Scope 1 Emissions: The Only Scope You Directly Own

Scope 1 emissions are the greenhouse gases released directly from sources a company owns or controls. Fuel burned in your boilers, diesel consumed by your fleet, process gases from your production line, refrigerants leaking from your chillers. If the source sits on your property or under your operational authority, its emissions are Scope 1.

Simple definition, messy reality. Global fossil CO2 hit a record 37.4 GtCO2 in 2024, roughly 0.8% above 2023. Every corporate Scope 1 inventory is a controlled slice of that total. And right now, between IFRS S2 enforcement, ESRS E1 in Europe, and California’s SB253 going live, that slice is no longer optional to quantify. It’s auditable.

This guide covers what counts as Scope 1, what doesn’t, how to measure it, where most inventories go wrong, and what the regulatory landscape actually demands today.

What Falls Under Scope 1 (and What Doesn’t)

The EPA breaks Scope 1 into four source categories: stationary combustion, mobile combustion, process emissions, and fugitive emissions. That taxonomy hasn’t changed in years, but the boundary between “mine” and “not mine” still trips up experienced teams.

Stationary combustion is fuel burned in fixed equipment. Boilers, furnaces, turbines, backup generators. If your facility runs a natural gas boiler for process heat, every cubic meter of gas burned produces Scope 1 CO2.

Mobile combustion is fuel burned in vehicles and equipment the company owns or controls. Company trucks, forklifts, ships, aircraft. Own the fleet, own the emissions. Hire a third-party carrier, and those emissions shift to your Scope 3 (and the carrier’s Scope 1).

Process emissions come from chemical or physical transformations that have nothing to do with burning fuel. Cement plants release CO2 when limestone is calcined. Chemical plants release gases during synthesis. These are baked into the production process itself, which is what makes them so hard to eliminate.

Fugitive emissions are the quiet ones. Refrigerant leaks from HVAC and cold-chain equipment. Methane escaping from valves in oil and gas operations. SF6 leaking from electrical switchgear. They often go unmeasured until someone runs a leak survey and finds a number that dwarfs the entire fleet.

What is NOT Scope 1: electricity you purchase (Scope 2), emissions from your suppliers’ operations (Scope 3), employee commuting (Scope 3), and anything from assets you don’t own or control.

Scope 1 vs. Scope 2 vs. Scope 3 at a Glance

The logic is ownership and control. You burn diesel in your truck: Scope 1. A power plant burns coal to generate the electricity you buy: Scope 2. Your supplier burns fuel manufacturing parts you purchase: Scope 3.

Your degree of direct influence tracks the scope number. Scope 1 is where you hold the wrench. Scope 2 is where you hold the contract. Scope 3 is where you hold influence, sometimes barely. That’s why Scope 1 is the natural starting point for any operational decarbonization effort: the levers are in your hands.

How to Calculate Scope 1 Emissions

The math is not complicated. The data collection is. Here’s the workflow most GHG inventories follow:

1. Set your organizational boundary. Decide whether you’re using equity share, financial control, or operational control. This choice determines which assets appear in your inventory (more on this below).
2. Build a source register. Every boiler, generator, fleet vehicle, refrigeration unit, fire suppression system, and industrial process that releases greenhouse gases directly. If it burns fuel, holds refrigerant, or transforms material, it belongs on the list.
3. Collect activity data. How much fuel did each source consume? How much refrigerant was topped up? What production volumes drove process emissions? Pull from fuel purchase records, maintenance logs, and process control systems.
4. Apply emission factors. The EPA GHG Emission Factors Hub provides transparent default factors for organizational reporting. Match each fuel type and gas to its factor, accounting for CO2, CH4, and N2O where applicable.
5. Convert to CO2 equivalent. The GHG Protocol Corporate Standard covers seven gases: CO2, CH4, N2O, HFCs, PFCs, SF6, and NF3. Multiply each gas by its global warming potential and sum.
6. Document everything. Factor versions, data sources, assumptions, boundary decisions. If your inventory can’t survive a factor revision or a restatement request, it’s not an inventory. It’s a guess wrapped in a spreadsheet.

A note on data quality: default factors are where you start, not where you stay. For your top three sources by volume, upgrade to metered data, continuous monitoring, or supplier-specific factors as soon as practical. For the rest, a credible default with documentation beats an expensive meter nobody maintains.

One thing I see industrial teams miss repeatedly: refrigerants. A company will meticulously track fleet diesel and completely ignore the 200 kg of R-410A topped up across twenty rooftop units last year. At a GWP of 2,088, that’s over 400 tonnes CO2e that never made it into the inventory. That kind of blind spot isn’t rounding error. It’s a material omission.

