With increasing regulatory pressure, growing investor scrutiny, and ambitious net-zero commitments, understanding your company’s carbon footprint is quickly becoming a business essential.
A CO₂ assessment is the first step toward credible climate action. It allows companies to identify where emissions come from, quantify their impact, and chart a path toward reduction. It also lays the groundwork for transparent reporting, better ESG scores, and alignment with global standards like the Science-Based Targets initiative (SBTi).
This guide covers everything from the basics to methodology, reporting strategy, and practical implementation. Designed to help you navigate the carbon assessment process with clarity and confidence.
1. What is a carbon assessment for companies?
A CO₂ assessment is the process of measuring a company’s greenhouse gas (GHG) emissions. These are usually expressed in carbon dioxide equivalents (CO₂e) and cover emissions from energy use, company vehicles, travel, purchased goods, and more.
The aim is to gain visibility over your carbon footprint, identify major emission sources, and develop strategies to reduce them. Most organizations follow the GHG Protocol to ensure results are consistent and comparable.
Want to know how to conduct a carbon assessment step-by-step? Our 5-step guide can be found here.
More interested in the basics? read this beginner's guide instead.
2. What are emission factors, and where do they come from?
Emission factors convert everyday activities into measurable carbon data. For example, a liter of diesel burned releases a certain amount of CO₂; this is quantified using an emission factor.
These factors are typically sourced from the IPCC, DEFRA, or the GHG-protocol. Tools and platforms often include pre-integrated databases to simplify calculations based on geography or industry.
Read our blog posts to learn more about the science behind emission factors and global warming.
3. What are Scope 1, 2, and 3 emissions?
Emissions are categorized into three "scopes":
Scope 1: Direct emissions from company-owned sources (e.g. fuel combustion in company vehicles).
Scope 2: Indirect emissions from purchased electricity, heating, or cooling.
Scope 3: All other indirect emissions, including those from your supply chain, employee commuting, travel, waste, and product use.
Scope 3 is often the most significant and difficult to measure; but it offers the greatest opportunity for systemic change.
For a deep-dive into scope 1-2-3 emissions, read this article.
4. How accurate does the data need to be?
Perfect accuracy isn’t expected. What's more important is transparency. The GHG Protocol recommends using the best available data and documenting any assumptions or proxies.
In early assessments, companies may rely on spend-based estimates or industry averages. Over time, data quality can be improved through better tracking systems, employee engagement, and supplier collaboration.
More info about the GHG Protocol can be found here.
5. Can software help with carbon assessments?
Software can significantly streamline the process. It can help you collect and organize data, apply emission factors automatically, and generate reports aligned with standards like CSRD or SBTi.
Some tools also offer templates, dashboards, and integrations with procurement or finance systems; making the process more efficient and repeatable. Whether you build internally or use an external platform depends on your data maturity and reporting goals.
Curious which carbon assessment tool best fits with the needs of your company? Read our blog about the top 10 best carbon footprint calculators. Or explore what our tool has to offer.
6. Is a carbon assessment mandatory?
It depends on your location and business size. In the EU, companies covered by the CSRD must disclose Scope 1, 2, and 3 emissions.
To learn more about the CSRD, read this article.
7. Why should companies assess their CO₂ emissions?
A CO₂ assessment offers insights that can drive operational efficiency, cost savings, and risk reduction. It’s also foundational for ESG reporting and increasingly expected by customers, investors, and employees.
Assessments help businesses identify their most material climate impacts, comply with frameworks like CDP, and unlock opportunities for innovation and long-term resilience.
8. How often should a company do a carbon assessment?
Most companies conduct assessments annually, aligned with financial and ESG reporting cycles.
Some perform quarterly or ongoing monitoring for high-impact areas like logistics or travel. Frequent tracking enables quicker feedback loops and helps companies stay on course toward climate targets.
9. How can you get the most value from your carbon assessment?
To unlock the full value of a CO₂ assessment, don’t stop at measurement. Use the results to set science-aligned targets, prioritize reductions, and embed climate thinking across procurement, operations, and product development. The most effective assessments are those that lead to action; not just reporting.
Make sure your carbon assessment delivers value; read our ultimate guide.
10. What is the relationship between a carbon assessment and a carbon audit?
While a CO₂ assessment is the internal act of collecting data and calculating emissions, a carbon audit is a third-party verification of that process.
Audits help validate the methodology, check data integrity, and confirm that the assessment complies with frameworks such as ISO 14064 or CDP. This can be particularly valuable for companies required to disclose their climate performance or seeking to build credibility with stakeholders.
11. How do carbon assessments link to ESG?
CO₂ assessments feed directly into the Environmental (E) pillar of ESG. The data generated supports disclosures under frameworks like GRI, SASB, and SBTi.
They also help improve ratings from agencies such as MSCI, making them a valuable lever for investor relations and sustainable finance.
12. Can carbon assessments align with Science-Based Targets (SBTi)?
Yes. An SBTi-aligned climate strategy starts with a reliable emissions baseline.
The Science-Based Targets initiative requires companies to measure Scope 1, 2, and often Scope 3 emissions, then set targets in line with the Paris Agreement’s 1.5°C pathway. A thorough assessment ensures your targets are credible, verifiable, and backed by data.
13. What standards exist for carbon accounting?
Carbon accounting is governed by several international frameworks, including:
GHG Protocol – the most widely used global standard
ISO 14064– for verified environmental management
PCAF – used by financial institutions for portfolio-level accounting
Adhering to a recognized standard increases the comparability and transparency of your emissions data.
14. What's the difference between spend-based and activity-based assessments?
Spend-based: Uses financial data (e.g. euros spent on travel) and multiplies by an average emission factor. It’s quick and useful when detailed activity data isn’t available.
Activity-based: Uses actual usage data (e.g. kilometers driven, kWh consumed) for more accurate results.
The GHG Protocol supports both methods. Many companies start with spend-based estimates and move toward activity-based approaches as data quality improves.
15. Summary
A Carbon assessment is more than just a compliance tool; it’s the starting point for meaningful climate strategy. By measuring and understanding emissions, businesses can reduce risks, cut costs, and build trust with stakeholders.
As expectations for transparency and accountability continue to grow, having reliable emissions data is critical. Whether you’re preparing for CSRD, aligning with SBTi, or improving your ESG standing, a robust Carbon assessment gives you the foundation you need to act with purpose.
How Regreener helps you with carbon assessment
If you're looking for a structured and efficient way to measure and reduce your carbon emissions, Regreener’s Footprint Navigator is built to support you at every step. The tool helps companies collect relevant data across Scope 1, 2, and 3 emissions, apply trusted emission factors, and generate actionable insights.
Whether you're conducting your first assessment or building a climate strategy aligned with CSRD or SBTi, Regreener offers the expertise, templates, and guidance to make the process clear and impactful. You’ll also gain access to integrated offsetting options and reporting features that help you track progress and share results with stakeholders.
