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bdavy-scope3 merged 3 commits into from
Sep 25, 2025
Merged

Update methodology documentation to reflect gmsf 1.2 framework alignment #276

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1b74add
Updating device, data transfer and creative defaults
bdavy-scope3 Sep 23, 2025
b34b1c8
Tech Manipulation documentation and other updates
bdavy-scope3 Sep 24, 2025
abda862
default creative storage snippet and wording
bdavy-scope3 Sep 24, 2025
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43 changes: 36 additions & 7 deletions docs/calculations.mdx
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Expand Up @@ -176,7 +176,8 @@ Native product carousel

### Conventional model data transfer by network type

From [SRIxAD database 2.1](https://github.com/SRISyndicatRegiesInternet/SRIxAD-DigitalCampaignsCarbonFramework/releases/download/v2.1.0/Referentiel.SRI.x.AD.-.V2.1_partage.zip), original source ADEME_220830_v1.4
The Scope3 values below are from [GMSF 1.2](https://adnetzero.com/wp-content/uploads/2025/06/GlobalMediaSustainabilityFrameworkV1.2.pdf).
SRI values from [SRIxAD database 2.1](https://github.com/SRISyndicatRegiesInternet/SRIxAD-DigitalCampaignsCarbonFramework/releases/download/v2.1.0/Referentiel.SRI.x.AD.-.V2.1_partage.zip), original source ADEME_220830_v1.4 (now considered outdated).

<ConventionalModelDefaults />

Expand All @@ -188,13 +189,13 @@ From [Carbon impact of video streaming (Carbon Trust)](https://ctprodstorageacco

### Mobile to fixed ratios by country

From [ITU Data Hub](https://datahub.itu.int/) (2022 data)
From [ITU Data Hub](https://datahub.itu.int/) (2024 data), these ratios do not apply to TV and Smart Speakers for which a specific `default_percent_mobile_by_device_type` is set.

<NetworkTrafficDefaults />

### Video player characteristics

Based on actual data transfer of https://vjs.zencdn.net/8.10.0/video.min.js on February 23, 2024
Default video player size from [GMSF 1.2](https://adnetzero.com/wp-content/uploads/2025/06/GlobalMediaSustainabilityFrameworkV1.2.pdf)

<VideoPlayerDefaults />

Expand All @@ -206,7 +207,9 @@ Based on [YouTube recommendations](https://support.google.com/youtube/answer/172

### Device size

From common devices (Quad HD 27” monitor, iPhone 13, Nexus 5X, iPad Air 1/2, iPad 2/3, Nexus 9, 1080P TV)
From common devices (Quad HD 27” monitor, iPhone 13, Nexus 5X, iPad Air 1/2, iPad 2/3, Nexus 9, 1080P TV).

**Note**: We use the software resolution, not the hardware resolution, to avoid underestimating the actual visual coverage of the ad displayed on screen.

<DeviceSizeDefaults />

Expand All @@ -218,18 +221,20 @@ See [Consumer Devices](./consumer_devices)

### Time in view for non-video ads

Observations from various channels
Default in view time from [GMSF 1.2](https://adnetzero.com/wp-content/uploads/2025/06/GlobalMediaSustainabilityFrameworkV1.2.pdf)

<TimeInViewDefaults />

### Ad platform defaults

Observations from various channels
Observations from various channels and CDN / Edge Node emission factors from [GMSF 1.2](https://adnetzero.com/wp-content/uploads/2025/06/GlobalMediaSustainabilityFrameworkV1.2.pdf)

<AdPlatformDefaults />

### Channel and device type mappings

The default ad formats for the Web and App channels are based on the [GMSF 1.2](https://adnetzero.com/wp-content/uploads/2025/06/GlobalMediaSustainabilityFrameworkV1.2.pdf) defaults for creative payload.

<ChannelMappingDefaults />

### Broadcasting defaults
Expand All @@ -238,6 +243,8 @@ Observations from various channels

### Creative storage defaults

Emission factors from [GMSF 1.2](https://adnetzero.com/wp-content/uploads/2025/06/GlobalMediaSustainabilityFrameworkV1.2.pdf), along with assumptions on average distribution per storage type, default multipliers to estimate the required storage space based on the delivered creative size and default impressions per creative.

<CreativeStorageDefaults />

## Lookups from external sources
Expand Down Expand Up @@ -327,6 +334,19 @@ we fall back to a default channel by device.

## Calculating Emissions

### Tech Manipulation - Creative Storage

```
creative_storage_gco2_per_imp =
(default_linear_tape_open_storage_kgco2e_per_gb * default_linear_tape_open_storage_usage_pct
+ default_hard_disk_drive_storage_kgco2e_per_gb * default_hard_disk_drive_storage_usage_pct
+ default_solid_state_drive_storage_kgco2e_per_gb * default_solid_state_drive_storage_kgco2e_per_gb
+ default_cloud_storage_kgco2e_per_gb * default_cloud_storage_usage_pct)
* 1000
* ((creative_data_transfer_bytes * creative_raw_asset_size_factor[Channel] + creative_data_transfer_bytes * creative_work_iterations_factor[Channel]) / 1000000000)
/ default_impressions_per_creative
```

### Creative Delivery - Data Transfer

```
Expand Down Expand Up @@ -431,7 +451,16 @@ creative_platforms = creative_ad_platforms ?? default_creative_platforms

creative_platform_emissions_gco2_per_imp = 0
for platform in [creative_platforms, ad_format.ad_platforms]:
creative_platform_emissions_gco2_per_imp += platform.emissions_per_creative_request_per_geo_gco2_per_imp
emissions_per_creative_request_per_geo_gco2_per_imp =
platform.emissions_per_creative_request_per_geo_gco2_per_imp ??
((creative_data_transfer_bytes / 1000) x
(edge_node_use_watts_per_kb / 1000) x
lookup_carbon_intensity_gco2e_per_kwh(country, region, utc_datetime))
+
(creative_data_transfer_bytes / 1000 x
edge_node_embodied_gco2e_per_kb)

creative_platform_emissions_gco2_per_imp += emissions_per_creative_request_per_geo_gco2_per_imp
```

### Creative Delivery - Consumer Device
Expand Down
11 changes: 2 additions & 9 deletions docs/channel_considerations.mdx
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Expand Up @@ -137,18 +137,11 @@ Similarly to how we model consumer devices (see [Consumer Devices](./consumer_de

### TV Viewing Emissions

We follow the same methodology as described in [Consumer Devices](./consumer_devices), accounting for both use phase (energy consumption) and embodied emission (production & disposal).

We adapt the "synthetic TV system" for Linear TV accordingly:

- Set-top boxes (STBs) and decoders are excluded, as they are already accounted for under household equipment.
- We retain the assumption from Urban et al. that 7% of televisions come with a sound bar.

This results in the following TV system:
We follow the same methodology as described in [Consumer Devices](./consumer_devices), accounting for both use phase (energy consumption) and embodied emission (production & disposal), aligned with GMSF 1.2:

| Device | Power (W) | PEPS (gCO2e/s) |
| --------------------- | --------- | -------------- |
| TV System (Linear TV) | 75 | 0.0096 |
| TV System (Linear TV) | 136.8 | 0.00865 |

### Estimating the number of TV impressions

Expand Down
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