Decarbonization: what it is and why it matters
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What is decarbonization, and why is it urgent? Learn practical steps companies can take to support the global move toward net zero emissions.
What Are Scope 1 Emissions?
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By Stephanie Safdie, US Copywriter, on 08/26/2026
Updated by Agnès Potier-Murphy
Scope 1 sits at the top of every corporate carbon footprint: it's the emissions a company creates itself, not the ones baked into what it buys or the electricity it plugs into. If your business burns fuel — in a vehicle, a boiler, a generator — that's Scope 1.
With California's SB 253 now requiring large companies to disclose Scope 1 and Scope 2 emissions — the first reporting cycle is expected by November 2026 — more US businesses have a direct, concrete reason to understand exactly where their Scope 1 emissions come from.
The GHG Protocol, which is the standard virtually every company uses for this, splits carbon accounting into three categories, or "scopes." Scope 1 is the first.
This guide covers what actually counts as a Scope 1 emission, how to calculate one, how Scope 1 stacks up against Scope 2 and Scope 3, and where US companies can realistically start cutting their Scope 1 greenhouse gas emissions.
Key Topics You’ll Learn About in This Article
What Are Scope 1 Emissions? (with real examples)
How to Calculate Scope 1 Emissions
Scope 1 vs. Scope 2 vs. Scope 3 Emissions
How to Reduce Scope 1 Emissions
What Are Scope 1 Emissions?
What Is the Definition of Scope 1 Emissions?
Scope 1 emissions are the first category in carbon accounting: direct greenhouse gas emissions from sources a company owns or controls. This includes fuel burned in company vehicles and on-site equipment such as boilers, furnaces, and heavy machinery. Purchased electricity, heat, steam, or cooling — even for facilities the company owns or leases — falls under Scope 2, since those emissions physically occur at the utility or generator, not on-site.
Ford Motor Company offers a useful real-world benchmark: it has an SBTi-approved target to cut combined Scope 1 and Scope 2 emissions from its global operations 76% by 2035 against a 2017 baseline, and its most recent sustainability disclosure reports a 49% reduction already achieved by the end of 2024, largely through facility efficiency upgrades and expanded renewable electricity procurement at its plants.
What Are Some Examples of Scope 1 Emissions?
The vertical timeline below will reveal how scope 1 emissions are created. Under the GHG Protocol, these fall into four official categories: stationary combustion, mobile combustion, fugitive emissions, and process emissions. Here's what each one actually looks like:
1. Stationary Combustion 🔥
Fuel burned in company-owned boilers, furnaces, ovens, heaters, and turbines at facilities (e.g., natural gas, diesel, fuel oil) releases direct CO₂, CH₄, and N₂O.
2. Mobile Combustion 🚚✈️
Gasoline, diesel, CNG, or LPG used in company vehicles, forklifts, ships, or aircraft produces tailpipe emissions owned or controlled by the company.
3. Fugitive Emissions 🧊💨
Leaks and servicing losses from HVAC, refrigeration, heat pumps, or fire-suppression systems release high-GWP gases (e.g., HFCs) directly into the atmosphere.
4. Process Emissions 🧪
Industrial processes account for a real share of this category: cement clinker and lime calcination, metal smelting, and hydrogen or ammonia production are all chemical reactions inside owned equipment that release CO₂ and other gases directly.
5. On-Site Power Generation ⚡️
Fuel used in on-site generators, microturbines, or combined heat & power (CHP) units to make electricity/steam for operations creates direct GHG emissions.
6. Emergency & Backup Equipment 🆘
Standby generators, compressors, and safety-relief vents that combust fuel during tests or outages contribute to Scope 1 when owned or controlled by the company.
7. Other Direct On-Site Sources 🏭
Emissions from company-owned waste incineration or flaring, and methane from on-site wastewater or landfills operated by the company, are also Scope 1.
How Do You Calculate Scope 1 Emissions?
At its core, every Scope 1 calculation is the same multiplication: activity data × emission factor.
Take a company heating its facility with natural gas. US gas bills are typically metered in therms rather than kilowatt-hours — say a facility uses 5,000 therms (500 MMBtu) over the year. Multiply that by EPA's published emission factors for natural gas combustion, applied separately to each gas involved:
500 MMBtu × 53.06 kg CO2/MMBtu = 26,530 kg CO2
500 MMBtu × 1.0 g CH4/MMBtu = 0.5 kg CH4 → × 28 (100-year GWP) = 14 kg CO2e
500 MMBtu × 0.10 g N2O/MMBtu = 0.05 kg N2O → × 265 (100-year GWP) = 13.25 kg CO2e
Total: 26,530 + 14 + 13.25 = 26,557.25 kg CO2e, or about 26.6 metric tons CO2e
That's the facility's Scope 1 stationary combustion emissions from natural gas for the year. The same multiplication applies to every other Scope 1 source too — fuel used in company vehicles, refrigerant top-ups, on-site process emissions — only the activity data and the emission factor change.
