Carbon footprint of mid-size AI models per query and per token

    Factor version soma-ai-ef-2026.10-dataset-v3.0.0. Last updated . Location-based grid averages, not renewable contracts. Estimates from published benchmarks.

    Part of the SOMA AI Emission Factors cluster.

    How much CO₂ does one query to a mid-size model emit?

    One query of 1210 tokens to a mid-size model (class B, such as gpt-4o, chatgpt-4o-latest, gpt-4.1) emits about 0.053 g CO₂e on the global-average grid, and a million tokens emit 0.0388 kg CO₂e. Served from EU North - Sweden the same query emits 0.0094 g, and from Asia Pacific - Singapore 0.055 g.

    For comparison on the same grid, a class A (small) query emits 0.016 g and a class C (frontier) query emits 0.2 g. Class B uses 0.07128907393577297 kWh of facility electricity per million tokens, and its uncertainty band around the class factor is about 39%.

    Class B factors by cloud region

    Per million tokens unless stated. Hardware 0.00101 kg, construction 0.00046 kg and training 0.00293 kg are the same in every region and are included in the total. Per query = 1210 tokens.
    RegionElectricity kgTotal kg CO₂eg per queryWater LmL per query
    Asia Pacific - Japan0.035120.0400.0540.2130.29
    Asia Pacific - Singapore0.035710.0400.055not availablenot available
    EU Central - Germany0.025920.0300.0410.1440.2
    EU North - Finland0.005800.0100.0140.3240.45
    EU North - Sweden0.002740.0070.00940.4300.59
    EU South - Spain0.012100.0160.022not availablenot available
    EU West - Belgium0.009600.0140.0190.1880.26
    EU West - France0.003800.0080.0110.2640.36
    EU West - Ireland0.020140.0250.0330.1060.15
    EU West - UK (London)0.016800.0210.0290.1730.24
    EU-27 average0.016820.0210.029not availablenot available
    Global average0.034450.0390.053not availablenot available
    Netherlands0.019120.0240.0320.2470.34
    US Central - Iowa0.033650.0380.0520.2270.31
    US East - N. Virginia0.021660.0260.0360.1720.24
    US South - Southeast0.030730.0350.0480.1700.24
    US South Central - Texas0.026750.0310.0430.1060.15
    US West - Oregon0.023070.0270.0380.6820.94

    Which region is best for mid-size models?

    EU North - Sweden gives the lowest total for class B, 0.00714 kg CO₂e per million tokens and Asia Pacific - Singapore the highest at 0.0401 kg, a 5.6 times spread. The spread on electricity alone is 13 times.

    How much water does a mid-size model use per query?

    A 1210-token query to a class B model consumes 0.15 mL of water in US South Central - Texas, the lowest-water region with a figure, and 0.94 mL in US West - Oregon, the highest. 14 of 18 regions have a water figure.

    How is a class B total split between its four terms?

    On the global-average grid, electricity is 88.7% of the class B total, hardware 2.6%, data-centre construction 1.2% and amortised training 7.6%. In EU North - Sweden electricity falls to 38.4% and in Asia Pacific - Singapore it rises to 89%. The conservative high case adds 59% to the class total.

    Which models are class B?

    The dataset's mapping table assigns 53 model name patterns from 13 providers to class B, and a star stands for any text. 2 of the 36 mapping rows for this class are flagged as reasoning models by default.

    • Google gemini-*-pro, gemma-*-27b, gemini-1.0-pro, gemini-1.5-pro, gemini-pro, gemini-omni, gemma-*-31b, gemma-
    • Meta llama-3.1-70b, llama-3.3-70b, llama-4-scout, llama3-70b, llama3-1-70b, llama3-3-70b, llama-3-70b, llama4-scout
    • Mistral mistral-small, mistral-medium, mixtral-8x22b, mistral-small-4, codestral, devstral, magistral, mixtral-8x
    • Alibaba qwen*-plus, qwen3-32b, qwen*-122b-a10b, qwen*-27b, qwen*-32b
    • Anthropic claude-sonnet-*, claude-3-sonnet*, claude-3-5-sonnet*, claude-3-7-sonnet*, claude-*-sonnet
    • OpenAI gpt-4o, chatgpt-4o-latest, gpt-4.1, gpt-oss-120b
    • Amazon nova-pro, nova-*-pro, titan-text-express
    • Cohere command-r, aya-expanse-32b, aya-23-35b
    • AI21 jamba-mini, jamba-1.5-mini
    • DeepSeek deepseek-r1-distill-llama-70b, deepseek-r1-distill-qwen-32b
    • NVIDIA nemotron-*-super, nemotron-super
    • Perplexity sonar, sonar-pro
    • Tencent hunyuan-a13b

    Where do these numbers come from and how do I cite them?

    Figures per query are one plain exchange, before the Tier 2b reasoning uplift. Electricity term. GPU energy per token from the ML.ENERGY Leaderboard v3, a facility overhead of 1.20, and grid carbon intensity from EPA eGRID 2023 and Ember 2023. Embodied hardware, data-centre construction and amortised training terms are documented on the methodology page. Water combines on-site cooling water (Li et al. 2025) with the water embedded in grid electricity (Reig et al. 2020). The modelled range of the models inside a class, around the class value, is −41% to +48% for class A, −39% to +24% for class B and −67% to +55% for class C.

    Dataset: AI Inference Emission and Resource Factors for Corporate GHG Inventories (SOMA AI Emission Factors (SAEF)), Llopis-Garcia, G., SOMA AI, 19 October 2026, CC BY 4.0, concept DOI 10.5281/zenodo.20443585, which resolves to the latest version (this version 10.5281/zenodo.23371447, earlier version 2 values at 10.5281/zenodo.22767475). Method: Accounting for Purchased AI Inference in Corporate GHG Inventories: A Token-Based Method, arXiv:2606.10660, under peer review.

    Partners can fetch any row from the AI factors API, and the whole table is a CSV download.

    The full table for every class and region is on the SOMA AI Emission Factors (SAEF) page.

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