Inferensys

Guide

How to Calculate Scope 2 and 3 Emissions for AI Workloads

Go beyond direct energy use to account for the complete carbon footprint of your AI operations. This advanced guide details methodologies for calculating Scope 2 emissions (purchased electricity) using location-based and market-based methods, and Scope 3 emissions (embodied carbon in hardware, cloud provider infrastructure). We'll use real-world examples with cloud carbon footprint tools and discuss allocation strategies for shared resources.
Developer demonstrating multi-agent tool use, agent tool selection interface on laptop, casual tech demo moment.

Go beyond direct energy use to account for the complete carbon footprint of your AI operations. This advanced guide details methodologies for calculating Scope 2 emissions (purchased electricity) using location-based and market-based methods, and Scope 3 emissions (embodied carbon in hardware, cloud provider infrastructure). We'll use real-world examples with cloud carbon footprint tools and discuss allocation strategies for shared resources.

Scope 2 emissions account for the indirect carbon from the electricity your AI workloads consume. You must calculate this using both a location-based method (using the grid's average carbon intensity where your data center operates) and a market-based method (using the carbon intensity of the specific renewable energy contracts your provider has purchased). Tools like the Cloud Carbon Footprint project automate these calculations by pulling energy data from AWS, Google Cloud, and Azure APIs, applying the correct regional emission factors. This data is foundational for Setting Up a Carbon Footprint Baseline for Your AI Portfolio.

Scope 3 emissions are the most complex, covering all other indirect impacts. For AI, this includes the embodied carbon in your GPU hardware (manufacturing, shipping) and the upstream emissions from your cloud provider's infrastructure buildout. Calculate hardware emissions using lifecycle assessment databases or APIs like Boavizta. For cloud infrastructure, you must apply an allocation strategy (e.g., based on vCPU-hours) to your provider's reported corporate Scope 3 data. Integrating these figures is critical for comprehensive AI Energy Scoring and Standardized Disclosure and requires robust Automated AI Energy Data Collection.

EMISSIONS ACCOUNTING

Key Concepts: GHG Protocol for AI

Master the GHG Protocol's framework to measure the complete carbon footprint of your AI workloads, from purchased electricity to the embodied carbon in your hardware.

03

Scope 3: Cloud Provider Infrastructure

This is a critical, often overlooked Category 3: Fuel- and Energy-Related Activities emission. When you use cloud services, you are responsible for a share of the emissions from the construction and operation of the cloud provider's data centers.

  • Cloud providers are increasingly disclosing these infrastructure carbon factors.
  • Calculation requires allocation. You must allocate a portion of the provider's total data center emissions to your specific usage, typically based on your share of energy consumption or compute time. This moves your accounting beyond just the electricity your VMs use (Scope 2) to include the carbon cost of the building, cooling systems, and networking gear that enable your workloads.
~10%
Of cloud emissions can be infrastructure
04

Allocation Strategies for Shared Resources

A core challenge in Scope 3 calculation is fairly dividing emissions from shared resources (e.g., a GPU cluster used by multiple teams/models). Use these standard allocation methods:

  • Time-based: Allocate emissions based on the duration of exclusive use (e.g., GPU-hours). Best for training jobs.
  • Utilization-based: Allocate based on average hardware utilization (e.g., % of GPU memory or SM activity). More accurate for inference workloads.
  • Economic-based: Allocate based on the cost attributed to each workload. Often used for high-level financial reporting. Document your chosen methodology consistently. Inconsistent allocation is a common mistake that invalidates year-over-year comparisons.
05

Market-Based vs. Location-Based in Practice

Understanding the difference between these two Scope 2 methods is non-negotiable for credible reporting.

  • Location-based gives you a baseline footprint. It answers: 'What were the emissions of the grid I physically plugged into?'
  • Market-based shows your strategic impact. It answers: 'What emissions am I responsible for based on the clean energy I chose to buy?' Best Practice: Report both numbers. The market-based figure can be lower if you have renewable contracts, but the location-based figure reveals your physical impact and dependency on the local grid's carbon intensity. This dual reporting is required by the GHG Protocol Corporate Standard for comprehensive disclosure.
AI ENERGY SCORING

Step 1: Calculate Scope 2 with Location-Based Method

The location-based method is the foundational approach for calculating Scope 2 emissions from purchased electricity for AI workloads. It uses the average carbon intensity of the local power grid where your compute is located.