Organizational Boundaries: Where Most Inventories Break

Two companies can own the same type of facility and report very different Scope 1 numbers. The difference isn’t dishonesty. It’s the consolidation approach.

The GHG Protocol recognizes three approaches:

• Equity share: You report emissions proportional to your ownership stake. Own 40% of a joint venture? Report 40% of its Scope 1.
• Financial control: You report 100% of emissions from entities where you direct financial and operating policies.
• Operational control: You report 100% of emissions from operations you run day-to-day, even if you don’t fully own them.

The choice cascades into everything. A trucking company that leases its fleet under an operational-control approach reports those vehicles in Scope 1. The same company using equity share might not, depending on the lease structure. Joint ventures, franchises, and outsourced operations all shift depending on which method you pick.

This is not academic. When regulators, investors, or customers compare your number to a competitor’s, the comparison is meaningless unless both used the same approach. Always state your method. And if you’re evaluating someone else’s report, check theirs before drawing any conclusions.

Where Scope 1 Regulation Stands Right Now

Disclosure is converging globally, even as individual jurisdictions move at different speeds. Here’s the current map.

IFRS S2 (global, via ISSB): Requires Scope 1, 2, and 3 measurement under the GHG Protocol. Adopted or in process across jurisdictions covering major capital markets. If your investors follow ISSB-aligned standards, Scope 1 disclosure is baseline.

ESRS E1 (Europe): Requires absolute gross Scope 1, 2, and 3 emissions in metric tons CO2e. The word “gross” matters. You cannot net offsets against your Scope 1 total and call it done under this standard.

California SB253 (US): Applies to entities with over $1 billion in annual revenue doing business in California. CARB’s current plan places Scope 1 and 2 in the initial reporting cycle, with Scope 3 beginning in 2027. The proposed first-year deadline of November 10, 2026 remains subject to the rulemaking process.

US SEC: Proposed rescinding its climate-related disclosure rules on May 29, 2026, with a 60-day public comment period. That proposal is not a completed repeal. Companies with global operations, California exposure, or ISSB-aligned investors still need Scope 1 data regardless of what happens at the federal level.

GHG Protocol update: The Protocol’s Request for Information remains open until February 1, 2027, with a formal draft-standard consultation planned for Q3 2027. If you’re building an inventory now, preserve raw activity data and factor provenance. A revised standard may require retrospective adjustments.

The practical takeaway: even in a fragmented regulatory environment, building a credible Scope 1 inventory is operational infrastructure, not a compliance checkbox. It also feeds the sustainability metrics, the broader environmental impact assessment, and the ESG compliance reporting that guide real decisions. The companies with clean data now won’t be scrambling when the next deadline lands.

Real Companies, Real Numbers

Here’s what Scope 1 actually looks like in corporate reporting, including the parts companies would prefer you didn’t scrutinize.

Microsoft cut combined Scope 1 and 2 emissions 29.9% from its 2020 baseline in FY24. Impressive. But total emissions rose 23.4% above that same base year because Scope 3 surged 26%, driven by data-center construction and supply-chain growth. A strong Scope 1 and 2 result can coexist with a growing total footprint. Judge the full boundary, not the headline.

Genco Shipping reported company-owned-vessel Scope 1 emissions of 901,575 tCO2e in 2022, rising to 931,917 in 2023, then falling to 861,255 in 2024. A 3.4% increase followed by a 7.6% decrease. The fluctuation reflects fleet composition, voyage activity, weather, and fuel mix. Genco invested $632M since 2018 in fleet modernization, Mewis ducts, propeller upgrades, and voyage optimization. Annual numbers move. The trajectory, and the engineering behind it, matters more than any single year.

Heidelberg Materials illustrates why cement is the hardest Scope 1 sector. Calcination (heating limestone) releases CO2 regardless of fuel choice. The company has a validated target to reduce gross Scope 1 and 2 by 26.7% per tonne of cementitious material by 2030. Note: that’s a validated target, not evidence the reduction has already occurred. Fuel switching addresses combustion, but clinker substitution and carbon capture are the only realistic paths for process emissions.

Apple reported supplier F-GHG abatement of 8.4 million tCO2e in fiscal 2024. That’s supplier engagement, not Apple’s own Scope 1 total. The distinction matters: when a company reports abatement through its supply chain, the words “supplier,” “avoided,” and “abated” must remain attached to the figure. Strip those qualifiers and the number becomes misleading. Credible supply chain sustainability claims depend on keeping those distinctions intact.

How to Reduce Scope 1 Emissions

Reduction starts with knowing which sources are material. In most industrial operations, 80% of Scope 1 comes from two or three source types. Find those first. Then act in order of cost-effectiveness.

