Google Cloud Carbon Footprint holds a clear lead for software platform carbon intensity tracking. However, assessments focused strictly on machine learning compute show no single preferred provider.
Yes. For ESG reporting, I’d separate “software carbon intensity” from “electricity/grid carbon intensity” and use the former as the reporting methodology and the latter as an input.
Best sources
Source
What you get
ESG/reporting suitability
Green Software Foundation — SCI
Software Carbon Intensity (SCI), including operational + embodied emissions per functional unit
This is probably the most defensible starting point if you're specifically reporting the carbon intensity of a software platform. SCI is ISO/IEC 21031:2024 and expresses emissions as a rate rather than simply a yearly total.
The core calculation is:
SCI = (E × I + M) / R
where:
E = energy consumed
I = electricity carbon intensity
M = embodied emissions of the hardware
R = functional unit, such as API call, transaction, user, or job
The specification explicitly recommends documenting the software boundary, functional unit, measurement/modeling approach, and calculation methodology—exactly the kind of documentation you want for ESG assurance.
For a SaaS platform, for example, I would consider gCO₂e per 1,000 API calls, gCO₂e per transaction, or gCO₂e per active user-month, depending on what best represents your platform's activity.
2. Use your cloud provider's actual emissions data where possible
If your software runs primarily in a public cloud, provider-specific data is preferable to simply applying a generic "kWh × grid factor" estimate.
AWS: Its Customer Carbon Footprint Tool provides emissions by AWS Region and has export functionality. AWS says its current methodology uses the GHG Protocol, ISO 14040/44, ISO 14067 and ICT-sector guidance, among other standards.
Google Cloud: Carbon Footprint provides customer-specific emissions by project, product and region, with both location-based and market-based reporting. Google publishes the calculation methodology, although it explicitly notes that the customer-specific data has not been third-party verified/assured.
Azure: Microsoft's Carbon Optimization provides emissions at resource/resource-group level, with API and CSV access. Microsoft also publishes its methodology, including how Azure emissions are allocated to customers.
3. For the electricity-intensity input, use authoritative grid data
For U.S. workloads, the EPA eGRID/emission-factor datasets are a good foundation. EPA publishes electricity factors by eGRID subregion, including CO₂, CH₄ and N₂O factors.
For SCI, however, don't automatically substitute an annual average electricity factor. The SCI specification is explicitly concerned with region-specific carbon intensity, and its methodology can accommodate location- and time-sensitive intensity.
That's where a source such as WattTime can become useful for more granular marginal-emissions calculations.
Software activity → energy consumption → grid carbon intensity → operational CO₂e → embodied hardware emissions → SCI per functional unit
And report both:
Absolute emissions: e.g. tCO₂e/year attributable to the platform.
Intensity: e.g. gCO₂e/1,000 transactions.
Then document:
software/system boundary
cloud providers and regions
electricity-factor source and vintage
location-based vs. market-based treatment
energy measurement vs. modeled energy
embodied-carbon methodology
functional unit
allocation methodology
reporting period
assumptions and exclusions
That distinction matters because SCI is not itself a replacement for your GHG Protocol inventory. It's a software-specific intensity metric that can complement the organization's Scope 1/2/3 accounting. The cloud providers' methodologies similarly map their emissions to customer Scope 3 in different ways.
My recommendation: If this is going into a formal ESG disclosure, use SCI (ISO/IEC 21031:2024) as the software-intensity framework, provider-specific measured emissions wherever available, and authoritative grid factors for gaps. Avoid relying on a generic "carbon per page view/API call" number from a commercial sustainability calculator unless you can independently document its boundaries and factors.
If you tell me what kind of software platform you have (SaaS, mobile app, AI platform, web platform, etc.) and whether you're on AWS/Azure/GCP/on-prem, I can also give you a concrete ESG-ready metric specification and data sources for calculating it.
Finding reliable carbon intensity metrics for software platforms—often categorized under Scope 3, Category 1 (Purchased Goods & Services) or Category 11 (Use of Sold Products)—requires looking at standardized calculation frameworks rather than relying solely on generalized vendor claims.
The primary, most reliable frameworks and sources for software carbon metrics include:
The Software Carbon Intensity (SCI) Specification (ISO/IEC 21031:2024)
What it is: Developed by the Green Software Foundation , this is an ISO-accredited standard specifically designed to score software carbon efficiency.
