 

 
Let’s face it carbon reporting often sounds like something for ESG people, not commercial teams trying to hit targets, win business, and deliver value.

But here's the reality: Carbon reporting data is fast becoming part of every deal, every quote, and every customer conversation.

If you work in sales, procurement, product, or channel partnerships, you willbe asked about emissions sooner than you think, if not already.

So, we are launching this short series to make carbon clarity part of your commercial toolkit: Simple, honest insights, no greenwashing and no jargon.

Let’s start with a foundational question: How is carbon actually calculated in business today?

We can calculate in four ways: 

Spend-Based Method
Average-Data Method 
Hybrid Method
Manufacturer-Specific Method 

According to the GHG Protocol (the global standard for carbon reporting), there are four recognised ways to calculate emissions from purchased goods: like laptops, servers, phones, cables etc.

These four methods are often seen as an evolution ladder: The higher you go, the better your accuracy, and your credibility.

Let’s break them down, commercial style. 

 

Tier 1: Spend-Based Method

Carbon calculated from price tags.

This is the easiest, and the weakest method. You take how much you spent on a product and multiply it by a standard emissions factor.

◊ It is super quick
◊ Wildly inaccurate
◊ Often used in early-stage reporting to show something on paper

Why it’s risky: Two laptops costing €1,000 can have totally different carbon footprints. One might use 130 kg CO₂e, the other 400 kg. Spend-based doesn't know the difference.

 

Tier 2: Average-Data Method

Carbon based on the type of product you bought.

Now we are getting smarter. This uses real lifecycle data, like average emissions for “14” business laptops” or “2U rack servers.” Still a bit general, but way more product-aware.

◊ Up to 90% more accurate than spend-based
◊ Still based on assumptions and averages
◊ A great step for companies starting to take reporting seriously

 

Tier 3: Hybrid Method

Mix of average data + some tier 4 real product data.

This is the sweet spot for many businesses right now. You use verified carbon data where you have it (e.g. top-selling products), and trusted averages for the rest.

◊ High accuracy, scalable across your whole catalogue
◊ Needs a bit of infrastructure or partner help
◊ This is where smart suppliers can really help their customers climb the ladder

 

Tier 4: Manufacturer-Specific Method (The best method)

Exact data from the manufacturer for the specific product.

This is what the GHG Protocol calls “supplier-specific”. We will call it manufacturer-specific, because that’s what it is in practice. This is the gold standard: Accurate, auditable, and future-proof.

But in the IT industry, only around 15% of products currently have this level of data available. That number will grow, but until then, we need smart ways to bridge the gap.

◊ The best method
◊ Coverage is still limited
◊ Expected to become mainstream within 3–5 years

 

Why You’ll Need to Combine Methods (and why it is fine) 

Let’s be real: no company, not even the most advanced, can use one single carbon accounting method across their entire product portfolio.

Especially in IT, where a typical company might purchase hundreds or thousands of unique products each year, you will need to combine multiple methods to get full coverage.

To build a credible and complete carbon picture, you don’t pick just one method, you combine them:

  1. Manufacturer-Specific: Use for high-volume or strategic products where verified data is available
  2. Hybrid Method: Use to blend product-level and category-level data for improved coverage and practicality
  3. Average-Data Method: Use to cover remaining products where no better data exists (yet)

By combining these three activity-based methods, companies can:

◊ Replace spend-based guesswork

◊ Improve accuracy across their entire portfolio

◊ Show clear progress toward more trustworthy carbon reporting

This layered approach is exactly how the best companies climb the ladder.

 

Why this matters to commercial teams

Most of your customers are still on Tier 1 or 2, and looking for help to improve. If you can support them with Tier 3 data, you suddenly go from "just another supplier" to a valuable partner in their sustainability journey.

You’re not selling them lower-carbon products. You’re helping them prove it, and that is what counts in public tenders, large framework deals, and strategic accounts.

 

What you can do today

If you are in sales, product, procurement or channel:

◊ Start asking how your company handles carbon data today
◊ Understand where your customers are on the ladder
◊ Offer carbon data beyond spend-based where you can
◊ Partner with platforms or tools that deliver hybrid or manufacturer data automatically
◊ Use this data to position your business as solution-oriented and sustainability-smart

 

Part of the Rejoose Sustainability Knowledge Partner Programme

This post is the first in a short series to help commercial leaders get confident in carbon data, and use it to build stronger, smarter customer relationships.

Next up is “How to Use Carbon Data in Your Sales Conversation Without Greenwashing”

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