Fuel switching and electrification. Replace natural gas boilers with heat pumps where heat profiles allow. Transition fleet vehicles from diesel to electric or renewable fuels. Swap backup diesel generators for battery storage where duty cycles support it. Each substitution has a payback calculation. Run it before running the press release.

Operational efficiency. Better equipment doesn’t help if it runs wastefully. Voyage optimization in shipping, load consolidation in trucking, building management systems in facilities. These are fuel-demand reductions that cut Scope 1 and operating cost simultaneously. The data usually exists inside operational systems already. It’s just not connected to the emissions inventory.

Methane and fugitive control. IEA estimates about 35 Mt of energy-sector methane could be avoided at no net cost under average 2024 energy prices. For oil and gas, leak detection and repair programs pay for themselves by capturing saleable gas. For any company running refrigeration at scale, systematic leak management can eliminate hundreds of tonnes CO2e per year. OGMP 2.0 is pushing measurement-based methane reporting toward covering nearly a third of global oil and gas supply by 2030.

Process redesign. Where emissions come from chemical or physical transformations, reduction means changing the process. In cement: alternative binders, clinker substitution, carbon capture. In chemicals: catalytic improvements, feedstock changes. These are capital-intensive, multi-year decisions, but they’re the only way to address process Scope 1 at the root.

A note on offsets: purchasing carbon credits does not reduce your gross Scope 1. The GHG Protocol separates corporate inventory accounting from project-based mitigation. You can disclose offsets alongside your inventory, but the gross number stays gross. If your carbon reduction strategy depends on offsets instead of source-level engineering, that will surface in any serious audit.

The Gap Between Asset Data and Emissions Data

One pattern I see consistently across logistics, aviation, and maritime operations: the team responsible for Scope 1 reporting and the team managing physical assets rarely share a system. Fleet managers track GPS and fuel using industrial GPS tracking devices, facility managers handle maintenance tickets, and the sustainability team gets a spreadsheet stitched together from email chains, weeks after the reporting period closes.

That disconnect is where inventory errors live. Missing vehicles. Untracked equipment. Refrigerant top-ups buried in work orders nobody aggregates.

When assets carry IoT trackers, the operational data feeding Scope 1 calculations (fuel consumption, runtime hours, location-based activity) becomes continuous instead of quarterly. Trackers don’t replace emission factors or boundary decisions, but they solve the activity-data problem at the source. Wireless environmental monitoring systems enable real-time visibility across distributed operations, turning what was once quarterly manual data pulls into continuous feeds that support both operational decisions and emissions reporting. If your fleet, containers, or ground support equipment operate across multiple sites and your Scope 1 inventory still depends on manual data pulls, that gap is worth closing.

We help industrial and logistics teams connect operational asset visibility to the data their sustainability programs need. If that sounds like your situation, reach out to our team or browse our asset tracking solutions.

Frequently Asked Questions

What are Scope 1 emissions?

Scope 1 emissions are direct greenhouse gas releases from sources a company owns or controls: fuel combustion in boilers and vehicles, process emissions from industrial operations, and fugitive releases like refrigerant leaks and methane venting. They are distinct from Scope 2 (purchased energy) and Scope 3 (value chain) emissions.

What is an example of a Scope 1 emission?

A company truck burning diesel is Scope 1. The CO2, CH4, and N2O from that combustion are direct emissions under the company’s control. Other examples: natural gas in a factory boiler, methane from a pipeline valve, refrigerant escaping a warehouse cooling system, and CO2 released during cement calcination.

Is purchased electricity Scope 1 or Scope 2?

Purchased electricity is Scope 2. The power plant that generates it reports those combustion emissions as its own Scope 1. However, if you generate electricity on-site by burning fuel in your own generator, that combustion is your Scope 1.

Do leased vehicles or facilities count as Scope 1?

It depends on your consolidation approach. Under operational control, assets you operate are included in your Scope 1 even if you don’t own them. Under equity share, only your ownership portion counts. The GHG Protocol requires companies to state their approach and apply it consistently across all assets.

Can carbon offsets lower my Scope 1 total?

No. Offsets can be disclosed alongside your inventory as part of a net target, but they do not change the gross Scope 1 figure. The GHG Protocol treats corporate inventory accounting and project-based mitigation as separate instruments. Regulators like ESRS E1 explicitly require gross emissions disclosure.

How often should a company report Scope 1 emissions?

Most frameworks (IFRS S2, ESRS E1, California SB253) require annual disclosure aligned with financial reporting cycles. For operational decision-making, however, quarterly or continuous monitoring of material sources delivers faster insight into where reductions are actually happening.