Emission Factors for UAE Climate Reporting: Local Data, IPCC, DEFRA and Supplier Factors

Prepared in British English as a practitioner Knowledge Card Package: answer, explanation, application, evidence, connections and publishing layer.

An inventory can be mathematically correct and still be technically weak. Multiplying the right activity number by a factor for the wrong country, fuel specification, heating-value basis or year can create a material error. The same problem arises when a factor includes upstream emissions but the inventory treats it as direct combustion, or when a refrigerant factor uses one GWP assessment report while the rest of the inventory uses another.

Factor governance therefore has two objectives:

• produce an emissions result that represents the actual source as faithfully as practicable; and

• preserve a complete trail showing why that factor was permitted, selected, converted, reviewed and retained.

Figure 1. Emission-factor hierarchy for UAE MRV. Branded educational visual by London Reporting Academy.

Article 6(1)(a) requires designated Sources to measure emissions regularly, prepare an emissions inventory and submit periodic reports according to standards specified by the Ministry or the competent authority. This makes the applicable authority instruction the first source of truth for factors, methods and GWP values.

The federal law does not, by itself:

• require IPCC factors in every corporate inventory;

• state that UAE-specific factors always exist for every source;

• authorise UK Government factors as a universal substitute;

• prescribe one GWP assessment report for every reporting route;

• establish a permanent ranking between supplier-specific and default factors; or

• remove the need to test units, heating values, boundaries and factor vintage.

A company may use GHG Protocol or ISO 14064-1 as an inventory framework where that is accepted or useful, but those standards do not replace a programme-specific rule. ISO 14064-1 and the GHG Protocol Corporate Standard are programme-neutral: an applicable government programme can add or modify requirements.

The following hierarchy works as a controlled decision sequence. Move down only when the higher level is unavailable, inapplicable or not authorised.

1. Authority-prescribed factor

Use the factor, table, methodology or calculation workbook prescribed in the current official instruction. Record the instrument, version, issue date, effective period and any permitted alternatives.

A factor is not necessarily authority-prescribed merely because it appears in an old template, workshop slide or consultant workbook. Confirm whether the source is current, binding or guidance-only.

2. UAE-, emirate-, utility- or technology-specific factor

Where choice is permitted, local factors usually provide the best geographic and technical fit. Examples include:

• fuel-specific carbon content or net calorific value supplied under a recognised local methodology;

• an emirate or national grid factor for purchased electricity, where the relevant reporting route requires it;

• facility-specific laboratory analysis of fuel or raw material;

• a technology-specific process factor; or

• a utility or district-cooling factor prepared for the relevant period and boundary.

"Local" is not enough on its own. The factor must still match the source, year, unit and method. A UAE grid factor cannot replace a combustion factor. A utility factor for delivered electricity may not be suitable for electricity generated and consumed on-site.

3. Supplier-specific factor

Supplier-specific data can improve accuracy, especially for products, fuels, refrigerants, logistics or purchased energy. It is defensible only when the company can answer:

• What exactly is the factor measuring?

• Does it cover direct emissions, life-cycle emissions or both?

• Which product, site, contract, batch or technology does it represent?

• Which year and geography does it represent?

• What gases and GWP values are included?

• How were shared emissions allocated?

• Was the result independently verified, internally reviewed or neither?

• Are exclusions, uncertainty and recalculation policies documented?

A supplier's corporate Scope 1 and Scope 2 footprint is not automatically a product emission factor. A product carbon footprint is not automatically appropriate for a direct-emissions inventory. Use the figure only for the boundary it actually represents.

4. IPCC or another accepted default

The 2006 IPCC Guidelines and the 2019 Refinement provide internationally recognised default methods and factors. The 2019 Refinement supplements and updates the 2006 Guidelines; it does not replace them wholesale.

IPCC defaults are especially useful where:

• local or technology-specific data are unavailable;

• the authority permits internationally recognised default methods;

• the source is well represented by the default category; and

• the organisation documents the tier, factor source, assumptions and uncertainty.

The detailed Environment Agency - Abu Dhabi technical guidance published in 2025 encouraged country- or technology-specific factors where available and identified the IPCC Emission Factor Database as a fallback where local or technology-specific factors were unavailable. That is useful local implementation evidence, but companies should confirm the current February 2026 v8 guidance and any later legislation before treating the 2025 wording as controlling.

