California Climate Accountability Package: SB253, SB261, & SB252
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What is the California Climate Accountability Package, and how do SB 253 and SB 261 (SB 219), and SB 252 help the state work towards their environmental goals?
ESG / CSR
Industries
MEASURE
ACT
COMFORM
What is an Emission Factor?
Level
Key Topics You’ll Learn About in This Article
What emission factors are and how they work
The ups and downs of using emission factors
How to properly calculate emission factors
Between seeking to reduce your carbon emissions, engage with your suppliers, and keep track of your finances – today’s economy and changing market requires companies to exhibit greater efforts towards sustainability, including calculating various components such as an emission factor.
An emission factor refers to the numerical value which is bound to represent the amount of a predetermined pollutant or a greenhouse gas in the atmosphere in relation to the activity in which it was created by.
Why is it imperative for your company to have a good grasp on the importance of an emission factor?
In this article, we’ll explain what an emission factor is, some examples of an emission factor, why they are important, and how your company can calculate an emission factor.
What Is an Emission Factor in Terms of Carbon Dioxide and GHG?
An emission factor is the numerical representation of how much carbon dioxide, methane, or greenhouse gasses are emitted into the atmosphere due to a specific activity.
As a result, an emission factor has been used as a way to help people more easily understand the environmental impact and activity or product created on the planet – such as with round trip plane rides or the average carbon footprint of a holiday dinner.
“Emission factors are per unit of heat content using higher heating values (HHV). If heat content is available from the fuel supplier, it is preferable to use that value. If not, default heat contents are provided. – (EPA).”
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How is an Emission Factor Expressed and Used?
Emission factors are usually expressed in kilograms, metric tons, or pounds per unit of energy, activity or material used.
An emission factor is used for multi-various reasons, such as for the following:
- Environmental Impact Assessment – Often referred to as an EIA, emissions factors can help both researchers and regulators to better understand the environmental impact of various activities, industries, and even how climate change may affect air quality and overall public health.
- Regulatory Compliance – New environmental regulations are being drafted, with some big name regulations such as the CSRD and the SEC Climate Disclosure Rule coming into play – but these massive environmental disclosures would have a tough time setting requirements without emission factors. This is because an emission factor is used to create limits on emissions being produced and aids in the development of reduction strategies.
- Climate Change Reports – Reputable sources such as the IPCC or international agreements like the Paris Climate Agreement will often use emission factors in order to provide a standardized set of information that everyone around the world can understand.
- Sharing Calculations in Carbon Footprint – Emission factors are a great standardized tool and numerical value that everyone can easily understand regardless of language. Therefore, many companies will make use of emission factors to calculate and share their carbon footprints – as well as to track their progress towards emission reductions.
It is important to remember that emission factors may vary depending on various circumstances, such as the technology used to calculate emission factors, business operations, and geographic location – which makes it important to ensure all calculations on emission factors are as accurate as possible to ensure fair creation of environmental policies.
Why Is an Emission Factor Important?
An emission factor is vital to society, especially in the midst of climate change, as it can help provide necessary insight to help in sustainable development, ethical business practices, and even help to develop new climate or environmental policy.
Think of when shopping for the best deal on a new product. This usually means searching for the best quality without needing to spend too much money. The only reason money is involved in the decision is because society has given the product a numerical value. The same goes for emissions created, seeing as an emission factor has provided society with a quantifiable target to create and work towards goals against.
Here are some more reasons as to why emission factors are important:
🧾
Regulatory Compliance
Emission factors already helped to develop new environmental regulations, but how can others make sure that those required to oblige to the regulations are actually meeting the demands? This is done with emission factors, as they serve as a tool to help calculate and share the emissions data of a company or organization.
🌫️
Improve Air Quality
The AQI (AQI) cannot find ways to improve without a baseline of information. This is precisely where emission factors come in, as they are necessary in order to fully understand and measure the impact that industry activities and every day transportation has on our air quality. Without emission factors, it would be more difficult to set concrete targets to improve the Air Quality Index.
📈
Set Concrete Goals
Think of someone determined to lose weight. Odds are, they have a goal weight in mind – and aren’t working aimlessly towards a random number. The same concept goes for reducing emissions – whether it be worldwide or within a company. Emission factors provide us with numerical meaning to help monitor, measure, and assess our progress in reducing our carbon footprint and reaching our goals.
🔬
Improved Research
The numerical data provided on behalf of emission factors directly help both scientists and researchers to develop stronger environmental models, which can overall sway businesses, governments, and even entire countries to change their approach to climate change and reduce emissions.
