Carbon-Aware LLM Research


Overview

Large Language Models (LLMs) are transforming AI, but their energy use and carbon emissions are substantial and growing. My research in this area develops accurate carbon measurement, prediction, and optimization tools that span model training, inference, and deployment — from cloud GPUs to edge processors. Rather than relying on coarse estimates, these works provide system-aware, phase-aware, and hardware-calibrated frameworks that enable practitioners and researchers to understand and reduce the environmental footprint of LLMs.

Key contributions include:

  • End-to-end carbon modeling that integrates hardware utilization and embodied carbon.
  • Learned predictors that estimate inference carbon with high fidelity across configurations.
  • Estimators for edge LLM deployments that account for peripherals and embodied costs.

LLMCarbon (ICLR 2024) — End-to-end carbon modeling

Goal: Provide an accurate, reusable framework to estimate total carbon emissions of LLMs before training begins.

Approach:

  • Parametric models linking LLM design (model size, architecture, MoE vs dense), execution (batch size, GPU utilization), and embodied hardware cost.
  • Combines operational energy measurements with amortized manufacturing carbon.

Impact:

  • Predicts pre-training carbon with improved accuracy compared to prior tools.
  • Helps designers explore carbon–performance tradeoffs early in model development.

Artifact:
Code and datasets available at the LLMCarbon GitHub repository.


LLMCO₂ (2024–2025) — Learned inference carbon prediction

Goal: Predict the carbon cost of LLM inference across diverse hardware and request patterns.

Approach:

  • Train a machine learning model (graph-based) to capture interactions between request characteristics (prompt length, batch size), model features (quantization, sparsity), and hardware performance patterns.
  • Evaluate on measured inference traces spanning multiple GPU types and workloads.

Impact:

  • Surpasses traditional formula-based estimators in prediction accuracy.
  • Enables carbon-aware scheduling for cloud and service deployments.

Artifact:
Published as a dataset and predictor model in support of inference carbon estimation.


CO2-Meter (AAAI 2026) — Carbon estimation for edge LLMs

Goal: Extend carbon estimation to edge LLM inference, where peripherals and embodied costs are significant.

Approach:

  • Modular estimator separating SoC operational energy, peripherals, and embodied amortization.
  • Models distinct execution phases (prefill, decode) and platform-specific overheads (NPU, GPU, quantized CPU).
  • Validated on a curated dataset of edge inference traces.

Impact:

  • Demonstrates that peripherals and embodied costs materially influence carbon rankings.
  • Provides actionable estimates for edge deployment decisions (e.g., local quantized model vs cloud offload).

Artifact:
Public implementation and data preprocessing scripts released with the paper.


Common Methods Across Works

  • Hardware-aware calibration: Model carbon cost using real utilization and trace data from GPUs and edge SoCs.
  • Phase awareness: Separate modeling for training, inference prefill, and decode phases to capture utilization dynamics.
  • End-to-end accounting: Combine operational and embodied carbon to support realistic lifecycle comparisons.
  • Reproducibility: Publicly available code and datasets for estimation and evaluation.

Practical Insights

  • Inference matters: In many deployment scenarios, inference carbon rivals or exceeds training emissions.
  • Phase and hardware context are critical: Simple FLOPS-based formulas are insufficient for consistent prediction across configurations.
  • Embodied carbon influences decisions: Particularly on edge devices and in long-running deployments, amortized manufacturing impact changes optimal choices.

  • LLMCarbon (ICLR 2024): Model repository and documentation.
  • LLMCO₂: Predictor models and dataset for inference carbon.
  • CO2-Meter (AAAI 2026): Edge estimator code and dataset.