5. DEFRA or another foreign factor

The 2026 UK Government conversion factors state that they enable users to calculate emissions from UK activities. They are suitable for UK-based organisations and international organisations reporting UK operations. The publisher also notes that use for other purposes is at the user's own risk.

A UK factor may still be useful where it represents a genuinely international activity or where no better accepted factor is available, for example a particular travel mode or a screening estimate. Before using it for a UAE source, document:

• why the factor's geography is not distorting the result;

• whether fuel specification, grid mix, vehicle fleet, climate or operating conditions differ;

• whether the factor is direct, well-to-tank, life-cycle or combined;

• whether the authority accepts the method; and

• what improvement action will replace the proxy if the source is material.

A factor is usable only when the activity data and factor denominator match. Common bases include:

• tCO2 per terajoule;

• kg CO2 per litre;

• kg CO2e per kilogram of refrigerant;

• kg CO2e per kWh;

• tCO2 per tonne of product; and

• kg CO2e per passenger-kilometre or tonne-kilometre.

Controls should test mass, volume, energy and distance conversions. Normal cubic metres are not the same as uncorrected metered cubic metres. Litres and tonnes require density where the factor basis differs. Kilowatt-hours and terajoules require a controlled conversion. Carbon factors and CO2 factors differ by the molecular conversion between carbon and carbon dioxide.

A good workbook does not hide conversions inside a single formula. It stores the raw unit, conversion factor, converted unit and final emissions separately so that a reviewer can reproduce each stage.

Combustion factors may be based on net calorific value (NCV), also called lower heating value, or gross calorific value, also called higher heating value. Mixing an NCV-based activity value with a gross-calorific-value factor creates a systematic error.

The detailed EAD 2025 guidance used an NCV-based standard combustion formula: activity in terajoules based on NCV multiplied by an emission factor expressed per terajoule consistently based on NCV, together with the oxidation factor. This is a local example of why the basis must be stated explicitly.

For every energy factor, retain:

• whether the activity data are mass, volume or energy;

• the calorific value source and test period;

• whether the calorific value is net or gross;

• the density, temperature or pressure conversion where relevant; and

• any oxidation or conversion factor.

Global warming potential converts non-CO2 gases to CO2 equivalent over a specified time horizon. The GHG Protocol's August 2024 GWP compilation includes AR4, AR5 and AR6 100-year values and recommends the latest AR6 values, but a regulator or reporting programme may prescribe another set.

The key control is consistency. Record:

• the assessment report and version;

• the time horizon;

• the exact gas or refrigerant;

• treatment of fossil and non-fossil methane where relevant;

• any programme-specific requirement; and

• the trigger for recalculating comparatives after a GWP change.

Do not update one refrigerant calculation to AR6 while leaving the rest of the inventory on AR5 without a documented transition decision.

Figure 2. Controlled emission-factor register. Branded educational visual by London Reporting Academy.

The factor register should be a controlled master, not a list copied into each worksheet. Recommended fields are:

Lock, use and change

A strong process has five gates:

1. Propose. The data owner or methodology lead nominates a factor with the source file.

2. Technical review. A second person checks authority status, boundary, geography, units, year, heating values and GWP.

3. Approve and lock. The factor receives an ID and is frozen for the reporting cycle.

4. Use and reconcile. Workbooks call the factor ID rather than manual numbers.

5. Change control. Any update records the old and new values, reason, affected sources, recalculation assessment and approval.

Never overwrite the old factor entry. Retain superseded factors because the five-year Article 6 record must allow historic emissions to be reproduced.

Illustrative scenario - not company data. A manufacturing facility has metered natural-gas consumption. The inventory team finds three options:

• an old corporate factor from a UK workbook;

• a current IPCC default; and

• a local laboratory-derived NCV and carbon-content result accepted in the facility's monitoring plan.

The team selects the local result because it matches the supplied gas, period, unit basis and approved monitoring plan. The IPCC value is retained as a reasonableness benchmark. The UK factor is rejected for the UAE combustion source because its provenance and fuel basis do not match the local data.

The factor register records the laboratory certificate, sampling period, NCV basis, oxidation factor, formula, approval and the difference from the prior-year factor. Because the change materially affects the emissions trend, the team performs a comparative recalculation assessment rather than describing the reduction as operational performance.