📣
Raising Public Awareness
We know the phrase usually goes, “a picture says a thousand words”, but in this case – the information provided by emission factors is much more likely to speak volumes to society as opposed to a one picture from a single natural disaster. Therefore, emission factors are important as they help to spread the word on the importance of reducing our environmental impact.
📊
Benchmarking & Comparability
Standardized emission factors let companies and sectors compare performance on equal footing, identify leaders and laggards, and prioritize the biggest opportunities for reduction.
Overall, it is important to realize that the main benefit of emissions factors is that they quantify the impacted created by various pollutants and activities – which is vital to fuel the world and provide incentives to reduce emissions as a whole.
Examples of an Emission Factor
Some common examples of emission factors include carbon dioxide (CO₂), greenhouse gasses (GHG), methane (CH₄), and other volatile organic compounds.
Here is a breakdown of some of the most common emission factors used in society to help standardize the information associated with environmental impacts:
🌍🔥
Carbon Dioxide Emission Factors
This type of emission factor demonstrates the amount of carbon dioxide released per unit.
A common example is how many kilograms of CO₂ is released as a result of a roundtrip flight.
🐄🌫️
Methane Emission Factors
Methane emission factors illustrate how much CH₄ is emitted per unit such as with natural gas
production, decomposition, or with
livestock
.
However, it is important to note that methane emissions are not limited to these activities.
🚗💨
Nitrogen Oxides Emission Factors
These emission factors help people to understand how much NOx is released from pollutants – often
coming from vehicles or industrial warehouses. This is one reason governments encourage electric
vehicles or implement bike share programs wherever possible.
🧪🎨
Volatile Organic Compounds (VOC) Emission Factors
Sometimes referred to as VOC, volatile organic compound emission factors are used to determine
emissions from activities such as painting, using solvents, or chemical manufacturing. The strong
smell after painting comes from VOCs – and VOC emission factors measure how much is released based
on the painted surface area.
What Were the Emission Factors by Country in 2025?
The electricity emission factors by country as of 2025 are as follows, expressed in carbon dioxide emission factors:
①
🇨🇳
China
15 536.10 Mt CO₂ eq
②
🇺🇸
United States
5 912.62 Mt CO₂ eq
③
🇮🇳
India
4 371.17 Mt CO₂ eq
④
🇷🇺
Russia
2 575.65 Mt CO₂ eq
⑤
🇮🇩
Indonesia
1 323.78 Mt CO₂ eq
⑥
🇯🇵
Japan
1 063.34 Mt CO₂ eq
⑦
🇧🇷
Brazil
1 299.18 Mt CO₂ eq
⑧
🇹🇷
Turkey
579.51 Mt CO₂ eq
⑨
🇻🇳
Vietnam
584.26 Mt CO₂ eq
⑩
🇸🇦
Saudi Arabia
838.88 Mt CO₂ eq
Ultimately, without emission factors – it would be difficult to communicate basic information such as the top emitting countries in the world, seeing as emission factors provides a standardized unit that anyone can understand.
How Can You Calculate an Emission Factor?
Calculating an emission factor is dependent on the type of emission you are trying to calculate.
However, many are able to use the following formula when seeking to calculate an emission factor:
Emission Factor (EF) = Total Emissions / Total Activity
EF = (Total emissions of the pollutant) / (Total amount of activity)
The vertical timeline below will break down how to calculate an EF:
1. Define the Activity 📋
Clearly describe what you’re measuring (e.g., liters of diesel burned, kWh of electricity used, kilometers driven). This “activity data” will be the denominator in your emission factor formula.
2. Collect Activity Data 📊
Gather accurate totals for the activity over a chosen period (month, year, project). For example, sum all fuel receipts, energy bills, or production logs to find the Total Activity.
3. Measure or Estimate Emissions 🌫️
Measure how much of the pollutant was released during that same period (e.g., kilograms of CO₂, CH₄, or NOx). This can come from direct monitoring, lab analysis, or trusted published factors. This gives you the Total Emissions.
4. Align Units & Timeframe ⚖️
Make sure the units match and cover the same timeframe. If activity is in liters of fuel per year, emissions should also be for that same year and converted to consistent units (e.g., kilograms of pollutant).
5. Apply the Emission Factor Formula 🧮
Use the core calculation:
Emission Factor (EF) = Total Emissions / Total Activity
or written explicitly:
EF = (Total emissions of the pollutant) / (Total amount of activity).