The location-based method calculates emissions by multiplying your AI workload's electricity consumption (kWh) by the grid emission factor (kg CO₂e/kWh) for the region of your data center. This factor is an average for the entire local grid, published by sources like the International Energy Agency (IEA) or your national energy agency. For example, running a 100 kWh training job in a US-East region with a factor of 0.38 kg CO₂e/kWh results in 38 kg of Scope 2 emissions. This method provides a standardized, geographically accurate baseline, essential for establishing your initial carbon footprint as detailed in our guide on Setting Up a Carbon Footprint Baseline for Your AI Portfolio.

To implement this, you must first collect granular energy data. Use cloud provider tools like the AWS Customer Carbon Footprint Tool, Google Cloud Carbon Footprint, or Microsoft Emissions Impact Dashboard to get usage reports. For on-premises clusters, integrate with data center power distribution units (PDUs). Multiply the kWh values by the correct regional emission factor. Automate this calculation in your MLOps pipeline to attach a carbon cost to every training job and inference hour, creating the foundational data layer for a comprehensive AI Lifecycle Energy Monitoring System.

SCOPE 3 CALCULATION

Allocation Methods for Shared Resources

Methods for apportioning the embodied carbon of shared cloud infrastructure (Scope 3, Category 1: Purchased Goods and Services) to specific AI workloads.

Allocation MetricPhysical AllocationEconomic AllocationTime-Based Allocation

Primary Driver

Measurable resource consumption (vCPU-hours, GPU-hours, RAM-GB-hours)

Financial cost of resource usage

Wall-clock time of workload execution

Granularity

High

Medium

Low to Medium

Cloud Provider Data Support

✅ (via detailed usage reports)

✅ (via billing data)

✅ (via timestamps in logs)

Embodied Carbon Factor Source

Hardware Lifecycle Assessment (LCA) databases

Financial cost coupled with industry-average $/kgCO2e ratios

Pro-rata share of hardware LCA over allocated time

Best For

Precise, technical attribution for model training and high-intensity inference

Cost-center reporting and aligning sustainability with FinOps

Long-running, steady-state inference workloads or batch jobs

Key Limitation

Requires detailed telemetry; may not capture idle resource overhead

Assumes cost correlates directly with physical impact, which can be distorted by discounts

Does not account for intensity of resource use during the time period

Calculation Example

(GPU-hours used) * (kgCO2e per GPU-hour from LCA)

(Total workload cost) * (Industry avg. kgCO2e per $ of IT hardware)

(Workload duration / Total hardware lifespan) * (Total embodied carbon of hardware)

Recommended Tool Integration

Integrate with cloud provider's Carbon Footprint Tool + Boavizta API

Use cloud billing exports with tools like Cloud Carbon Footprint

Custom script using workload timestamps and hardware LCA data

TROUBLESHOOTING

Common Mistakes

Calculating the full carbon footprint of AI workloads is complex. These are the most frequent errors teams make when accounting for Scope 2 and 3 emissions, leading to inaccurate reporting and missed reduction opportunities.

Location-based and market-based are the two standard methods for calculating Scope 2 emissions from purchased electricity, and using the wrong one invalidates your report.

  • Location-based method: Uses the average carbon intensity (gCO₂e/kWh) of the local grid where your data center operates. This reflects the physical reality of the electricity consumed.
  • Market-based method: Uses the carbon intensity of the specific electricity you contract for, such as Renewable Energy Certificates (RECs) or Power Purchase Agreements (PPAs). This reflects your procurement choices.

Common Mistake: Reporting only market-based emissions to claim a low carbon footprint, while ignoring the location-based figure. Best practice is to calculate and disclose both. The GHG Protocol Corporate Standard requires it, and it provides a complete picture of your grid impact versus your procurement strategy.

Prasad Kumkar

About the author

Prasad Kumkar

CEO & MD, Inference Systems

Prasad Kumkar is the CEO & MD of Inference Systems and writes about AI systems architecture, LLM infrastructure, model serving, evaluation, and production deployment. Over 5+ years, he has worked across computer vision models, L5 autonomous vehicle systems, and LLM research, with a focus on taking complex AI ideas into real-world engineering systems.

His work and writing cover AI systems, large language models, AI agents, multimodal systems, autonomous systems, inference optimization, RAG, evaluation, and production AI engineering.