Where Carbon Data Comes From

Welcome to Teaching Sustainability, the 20-week series from Aclymate created to help small and mid-sized business leaders understand what sustainability means, why it matters, and what to do next. Each week, we cover one practical topic — from carbon accounting and reporting to certifications and climate action — in clear, simple language designed to help you build a more resilient, credible, and competitive business.

We've now covered the why and the what of carbon accounting — why it matters, what CO₂e means, and how the GHG Protocol organizes emissions into three scopes. But there's a question that tends to come up at this point that's more practical than conceptual: where does the actual data come from?

The answer is more familiar than most people expect. The raw material for a carbon inventory isn't exotic scientific data. It's the operational information your business already generates — utility bills, fuel receipts, expense reports, shipping records, procurement data. Carbon accounting is largely the process of taking business-as-usual records and running them through a standardized calculation. The data is already there. The work is knowing what to collect and how to use it.

The Basic Equation

Every emissions calculation follows the same logic: activity data multiplied by an emission factor equals greenhouse gas emissions. Activity data is the physical quantity of something your business does or consumes — gallons of fuel, kilowatt-hours of electricity, miles traveled, dollars spent. The emission factor is a standardized conversion rate that translates that activity into CO₂e. Multiply the two, and you have your emissions figure.

You don't need to derive these factors yourself. They're published by authoritative bodies — the EPA, the International Energy Agency, the UK government — and are updated regularly. The work of carbon accounting is gathering the activity data. The conversion is handled by existing, well-established tables.

Energy: Your Utility Bills Are the Starting Point

For most businesses, energy is where the data collection begins. Electricity usage, measured in kilowatt-hours, comes directly from your utility bills. Natural gas consumption, in therms or cubic feet, comes from your gas invoices. If your facilities use fuel oil, propane, or steam, those records come from supplier invoices or on-site meters.

One important nuance with electricity: the same kilowatt-hour can have a very different emissions impact depending on where and when you use it. Power generated from coal carries a much higher emission factor than power from hydroelectric or wind. This is why location and grid composition matter in carbon accounting — and why some organizations pursue renewable energy certificates to reduce the emissions intensity of their purchased power. More on that when we cover Scope 2 in depth next chapter.

Fuel: What Goes Into Your Vehicles and Equipment

If your company owns or operates vehicles — delivery vans, trucks, company cars, forklifts, generators — the fuel those vehicles consume is part of your emissions inventory. Gasoline and diesel purchase records, fleet management logs, and fuel card data are all viable sources. For larger fleets, telematics systems often track fuel consumption automatically.

The same applies to stationary equipment: boilers, furnaces, backup generators. Natural gas usage for heating shows up on utility bills; diesel for a backup generator comes from fuel delivery records or tank level tracking.

One category worth flagging that often gets overlooked: refrigerant leaks from HVAC and cooling systems. These are recorded differently — typically through maintenance logs that track how much refrigerant was added to a system during servicing, which implies how much leaked out. Some refrigerants carry extremely high global warming potentials, so even small amounts can be significant in CO₂e terms.

Travel: Expense Reports and Booking Systems

Business travel is another major data source. For flights, the primary input is miles or kilometers traveled, typically extracted from travel booking systems, expense management platforms, or corporate card data. The same applies to hotel stays, which carry an associated energy footprint. For rental cars, the fuel type and distance driven are what matter.

Employee commuting and remote work energy use fall into a different category — Scope 3 — and are typically estimated using employee surveys or average figures rather than precise individual tracking. The goal is a reasonable estimate, not perfect precision.

Purchasing and Shipping: The Harder Data

Beyond energy and travel, a significant portion of a company's emissions footprint comes from what it buys and how goods move. This is where data collection gets more challenging — and where the spend-based estimation method often comes in.

For shipping and logistics, the key inputs are weight, distance, and mode of transport. Air freight is far more emissions-intensive than ocean shipping; road freight sits somewhere in between. Freight providers and logistics platforms increasingly offer carbon data as part of their reporting, making this easier to capture than it once was.

For purchased goods and services — raw materials, equipment, software, office supplies — precise supplier-level data is the gold standard but rarely available at the start. The practical alternative is to use spend data: how much your company spent in a given category, multiplied by an emissions intensity factor for that category. It's less precise than activity-based data, but it produces a credible estimate that can be refined over time as supplier data becomes available.

What to Do This Week

• Pull together your utility bills for the past 12 months. Electricity and natural gas are your starting point. If you don't have them in one place, now is the time to build that habit. Most utilities offer digital access to 12 to 24 months of historical data.
• Check your maintenance logs for refrigerant top-offs. If your HVAC or refrigeration provider has serviced your equipment recently, ask whether refrigerant was added — and how much. That number is easy to miss and often significant.
• Identify your biggest spend categories for goods and services. You may not have supplier-level emissions data yet, and that's fine. Knowing where you spend the most money is the first step toward knowing where your Scope 3 emissions are likely concentrated.

How Aclymate Helps

Aclymate connects directly to the data sources that matter most — utility providers, accounting platforms, payroll systems — so that activity data flows in automatically rather than requiring manual entry. The platform applies current EPA and IEA emission factors behind the scenes, converting your operational records into a complete CO₂e inventory organized by scope. On the Aclymate One tier, your Carbon Bookkeeper reviews the incoming data, flags gaps, and helps you build the collection processes that make each subsequent year's inventory faster and more accurate than the last.

The Takeaway

Carbon data isn't mysterious. It lives in the same systems your operations team already uses — billing platforms, expense tools, logistics records, maintenance logs. The gap isn't data availability; it's knowing which records to pull, what to do with them, and how to fill in the blanks where precise figures aren't available.

The GHG Protocol is explicit: well-documented estimates are acceptable. Coverage matters more than perfection, especially in year one. Start with what you have, note your assumptions, and improve from there.

Next chapter, we'll get specific about where the majority of those emissions are likely sitting — starting with Scope 2 and the surprising complexity of purchased electricity.