Emission factors aren't static either: EPA typically refreshes the Hub once a year, usually in the first quarter, most recently updating global warming potentials to align with the IPCC's newest assessment. Always confirm you're working from the current edition before finalizing a report.
Quick Reminder: What Is Carbon Accounting?
Carbon accounting is how companies trace their emissions back to the source, sorting them into categories, or "scopes," as defined by the GHG Protocol.
These scopes aim to break down the sources of activity which produce carbon dioxide emissions, so that a company can better understand their carbon footprint.
Carbon accounting is also referred to as greenhouse gas accounting.
Carbon accounting has been gaining recognition, as it often serves as the first step when companies decide they are ready to comprehend their own carbon footprint – and allows them to determine the next steps necessary to reduce their own carbon emissions.
Why Are Scope 1 Emissions Important?
Scope 1 emissions matter because they're the category a company has the most direct influence over, though "direct influence" isn't the same as complete control: leased sites, joint ventures, and franchise arrangements all complicate who's actually accountable for a given emission source.
The interactive flip cards below (move cursor over card to flip) will reveal some of the main reasons why scope 1 emissions are important:
🔥 Direct Emission Awareness
Scope 1 emissions highlight the greenhouse gases produced directly from company-owned sources, such as vehicles and facilities — giving organizations a clear view of their operational footprint.
⚙️ Operational Accountability
Tracking Scope 1 emissions holds businesses accountable for their direct energy use and encourages the transition to cleaner fuels and efficient systems.
🌍 Supports Net-Zero Strategies
Understanding Scope 1 emissions is the foundation for building effective reduction plans and achieving long-term carbon neutrality goals.
📊 Improves Transparency & Reporting
Disclosing Scope 1 data enhances ESG reporting accuracy and demonstrates corporate responsibility to investors, regulators, and stakeholders.
Reducing Scope 1 emissions doesn't automatically reduce Scope 2 emissions — in fact, the opposite is often true. Switching a Scope 1 source to electricity (replacing a gas boiler with an electric one, for example) shifts those emissions into Scope 2 rather than eliminating them. That's a deliberate feature of the GHG Protocol, designed to prevent the same emissions being counted twice across a company's own scopes.
Scope 1 vs. Scope 2 vs. Scope 3: What's the Real Difference?
As a whole, scope 1 emissions (like any emissions created by a company) play a role on the company's carbon footprint – but scope 1 emissions are generally easier to measure and manage, especially in comparison to scope 3 emissions (which are notoriously difficult to effectively define and reduce).
This ties back to the boundary-shift point above: cutting Scope 1 doesn't shrink Scope 2, and can sometimes push it higher. But Scope 2 has its own separate levers — a renewable electricity contract, more efficient equipment on the purchased-energy side — that work independently of whatever's happening in Scope 1.
How do Scope 1 Emissions Differ From Scope 2 and Scope 3 Emissions?
Companies typically tackle Scope 1 and Scope 2 together first, since both are more straightforward to measure and report — increasingly under mandatory frameworks like SB 253 — while Scope 3 gets assessed separately given how much more complex it is to pin down.
The battle cards below will reveal the differences between scope 1, scope 2, and scope 3 emissions:
🏭 Scope 1 Emissions
🔥 Direct emissions from owned or controlled sources
🚚 Includes emissions from fuel combustion in company vehicles and facilities
🏢 Typically easiest to measure and directly manage
⚙️ Required for disclosure under SB 253 and most reporting frameworks
💡 Scope 2 Emissions
⚡ Indirect emissions from purchased energy (electricity, heating, cooling, steam)
🏠 Occurs at the utility provider but tied to organizational energy use
📈 Can be reduced through energy efficiency and renewable sourcing
📊 Essential for tracking total corporate carbon footprint
🌍 Scope 3 Emissions
🚢 Indirect emissions from the value chain (upstream & downstream)
📦 Includes business travel, purchased goods, waste, transportation, and use of sold products
🧮 Most complex to calculate, but often largest share of total emissions
🔍 Critical for companies aiming for net-zero or full ESG transparency
How Can You Reduce Scope 1 Emissions?
