ESG Carbon Footprint Tracker for Devs
Calculate the CO2 footprint of your cloud deployment and estimate offset costs.
ESG Scope 1-3 Carbon Tracker
Estimate greenhouse gas (GHG) emissions for tech companies based on operations.
ESG Reporting: Standardized TCFD and ISSB disclosures require Scope 3 value chain transparency. Cloud compute emissions are a dominant factor for modern SaaS firms, often exceeding direct facility (Scope 1) impact by 400%.
| Scope | MT CO₂e | % |
|---|---|---|
| Scope 1 (Direct) | 5.30 | 7% |
| Scope 2 (Indirect) | 57.75 | 82% |
| Scope 3 (Chain) | 7.70 | 11% |
15
Cars/Year
2,830
Trees/Decade
Why Scope 1, 2, and 3 Mean Something Different for SaaS Companies Than for Industrial Emitters
The GHG Protocol Corporate Standard defines three emission scopes, but their relative significance varies dramatically by industry. For a cement manufacturer, Scope 1 — direct combustion emissions from kilns — dominates. For a SaaS company, Scope 1 is typically negligible: unless you operate your own diesel generators or gas-heated offices, you have almost no direct combustion. Your emissions profile is dominated by Scope 2 (purchased electricity for offices and owned data centres) and Scope 3 (cloud infrastructure operated by third parties, employee business travel, commuting, and purchased goods and services). For a typical SaaS company using major cloud providers, Scope 3 Category 1 (purchased services, specifically cloud compute and storage) accounts for 60 to 90 percent of total emissions footprint — a figure that most generic carbon calculators either ignore or treat as optional. The ISSB IFRS S2 standard, which became effective for reporting periods beginning January 2024, and the EU CSRD with mandatory ESRS E1 reporting, both require Scope 3 disclosure for companies above the reporting threshold. The shift from voluntary to mandatory Scope 3 reporting means SaaS companies can no longer report only their office electricity as their carbon footprint. This tool is designed around the SaaS emissions structure specifically: cloud compute as the primary Scope 3 source, travel as the secondary Scope 3 source, and office energy as the Scope 2 source, rather than the industrial-process structure that most enterprise carbon accounting tools assume.
How Cloud vCPU Hours Map to CO2 Emissions
Cloud providers do not directly report per-customer emissions in real time, but the methodology for estimating them from usage data is established in GHG Protocol Scope 3 Technical Guidance and the Cloud Carbon Footprint open-source methodology. The calculation has three components: first, the energy consumed by your compute resources, estimated as vCPU count times utilisation rate times the server power usage per vCPU (typically 2 to 10 watts per vCPU depending on instance type and workload characteristics); second, a PUE multiplier for the data centre overhead, which for hyperscale providers is typically 1.10 to 1.20; and third, the carbon intensity of the electricity grid in the region where your cloud region is located. AWS publishes regional carbon intensity figures in its Customer Carbon Footprint Tool. Google Cloud publishes carbon-free energy percentages by region and net carbon intensity after renewable purchases. Microsoft Azure publishes Scope 1 and 2 emissions for its data centre portfolio. This tool uses representative regional emission factors derived from IEA grid data and publicly available cloud provider disclosures. The output — kilograms of CO2 equivalent per year from cloud usage — is a Category 1 Scope 3 purchased services emission and must be disclosed under IFRS S2 and ESRS E1 when the company meets the reporting threshold.
Worked Example: 50-Person SaaS Company Preparing Its First ISSB Report
Consider a 50-person SaaS company based in London running its production infrastructure on AWS eu-west-1 (Ireland) and using a leased office in central London. Cloud usage: 200 vCPUs at 40 percent average utilisation running continuously. Estimated server power per vCPU at that utilisation level is approximately 4 watts. Total server power draw: 200 times 0.4 times 4 equals 320 watts, or 0.32 kW. With a data centre PUE of 1.12 (AWS Ireland achieves approximately 1.10 to 1.14): 0.32 times 1.12 equals 0.358 kW of total facility power for this workload. Annual energy: 0.358 times 8,760 equals 3,136 kWh. Ireland grid carbon intensity is approximately 0.295 kg CO2 per kWh (IEA 2023 data). Annual cloud Scope 3 emissions: 3,136 times 0.295 equals approximately 925 kg CO2e — just under one tonne. Office Scope 2: a 50-person London office consuming approximately 50,000 kWh per year at the UK grid intensity of 0.207 kg CO2 per kWh produces approximately 10,350 kg CO2e annually. Business travel Scope 3: 50 employees averaging 3 return long-haul flights per year at approximately 1,200 kg CO2e per return long-haul flight gives 50 times 3 times 1,200 equals 180,000 kg CO2e. In this profile, business travel — not cloud infrastructure — is the dominant emission source at 93 percent of the total. The practical implication is that flight reduction programmes deliver more emissions reduction per pound of effort than cloud efficiency optimisation for this company size and travel intensity.
Frequently Asked Questions
Commonly Asked Questions
- What is the difference between TCFD, ISSB IFRS S2, and EU CSRD for emissions disclosure?
