Technology Carbon Standard Schema

The Technology Carbon Standard is a structured framework for measuring and managing the carbon emissions of an organisation’s technology estate. This schema provides organisations with a consistent way to report on their technology-related carbon emissions across their complete ICT landscape.

Purpose

The TCS Schema serves a critical purpose in the sustainability landscape:

• Standardised Reporting: It creates a uniform machine-readable format for technology-related carbon emissions, enabling consistent reporting across organisations.
• Discoverability - Details TBC: Organisations publish their TCS emissions data in a standardised file named tcs.json either at the root domain; https://example.com/tcs.json or, preferably at the “well-known location” of their web domain e.g., https://example.com/.well-known/tcs.json, making it easily discoverable. Note: well-known location requires approved registration, TBC….
• Accessibility: This standard location and format makes emissions data directly accessible to automated systems, reporting tools, industry benchmarks, and other machine-readable services without requiring manual data extraction.
• Transparency: By making emissions data available in a structured, public format, organisations demonstrate their commitment to transparency and environmental responsibility.
• Comparability: The standardised format allows for meaningful comparison of emissions data across different organisations and time periods.

By implementing the Technology Carbon Standard, your organisation contributes to a more transparent technology sector where carbon emissions can be systematically tracked, compared, and ultimately reduced.

Schema Version

Current version: 0.0.1

The Technology Carbon Standard schema follows semantic versioning (MAJOR.MINOR.PATCH) and is hosted in a version-specific manner:

• Canonical URL: https://techcarbonstandard.org/schemas/techcarbonstandard_schema/v0.0.1.json
• Latest Version: https://techcarbonstandard.org/schemas/techcarbonstandard_schema/latest.json

Organisations implementing the standard should reference the specific version they are using in their implementation while developers and tools can use the “latest” URL to stay current with updates.

Overview

The Technology Carbon Standard emissions file consists of:

• the reporting organisation (required)
• the reporting period (required)
• the verification method (required)
• any related disclosures
• the emissions reported across the TCS categories

The categories of emissions into four main categories:

1. Upstream Emissions: Embodied carbon in hardware and carbon impact of software development
2. Direct Emissions: Running costs from electricity powering servers, networks, and devices
3. Indirect Emissions: Running costs attributed to external hardware and service solutions
4. Downstream Emissions: Carbon emissions associated with the use of products and services by end users

The *tcs.json emissions file is an array of emissions reports. Each TCS report (by reporting period, or organisation entity), can be added to the array of reports.

Schema Structure

The schema requires each TCS emission report object be listed in an array.

// tcs.json
[
	// TCS Report for reporting period 2024-2025:
	{
		"organisation": {...},
		"reporting_period": {...},
		"verification": {...},
		"disclosures": {...},
		"upstream_emissions": {...},
		"direct_emissions": {...},
		"indirect_emissions": {...},
		"downstream_emissions": {...}
	},

	// TCS Report for reporting period 2023-2024:
	{
		"organisation": {...},
		"reporting_period": {...},
		"verification": {...},
		"disclosures": {...},
		"upstream_emissions": {...},
		"direct_emissions": {...},
		"indirect_emissions": {...},
		"downstream_emissions": {...}
	}
]

Organisation Information (required)

Basic details about the reporting organisation, for example:

"organisation": {
  "name": "Example Corp",
  "description": "Description of the organisation",
  "open_corporates_id": "12345678",
  "registered_country": "England",
}

Verification and Auditing (required)

The schema includes fields for verification status and auditor information. The verification field indicates the level of assurance for the reported emissions data:

"verification": "independently verified",
"auditor_link": "https://example-auditor.com/"

Conditional Requirement: When verification is set to ‘independently verified’, the auditor_link field becomes required. This ensures that claims of independent verification are supported by accessible documentation.

// Example with self-reported data
"verification": "self reported"

// Example with independently verified data
"verification": "independently verified",
"auditor_link": "https://example-auditor.com/"

Reporting Period (required)

The timeframe covered by the emissions report:

"reporting_period": {
  "from_date": "2023-01-01",
  "to_date": "2023-12-31"
}

Disclosures

The disclosures property contains an array of objects that document and link to relevant sustainability and emissions calculation methodology information. For example:

"disclosures": [
  {
    "url": "https://example.com/sustainability",
    "doc_type": "Report",
    "description": "Annual sustainability report"
  },
  {
    "url": "https://example.com/methodology",
    "doc_type": "Methodology",
    "description": "Carbon calculation methodology"
  }
]

Emissions Categories

Each emissions category uses a common structure and is always reported in kgCO2e:

{
  "emissions": 1000,
  "notes": "Notes on the carbon calculation"
}

For GHG Scope 2 emissions (direct operational emission, category O), a further optional field is available for indicating the use of location or market based emissions calculation.