Cutting Scope 1 emissions really comes down to three things: burning less, burning cleaner, or burning more efficiently. Some of that is a quick operational fix; some requires real capital investment. Here are three levers worth working through, roughly in order of how fast they pay off:
Improve On-Site Fuel and Heating Efficiency
Efficiency is the fastest lever most companies have if they burn fuel on-site, for space heating, hot water, or manufacturing processes. Simple habits like shutting down boilers and furnaces during off-hours, keeping equipment properly maintained so it burns cleanly, and replacing aging units with higher-efficiency models can all cut Scope 1 emissions meaningfully without a major capital investment.
Swapping a gas furnace for an electric heat pump goes further still, though it’s worth remembering that it shifts the emissions into Scope 2 rather than erasing them, so it's most effective paired with a renewable electricity contract.
Manage Refrigerant Leaks and Fugitive Emissions
Refrigerant leaks are one of the most commonly overlooked sources of Scope 1 emissions: they show up in air conditioning, refrigeration units, and fire-suppression systems most companies barely think about. Routine leak checks and proper equipment maintenance catch losses early, and choosing lower-GWP refrigerants whenever equipment is replaced reduces the impact of any leaks that do happen — all without touching your core operations.
Switch Your Fleet to Electric Vehicles
Switching company vehicles to electric is one of the most direct ways to cut Scope 1 mobile combustion emissions outright, and total running costs typically come in lower than gasoline or diesel over a vehicle's lifetime.
The federal purchase credit that used to sweeten this decision ended for vehicles acquired after September 30, 2025, but several states still run their own incentive programs. California's DriveClean initiative, for instance, lists current rebates, HOV lane access, and other perks for going electric. As with heating and refrigeration, remember that electrifying a fleet shifts emissions into Scope 2 rather than eliminating them, so pairing it with a renewable electricity contract is what actually gets you the full reduction.
Frequently Asked Questions about Scope 1 Emissions
What exactly counts as a Scope 1 emission?
Anything your company directly burns or leaks counts: fuel in boilers, furnaces, or on-site generators (stationary combustion), fuel in company vehicles (mobile combustion), refrigerant or gas leaks (fugitive emissions), and emissions from on-site chemical or industrial processes (process emissions). Electricity, heat, or steam you buy from someone else doesn't count here — that's Scope 2, not Scope 1.
What's the difference between Scope 1 and Scope 2 emissions?
Scope 1 covers direct emissions from sources you own or control — company vehicles, on-site boilers, that kind of thing. Scope 2 covers the electricity, heat, or steam you purchase to run those same operations. Under California's SB 253, large companies doing business in the state have to disclose both together, and most other US disclosure frameworks follow the same pairing.
Do refrigerant leaks count toward Scope 1?
Yes, refrigerant leaks from equipment you own or control, like air conditioning or refrigeration units, are classified as fugitive emissions under Scope 1, right alongside things like methane leaks from gas equipment. Any unintentional release from equipment you control falls into this category.
Does switching to electric vehicles lower my Scope 1 emissions?
Yes, directly — no more fuel burned means no more Scope 1 emissions from that vehicle. But those emissions don't vanish: they move into Scope 2, since the vehicle now runs on purchased electricity instead. The GHG Protocol treats this as a boundary shift, not a net reduction, so it's worth tracking Scope 1 and Scope 2 together rather than counting it as a win on its own.
Is Scope 1 reporting mandatory in the US?
It depends on the company. There's no single federal mandate — the SEC's climate disclosure rule was never enforced and is now being formally rescinded — but California's SB 253 requires companies with over $1 billion in global revenue doing business in the state to disclose Scope 1 and Scope 2 emissions, with the first reports due in the second half of 2026. Scope 3 disclosure follows in 2027.
How do you actually measure Scope 1 emissions?
You track activity data for everything your company burns or leaks — fuel receipts, meter readings, refrigerant top-up records — then apply the matching emission factor for each source. Most companies pull this together using utility bills, fleet fuel logs, and equipment maintenance records rather than direct measurement equipment, since EPA's published factors make the calculation reliable without needing to instrument every source.
What About Greenly?
If reading this article about scope 1 emissions has made you interested in reducing your carbon emissions to further fight against climate change – Greenly can help you!
Greenly can help you make an environmental change for the better, starting with a carbon footprint assessment to know how much carbon emissions your company produces.
Click here to learn more about Greenly and how we can help you reduce your carbon footprint.
California Air Resources Board (CARB), CARB Approves Climate Transparency Regulation for Entities Doing Business in California
GHG Protocol, A Corporate Accounting and Reporting Standard (Revised Edition)
Ford Motor Company, 2025 Integrated Sustainability and Financial Report
EPA, GHG Emission Factors Hub
Greenly, What Is the Greenhouse Gas Protocol?
Greenly, What Are Scope 3 Emissions?
Greenly, What are Scopes 1, 2 and 3 Emissions?
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