- TCFD (Task Force on Climate-related Financial Disclosures) is a voluntary framework that became the basis for regulatory requirements globally. ISSB IFRS S2 is the International Sustainability Standards Board's climate disclosure standard, effective for reporting periods from January 2024, adopted as mandatory by the UK, Australia, Singapore, and other jurisdictions with more adopting in 2025 and 2026. It requires Scope 1, 2, and 3 emissions disclosure for companies meeting the reporting threshold, which for IFRS S2 is companies already subject to IFRS financial reporting. EU CSRD with ESRS E1 applies to large EU-listed companies and large companies operating in the EU above defined revenue, balance sheet, and employee thresholds — approximately 50,000 companies in scope by 2025. ESRS E1 requires gross Scope 1, 2, and 3 disclosure alongside intensity metrics and net-zero target disclosure. All three frameworks reference the GHG Protocol Corporate Standard as the calculation methodology. If your company is subject to ISSB or CSRD, TCFD compliance is automatically achieved as TCFD is a subset of both.
- Which Scope 3 categories are most relevant for a SaaS company?
- GHG Protocol defines 15 Scope 3 categories. For SaaS and tech companies the material ones are: Category 1 (purchased goods and services) — cloud compute, SaaS subscriptions used as inputs, and professional services; Category 6 (business travel) — flights, hotels, and ground transport for employees; Category 7 (employee commuting) — daily travel to office locations; and Category 11 (use of sold products) — the energy consumed by customers using your software, which is relevant if your product runs on customer hardware rather than cloud infrastructure you control. Categories 2 through 5 and 8 through 15 are typically immaterial for asset-light SaaS businesses with no manufacturing, physical distribution, or significant capital goods. ESRS E1 requires disclosure of all material Scope 3 categories with an explanation of why immaterial categories were excluded.
- How do I get actual cloud carbon data rather than an estimate?
- AWS provides the Customer Carbon Footprint Tool in the Billing console, which reports monthly Scope 1, 2, and 3 emissions from your AWS usage using AWS's internal emissions factors. Google Cloud provides Carbon Footprint reporting in the Cloud Console. Microsoft Azure provides the Emissions Impact Dashboard in the Azure portal. These tools produce more accurate figures than manual estimation because they apply instance-type-specific power models and actual regional grid data. The tool you are using now is designed for initial estimates and scenario modelling when you do not have console access or are evaluating cloud region choices before committing infrastructure. For formal disclosure, use the cloud provider's own reporting tool and cite it as the data source in your methodology notes.
- What carbon intensity figure should I use for cloud compute in my disclosure?
- For location-based Scope 3 accounting — required as the baseline under GHG Protocol and ESRS E1 — use the grid average carbon intensity for the region where your cloud infrastructure runs, sourced from IEA or your national grid operator's published figures. For market-based accounting — which allows you to subtract renewable energy certificates purchased by your cloud provider — use the residual mix intensity published by your cloud provider in its sustainability report or the Carbon Disclosure Project submission. AWS, Google, and Microsoft all publish market-based intensity figures reflecting their renewable purchase agreements. The difference can be significant: AWS us-east-1 on a location basis is approximately 0.35 kg CO2 per kWh; on a market basis, after Amazon's renewable purchases, it may be closer to 0.10 kg CO2 per kWh. Both figures must be disclosed under ESRS E1 — you cannot report only the market-based figure.
- Does employee commuting need to be included in the carbon footprint?
- Under GHG Protocol Scope 3 Category 7 and ESRS E1, employee commuting is a required disclosure category if material. For remote-first SaaS companies with small office footprints, commuting may be immaterial relative to business travel and cloud emissions and can be excluded with documented justification. For companies with large office-based workforces, commuting can be a significant source — a 200-person team commuting by car in a car-dependent city may generate more emissions than all cloud infrastructure. The standard approach for commuting estimation is a workforce survey asking employees for their primary commute mode and distance, which you then multiply by modal emission factors from DEFRA (for UK reporting) or EPA (for US reporting). This tool provides a simplified commuting estimate based on office headcount and an average commute assumption that you can adjust.
- What is the reporting threshold for CSRD and ISSB that determines whether my company must disclose?
- EU CSRD applies in phases. From financial year 2024, it applies to large EU public-interest entities already subject to NFRD. From financial year 2025, it applies to large companies meeting two of three thresholds: more than 250 employees, more than 40 million euros in net turnover, or more than 20 million euros on the balance sheet. From financial year 2026, it applies to listed SMEs. Non-EU companies with EU net turnover above 150 million euros and at least one large EU subsidiary or branch are in scope from financial year 2028. ISSB IFRS S2 applies based on the local jurisdiction's adoption — UK large and listed companies are subject from 2025, with proportionality provisions for smaller companies. If you are below all CSRD thresholds and not in an IFRS S2 jurisdiction, voluntary disclosure aligned with TCFD remains best practice and is increasingly required by enterprise customers in procurement questionnaires and by lenders in ESG-linked financing.
- How does this tool's output connect to a net-zero target or science-based target?
- The Science Based Targets initiative (SBTi) Corporate Standard requires companies to set emissions reduction targets consistent with 1.5 degrees Celsius warming pathways and covering all material Scope 1, 2, and 3 categories. A validated SBTi target requires a baseline year emissions inventory — which this tool helps you produce — and a reduction target expressed as a percentage reduction from that baseline by a target year, with interim milestones. The SBTi Corporate Net-Zero Standard additionally requires achieving near-zero emissions and neutralising any residual emissions with permanent carbon removal (not offsets) by 2050. The first step in any net-zero programme is establishing the baseline inventory. This tool's output — total Scope 1, 2, and 3 CO2 equivalent per year broken down by source — is the input to the SBTi target-setting process and the baseline year figure that will be cited in your net-zero commitment disclosure.