{
	"emissions": 1000,
  "notes": "Notes on the carbon calculation",
	"method": "location-based"
}

1. Upstream Emissions

Emissions related to embodied carbon in hardware and carbon impact of software development:

"upstream_emissions": {
  "software": { "emissions": 0, "notes": "..." },
  "employee_hardware": { "emissions": 55000, "notes": "..." },
  "network_hardware": { "emissions": 1000, "notes": "..." },
  "server_hardware": { "emissions": 0, "notes": "..." }
}

2. Direct Emissions

Emissions from electricity powering the organisation’s technology:

"direct_emissions": {
  "onsite_employee_hardware": { "emissions": 5000, "notes": "...", "method": "location-based" },
  "networking": { "emissions": 1000, "notes": "...", "method": "location-based" },
  "servers": { "emissions": 1000, "notes": "...", "method": "mixed-methods" },
  "generators": { "emissions": 0, "notes": "..." }
}

Note that the GHG Scope 2 onsite_employee_hardware, networking and servers have an additional, optional field for recording the calculation method; method.

3. Indirect Emissions

Emissions related to off-site end-user equipment and services:

"indirect_emissions": {
  "offsite_employee_hardware": { "emissions": 3000, "notes": "..." },
  "cloud_services": { "emissions": 5000, "notes": "..." },
  "saas": { "emissions": 84000, "notes": "..." },
  "managed_services": { "emissions": 1000, "notes": "..." }
}

4. Downstream Emissions

Emissions associated with customer use of products and services provided by the reporting organisation:

"downstream_emissions": {
  "end_user_devices": { "emissions": 1000, "notes": "..." },
  "network_data_transfer": { "emissions": 1000, "notes": "..." }
}

Required and Optional Fields

The Technology Carbon Standard schema requires certain fields while making others optional:

Required Fields

• organisation (with required sub-field name)
• reporting_period (with required sub-fields from_date and to_date)
• verification

Conditionally Required Fields

• auditor_link: Required if verification is set to ‘independently verified’

Optional Emissions Categories

Emissions categories are optional, providing flexibility for organisations to report only on categories relevant to their operations. The schema validates that:

• If categories are included, they must follow the correct structure
• All fields within a category must use the appropriate emissions definition format

Example Implementation

Below is an example of a complete Technology Carbon Standard report:

[
	{
		"organisation": {
			"name": "Scott Logic"
		},
		"reporting_period": {
			"from_date": "2023-01-01",
			"to_date": "2023-12-31"
		},
		"verification": "self reported",
		"disclosures": [
			{
				"url": "https://scottlogic.cdn.prismic.io/scottlogic/ZrSd7UaF0TcGIxye_EnvironmentalImpactReport2023.pdf",
				"doc_type": "Report",
				"description": "Scott Logic 2023 Sustainability Report"
			}
		],
		"upstream_emissions": {
			"software": {
				"emissions": 0,
				"notes": "Not currently meaningfully calculable or estimatable"
			},
			"employee_hardware": {
				"emissions": 55000,
				"notes": "Embodied carbon of purchased laptops and monitors, using production and transportation figures from manufacturers' product lifecycle reports"
			},
			"network_hardware": {
				"emissions": 1000,
				"notes": "Loose estimate, based on minimal hardware purchase"
			},
			"server_hardware": {
				"emissions": 0,
				"notes": "No servers or storage hardware purchased"
			}
		},
		"direct_emissions": {
			"onsite_employee_hardware": {
				"emissions": 5000,
				"notes": "Calculated using UK grid carbon intensity 2023; exact laptop and monitor counts; and, average laptop and monitor power consumption figures"
			},
			"networking": {
				"emissions": 1000,
				"notes": "Loose estimate, based on known minimal networking infrastructure"
			},
			"servers": {
				"emissions": 1000,
				"notes": "Loose estimate, based on known minimal infrastructure"
			},
			"generators": {
				"emissions": 0,
				"notes": "No generators"
			}
		},
		"indirect_emissions": {
			"offsite_employee_hardware": {
				"emissions": 3000,
				"notes": "Calculated using UK grid carbon intensity 2023; exact laptop and monitor counts; and, average laptop and monitor power consumption figures"
			},
			"cloud_services": {
				"emissions": 5000,
				"notes": "Full cloud estate measured using Cloud Carbon Footprinting tool"
			},
			"saas": {
				"emissions": 84000,
				"notes": "Spend-based estimate calculated using Plan A platform"
			},
			"managed_services": {
				"emissions": 1000,
				"notes": "Loose estimate, based on known minimal managed services"
			}
		},
		"downstream_emissions": {
			"end_user_devices": {
				"emissions": 1000,
				"notes": "Calculated based on www website traffic figures"
			},
			"network_data_transfer": {
				"emissions": 1000,
				"notes": "Calculated based on emissions estimate associated with www website and its traffic figures"
			}
		}
	}
]

Implementation Guide

1. Gather Emissions Data

Use the Technology Carbon Standard to identify the categories of technology emissions and the recommendations for gathering and calculating these emissions.

Upstream Emissions

Direct Operational Emissions

Indirect Operational Emissions

Downstream Emissions

2. Create a tcs.json File

Create a tcs.json (TBC) file that follows the Technology Carbon Standard Schema and populate the emissions data.

You can validate your tcs.json file against the schema using tools like:

• JSON Schema Validator
• Command-line tools such as ajv-cli

3. Publish the tcs.json File

Publish your tcs.json file at the root of your organisation’s web domain e.g., https://example.com/tcs.json or, preferably at the “well-known location” of their web domain e.g., https://example.com/.well-known/tcs.json and ensure it is publically accessible.

Resources

• Complete JSON Schema
• GitHub Repository

Contributing

We welcome contributions to improve the Technology Carbon Standard. Please submit issues or pull requests to our GitHub repository.