Divide your measured emissions by the total activity to obtain an EF, such as
“kg CO₂ per liter of diesel” or “g CH₄ per km driven.”
6. Interpret & Use the EF 📉📈
Multiply this emission factor by new activity data to estimate future emissions, compare performance between sites or products, or identify hotspots where reductions will have the biggest impact.
7. Review, Update & Improve 🔄
Periodically repeat the calculation with fresher data, better monitoring, or improved methods. Refining the emission factor over time makes your carbon accounting more accurate and your reduction strategies more effective.
Below is a demonstration of someone calculating the emission factor for greenhouse gas emissions:
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What Are the Challenges in Emission Factors?
Some of the challenges presented with emission factors include difficulties with new technologies and varied estimates, confidentiality, and an overall lack of standardization.
Think of the SAT or ACT standardized tests, used to help students get into college in the United States. If these tests didn’t exist, colleges would have to use student’s grade point averages (GPA) as the sole numerical measure to determine if they are worthy of attending their school.
However, this is unfair seeing as the level of rigor at high schools are bound to vary across the country – demonstrating why the need for standardization is pivotal for emission factors, too.
The infographic below will further breakdown some of the challenges of turning emission factors into usable carbon data:
Additional Challenges of Emission Factors:
Here are some more challenges often presented with emissions factors:
- Inability to Collect Varied Data – Think about someone timing how fast they can run a mile – while the time may be a good estimate of one’s physical shape, the mile time isn’t expected to be exactly the same each time due to factors like how well they slept or weather conditions for running outdoors. The same goes for emissions factors, as they are often calculated using average values and do not take enough variables into account.
- Lack of Data Quality & Varied Calculations – The data retrieved when seeking to calculate emissions factors can often be compromised, and the end result is insufficient or unreliable data.
- Geographic Location – Emission factors are not usually the same across the country let alone the world, and are likely to vary depending on the geographic location and season. Therefore, emission factors developed in one region or developed to be used during a specific time period may not always best represent the emissions being produced in other areas or during different times of the year.
- New Technologies & Practices – Technology continues to develop, with AI taking the world by storm – and while this can prove beneficial for supply chains and emission reductions, these advancements in technology may deem emissions factors outdated altogether.
- Lack of Standardization – Perhaps one of the biggest struggles with emissions factors is the lack of standardization, seeing as emission factors may not be standardized across the globe or even at neighboring organizations. This makes it difficult to compare, contrast, and adequately develop climate policies or environmental regulations accordingly.
- Changes in Reporting Requirements & Compliance – Businesses and governments both rely on emissions factors in order to determine their GHG or carbon dioxide emission reduction goals. Without varied data collection or standardization, it makes it difficult for companies to set honest goals or for policy makers to pass fair climate laws.
Despite these challenges, efforts are still being made to improve emissions factors and ensure it remains a viable resources for all industries seeking to use them.
Are Emission Factors Still Worth Using?
At the end of the day, emission factors still offer an indispensable benefit – which is being able to quantify the impact created by various emissions through industrial processes, activities, energy production, transportation, and more.
While the system of emission factors may not be 100%, the system we currently use is worth keeping intact in order to numerically depict and better understand the way our everyday activities continue to have a profound effect on the planet.
The interactive flip cards (move cursor over card to flip) will reveal why emission factors are worth using despite their potential challenges:
📏 Makes Emissions Comparable
Emission factors turn messy real-world activities into standard units
(like kg CO₂ per kWh), making it easier to compare sites, suppliers,
or products—even when the underlying data comes from very different places.
📊 Fills Data Gaps Quickly
Direct measurement for every process is expensive and slow.
Using credible emission factors lets companies estimate emissions
where meters don’t exist yet, so climate reporting and action
can move forward instead of waiting for perfect data.
🎯 Supports Targets & Strategy
Because emission factors link each activity to a numeric climate impact,
they help teams model scenarios, set science-based reduction targets,
and see which levers—fuel, materials, transport, or energy efficiency—
will deliver the biggest cuts.
🧩 Enables Consistent Reporting
Standardized emission factors are embedded in most GHG protocols
and reporting frameworks. Using them—despite their limits—ensures
results are transparent, repeatable, and easier for auditors,
investors, and regulators to understand and compare over time.
What About Greenly?
If reading this article on emission factors has made you interested in reducing your carbon emissions to further fight against climate change – Greenly can help you!
Keeping track of how an emission factor could impact your business can be confusing, but don’t worry – Greenly is here to help! Click here to schedule a demo to see how Greenly can help you comply with all of the upcoming regulations relevant to your company.
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.
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