Why they are reliable: They provide granular, location-based and market-based greenhouse gas (GHG) emissions data tied to the specific data centers running your software workloads.
Greenhouse Gas (GHG) Protocol Guidance
What it is: The GHG Protocol sets the foundational global standards for corporate carbon accounting.
Why it’s reliable: For software platforms, their technical guidance on Scope 3 emissions helps translate cloud hosting data and IT equipment lifecycles into auditable metrics accepted by ESG regulators (like CSRD or SEC climate disclosure rules).
Sourcing verified carbon intensity data for software platforms—especially when building investor-grade, audit-ready ESG disclosures—requires combining standardized calculation methodologies with validated grid emission factors and cloud telemetry.
2. Primary Data Sources for Grid Carbon Intensity (I)
For the grid carbon intensity component (gCO2eq/kWh) tied to where your software/cloud servers physically execute, use verified regional grid telemetry:
Electricity Maps / Tandem / WattTime: These provide real-time and historical marginal or average carbon intensity data for global electricity grids. Auditors widely accept them because they offer granular, location-based emission factors tied to specific data center regions (e.g., us-east-1 vs. eu-west-1).
Open-Source Telemetry Tooling: To measure workloads at a granular level for your SCI score, integrate tools like Cloud Carbon Footprint (an open-source tool that translates cloud billing metrics into energy and carbon estimates).
If your company needs to bundle software carbon data alongside broader Scope 1, 2, and 3 disclosures into an assurance-ready package for regulators (such as the CSRD or SEC climate rules), enterprise platforms with robust audit trails and embedded factor libraries include:[](https://www.seedling.earth/post/best-carbon-management-software-platforms)
Watershed (Deep tech-sector adoption and extensive emission factor libraries)
Persefoni (Investor-grade carbon ledger with strict accounting controls)
Yes. For ESG disclosures, I’d distinguish between actual provider-specific emissions data and generic “carbon intensity” factors. The strongest sources are the former, because they let you tie emissions to your company’s actual software/cloud usage.
Best sources
Source
Best use
Audit defensibility
AWS Sustainability
AWS workloads and services
Very high — AWS says its current methodologies are independently verified and aligned with recognized standards.
For ESG reporting on software platforms, I’d recommend combining recognized emissions-accounting standards, authoritative electricity carbon-intensity data, and cloud-provider-specific emissions reports rather than relying on a single generic dataset.
The key distinction is that electricity carbon intensity (grams of CO₂-equivalent per kWh) is not the same as a software platform’s total carbon footprint. To estimate the latter, you also need information about compute, storage, networking, data-center efficiency, and potentially hardware manufacturing.
1. Best datasets and sources to start with
1. Electricity Maps
(Best for grid intensity)
Provides regional and historical electricity carbon intensity, including hourly data, flow-traced consumption-based values, and lifecycle emissions factors. Its API supports data-center provider and region parameters for supported use cases.
Use for: Estimating emissions from electricity consumed by workloads in specific regions.
Strength: Detailed temporal and geographic coverage, documented methodology.
Caveat: Verify coverage, licensing, and whether the required historical data is available for commercial reporting.
Provides customer-specific greenhouse gas emissions estimates allocated to Google Cloud products and customer usage. Google documents its calculation methodology and data sources.
Use for: Reporting emissions from workloads hosted on Google Cloud.
Strength: Provider-specific allocation is more useful than applying a generic grid factor to cloud spend.
Caveat: Understand the reporting boundary, calculation updates, and whether the figures cover the emissions categories required by your ESG framework.
Link:
3. Cloud Carbon Footprint
An open-source tool that estimates emissions for AWS, Microsoft Azure, and Google Cloud using usage or billing data, energy conversion factors, power usage effectiveness (PUE), and grid emissions factors. Its methodology also discusses embodied hardware emissions.
Use for: Cross-cloud estimates when provider reports are incomplete or you need a consistent internal methodology.
Strength: Transparent, inspectable methodology and configurable estimation logic.
Caveat: The project explicitly describes its estimates as experimental and not a substitute for provider data.
Link:
4. U.S. EPA eGRID
A public dataset covering emissions, emission rates, generation, and electricity resource mix across the U.S. power sector. The currently listed dataset includes 2023 data.
Use for: A transparent U.S. electricity emissions baseline when you know the data-center region or relevant grid subregion.
Strength: Government-produced, downloadable data and technical documentation.
Caveat: Annual grid-average factors won't capture hourly variation, and grid subregions may not precisely match cloud regions.
