> For the complete documentation index, see [llms.txt](https://docs.onelens.cloud/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.onelens.cloud/integrations/sustainability/sustainability-for-azure.md). # Sustainability for Azure ## Overview Azure publishes your estimated carbon emissions through carbon optimization. To show them in OneLens, assign one built-in role, **Carbon Optimization Reader**, to the OneLens application on each subscription you want reported. The role grants one thing and nothing else: reading carbon emission reports. It does not allow changes to any resource, and it does not expose service metrics or configuration. {% hint style="warning" %} ## Assign at subscription scope Emissions permissions in Azure are honoured at **subscription** level only. A role assigned at a management group, resource group or individual resource does not grant access to emissions data, so the assignment has to be repeated for each subscription you want included. {% endhint %} ## Step 1: Assign Carbon Optimization Reader You need **Owner** or **Contributor** on the subscription to make this assignment. {% stepper %} {% step %} **Open the subscription** Sign in to the [Azure portal](https://portal.azure.com/), go to **Subscriptions**, and select the subscription you want to report on. {% endstep %} {% step %} **Open Access control** In the left menu, select **Access control (IAM)**. {% endstep %} {% step %} **Add the role assignment** Select **+ Add** > **Add role assignment**. In the **Role** list, search for **Carbon Optimization Reader** and select it. {% endstep %} {% step %} **Select the OneLens application** On the **Members** tab, choose **User, group, or service principal**, select **Select members**, and search for the OneLens app registration you created during onboarding. It is named `onelens-sa` unless you chose a different name. {% endstep %} {% step %} **Review and assign** Select **Review + assign** to complete the assignment, then repeat for every other subscription you want included. {% endstep %} {% endstepper %} If you prefer the CLI, the same assignment is: ```bash az role assignment create \ --assignee \ --role "Carbon Optimization Reader" \ --scope /subscriptions/ ``` ## Step 2: Allow for first-time registration {% hint style="info" %} If nobody in your tenant has opened carbon optimization before, Microsoft registers your tenant on first use. This takes 30 minutes to an hour, during which the page can appear blank or show a registration message. Once registration completes it applies to everyone in the tenant and does not recur. {% endhint %} ## Step 3: Confirm the assignment From the Azure CLI: ```bash az role assignment list \ --assignee \ --scope /subscriptions/ \ --include-inherited \ --output table ``` **Carbon Optimization Reader** should appear in the list for each subscription you configured. ## What to send back to OneLens No new credentials or IDs are needed. OneLens already has your tenant, application and subscription details from the original integration. Tell us only **which subscriptions you assigned the role on**, if it is not all of the ones you onboarded. Azure reports access per subscription, so any subscription without the role is reported back to us as denied, and we would otherwise have to ask whether that was deliberate. ## What you get in OneLens | | Detail | | ------------ | --------------------------------------------------------------- | | Granularity | Monthly | | History | The last 12 months | | Scopes | Scope 1, scope 2 and scope 3 | | Breakdown by | Subscription, resource group, resource, resource type, location | | Published | By the 19th of the following month | Azure is the only one of the three major clouds that attributes emissions down to an **individual resource**, so an Azure estate supports a highest-emitting-resources view that AWS and Google Cloud cannot. ## Good to know * **Azure keeps a rolling 12-month window.** Carbon optimization does not serve data older than the last twelve months, so a multi-year baseline cannot be built from this source. OneLens retains what it has collected, so history accumulates from the point you connect onwards. * **Scope 2 figures may appear as zero.** Carbon optimization shows scope 2 on a market-based basis. Where a region's energy is fully covered by Microsoft's renewable purchases, the market-based figure is legitimately zero, and is not a reporting failure. * **Subscriptions with no usage return nothing**, as do subscriptions created less than a month ago, since at least one published month of usage is required. * **Carbon Optimization Reader covers emissions, not recommendations.** Emission reduction recommendations are surfaced through the subscription **Reader** role that OneLens already holds from cost onboarding, so both are available once this role is added. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. 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