Link:
5. UK Government GHG Conversion Factors
The 2026 publication includes downloadable conversion factors and methodology documentation for organizational emissions reporting, including electricity and other activity-based calculations.
Use for: UK operations, supplier activity data, and broader corporate emissions inventories.
Strength: Official, updated annually, with machine-processable files.
Caveat: Use the factors applicable to the relevant geography and activity; UK factors aren't a universal substitute for global grid data.
Link:
6. AWS Sustainability
AWS's current sustainability service provides estimated emissions associated with AWS usage, with documented calculation methodology and emissions broken down by account, region, and other dimensions. Its estimates include Scope 1, Scope 2, and Scope 3 categories.
Use for: Cloud infrastructure emissions reporting for AWS workloads.
Strength: Service-specific data, documented methodology versions, and export options.
Caveat: Confirm which emissions categories and allocation assumptions apply to your reporting period.
The sources above provide data or estimates; these references help establish how you should use them in a defensible ESG inventory.
- GHG Protocol — Scope 2 Guidance. Defines location-based versus market-based accounting for purchased electricity. This distinction matters when reporting the electricity footprint of your own operations or applying emissions factors to software infrastructure.
- GHG Protocol — Standards and guidance library. Start here for the Corporate Standard and Scope 3 guidance if your report includes purchased cloud services, software suppliers, or a product-level footprint.
4. How to make the data defensible for ESG reporting
I would implement the following process.
Define the reporting boundary. Identify whether you're reporting your company's cloud usage, the footprint of a software product delivered to customers, or your organization's full value chain. These are different accounting questions.
Prefer activity-based inputs. Use actual cloud resource consumption, provider emissions exports, electricity usage, and data-center region wherever possible. Treat spend-based estimates as a fallback rather than the preferred method.
Choose the appropriate emissions factor. Match geography, reporting period, units, and lifecycle boundary. Don't multiply cloud-provider emissions by a grid factor again if the provider's reported figure already incorporates that factor.
Separate accounting methods and emissions categories. Keep location-based and market-based figures distinct where applicable. Document how Scope 1, Scope 2, and relevant Scope 3 emissions are included and allocated.
Preserve an audit trail. Record the source URL, dataset version, publication date, retrieval date, factor units, assumptions, estimation flags, allocation methodology, and any subsequent restatements.
One important caveat: a trustworthy grid-intensity dataset alone cannot establish the full footprint of a software platform. You also need a defensible estimate of energy consumption and a clear boundary for hardware embodied emissions, upstream suppliers, and other relevant activities.
5. Let’s narrow this to your use case
The best dataset depends heavily on what you mean by software platform. For example, a SaaS company reporting its own cloud footprint needs different data from a company comparing the lifecycle emissions of software products.
What are you trying to measure?
Emissions attributable to a SaaS product or platform
Our own cloud infrastructure footprint
Emissions from software vendors and purchased services
Comparative lifecycle footprint of software products
Trustworthy, audit-ready carbon intensity data sets and platforms fit for ESG disclosures include the following options:
Electricity Maps provides real-time, historical, and forecasted marginal and average grid carbon intensity data for over 150 countries. It features peer-reviewed tracking of cross-border electricity flows and import/export adjustments, making it a gold standard for precise location-based Scope 2 calculations. It offers direct API access and integrates cleanly with carbon-aware tooling.[](https://github.com/electricitymaps/if-electricitymaps)
is an open-source tool supported by a prominent community that translates cloud infrastructure usage (AWS, GCP, Azure) into estimated energy and CO₂ equivalents. It relies on built-in emission factors sourced from reputable government and international research bodies, and it allows seamless integration with the API for live regional intensity data.[](]()]()
Google Cloud Carbon Footprint
GCP workloads
High — provides customer-specific emissions by project/product/region and both location- and market-based figures.
Microsoft Azure emissions methodology
Azure and Microsoft 365
High — Microsoft documents Scope 1/2/3 calculation methodology for Azure and M365.
GHG Protocol
Reporting/accounting framework
Essential — use it to determine whether the provider data belongs in Scope 2 or Scope 3 and how to report it.
Cloud Carbon Footprint
Multi-cloud estimation when provider data isn't sufficient
Medium — useful and transparent/open source, but generally an estimation layer rather than primary provider data.
1. Prefer the cloud provider's own customer-level data
If your software platform runs on AWS, Azure, or Google Cloud, use the provider's allocated emissions data rather than applying a generic kgCO₂e/kWh factor to your cloud bill whenever possible.
For example, AWS's current methodology allocates data-center emissions down through clusters → services → individual customer accounts, using physical allocation where possible and economic allocation where necessary.
AWS also says its current sustainability methodologies have been independently verified.
For Google Cloud, Carbon Footprint provides emissions associated with your actual Google Cloud usage and can report them at project, product, and region levels. Google explicitly provides both location-based and market-based figures.
Microsoft documents its Azure/Microsoft 365 emissions methodology, including emissions associated with hardware manufacture, transportation, use and end-of-life.
If your company buys a SaaS product—say CRM, HR, collaboration, analytics, or developer software—you ideally want the SaaS vendor's product-level carbon footprint or allocated emissions, not a generic cloud intensity factor.
Ask the vendor for:
kgCO₂e attributable to your usage, preferably monthly/annual
Scope 1, 2 and relevant Scope 3 components
Allocation methodology
Data-center/cloud regions included
Whether electricity is calculated using location-based or market-based factors
Whether embodied hardware emissions are included
Reporting period and emission-factor vintage
Any independent assurance/verification
Whether the figure follows GHG Protocol, ISO 14067, ISO 14040/44, or the Green Software Foundation SCI methodology
If the vendor cannot provide this, you can build an estimate from their infrastructure footprint, but I would label it clearly as estimated, rather than presenting it as measured/verified emissions.
3. Use Green Software Foundation's SCI for software-level intensity
If what you actually need is “carbon intensity of this software platform” rather than corporate Scope 1/2/3 emissions, look at the Software Carbon Intensity (SCI) Specification from the Green Software Foundation.
SCI is particularly useful for expressing something like:
grams CO₂e per user transaction / API call / GB processed / software functional unit
rather than simply reporting total organizational emissions.
Cloud Carbon Footprint, for example, incorporates elements of the SCI approach when estimating embodied emissions.
4. Use Cloud Carbon Footprint for multi-cloud estimation
Cloud Carbon Footprint is a useful open-source option if you need a consistent methodology across AWS, Azure and GCP.
It takes cloud usage data, estimates energy consumption, incorporates data-center PUE and applies regional carbon intensity. It also exposes regional emissions factors through its API.
The important caveat: I would treat this as a secondary estimation source when the cloud provider gives you customer-specific emissions. Its own documentation acknowledges that some approaches estimate energy consumption rather than measuring it directly.
What I'd recommend for an ESG disclosure
I'd establish a hierarchy like this:
Tier 1 — Preferred
Vendor/customer-specific emissions data + documented methodology + independent assurance
Tier 2 — Strong
Provider-specific emissions calculation using actual usage + published methodology
Tier 3 — Acceptable estimation
Actual software/cloud consumption × geographically appropriate emissions factor
Tier 4 — Screening estimate
Spend-based or generic software-sector emissions factor
And keep the activity data, factor, methodology version, source, geography, reporting period and calculation in your ESG evidence file so an auditor can reproduce the number.
One particularly important distinction: don't automatically call software/cloud emissions “Scope 2.” GHG Protocol Scope 2 is about purchased/acquired electricity, heat, steam and cooling; cloud-provider emissions attributable to your company's use can involve Scope 3 treatment depending on the boundary and accounting methodology.
If you're building this into an actual ESG disclosure methodology, I can also give you a source hierarchy and data schema for software carbon intensity (e.g., vendor → product → region → kWh → kgCO₂e → scope → factor → assurance) that would be suitable for audit evidence.
WattTime offers automated, highly granular marginal operating emissions rate (MOER) data sets. While average grid intensity is typical for standard annual ESG reporting, WattTime’s marginal intensity data is widely trusted for advanced software workloads aiming for time-flexible, carbon-aware computing.
Enterprise Carbon Accounting & ESG Platforms (such as Workiva, Watershed , or Sweep ) embed validated emission factor databases directly into their compliance suites. These platforms map cloud and data center utilization metrics directly against recognized reporting frameworks (like the GHG Protocol, CSRD, and ISSB) with built-in audit trails.[](https://sustainabilitymag.com/top10/top-10-sustainability-reporting-platforms)
If you'd like, let me know:
Whether you are tracking on-premise data centers or public cloud providers (AWS, Azure, GCP)
If you need data for annual regulatory reporting or real-time carbon-aware optimization
I can help narrow down the most appropriate data integration path for your stack.