Emission factors in Brazil: MCTI, IPCC and Defra compared

What emission factors are

An emission factor is a coefficient that converts a unit of activity, litres of diesel burned, MWh of electricity consumed, tonnes of waste landfilled, into a quantity of greenhouse gases expressed in tonnes of CO₂ equivalent (tCO₂e).

Without emission factors, a GHG inventory would be nothing but a record of physical consumption. The factor is what turns operational data into a carbon footprint. The accuracy of the inventory depends directly on the quality and the fit of the factors used.

Each emission factor is specific to a combination of activity, fuel, technology, region and period. Using a generic global factor when a specific national or sector factor exists introduces distortions, in either direction, that undermine the usefulness of the inventory.

If you are still mapping where the company's emissions come from, start with the overview of emission sources and sectors. This guide covers the next step: choosing the right factor for each source.

The formula: activity data × emission factor

Every GHG Inventory calculation follows the same sum:

Emissions (tCO₂e) = activity data × emission factor

Activity data is what the company measures: litres of diesel, kWh of energy, tonnes of waste, kilometres flown. The factor says how much gas each unit of that activity emits.

An example, with illustrative values (do not use these numbers in your inventory):

Many databases give the factor split by gas (CO₂, CH₄ and N₂O). In that case, calculate each gas and convert it to CO₂ equivalent using the GWP. With the AR5 GWP, 1 tonne of CH₄ is worth 28 tCO₂e. The sum of the gases gives the total.

Three checks before multiplying: does the unit of the data match the unit of the factor (litre with litre, kWh with kWh)? Is the factor from the same year as the data? Is the factor from the country or grid where the activity took place?

The electricity emission factor in Brazil (SIN)

The emission factor of the Sistema Interligado Nacional (SIN), Brazil's interconnected grid, is probably the most consulted factor in the country. It represents the carbon intensity of the electricity generated on the national grid and is published by MCTI, on the emission factors page of SIRENE.

MCTI publishes more than one type of factor for the SIN. For a corporate GHG Inventory, what matters is the average factor, which MCTI itself indicates for corporate inventories, with monthly values and an annual average. The margin factors (operating margin and build margin) exist for emission reduction projects, such as those under the former CDM. They are not meant for calculating Scope 2.

The value moves with the generation mix: in years of good hydrology, with a high share of hydro, the factor falls. In dry years, with gas and coal thermal plants dispatched, it rises. The expansion of wind and solar also pushes the factor down over time. That is why one year's factor does not hold for another, and copying the number from the previous cycle's spreadsheet is a common mistake.

How to apply it in practice:

• If you have consumption month by month, multiply each month by that month's factor.
• If you only have the annual total, use the annual average for the same year and record that choice.
• Always note the reference year and the date you consulted the MCTI file.

We deliberately do not reproduce the factor's value here: it changes every year and the official source is the MCTI file.

Location-based vs market-based in Scope 2

The GHG Protocol, in its Scope 2 Guidance, asks companies to calculate Scope 2 under two approaches and report both.

Location-based. Uses the average factor of the grid where the energy was consumed. In Brazil, that is the average SIN factor published by MCTI. It reflects the country's physical mix, regardless of the purchase contract.

Market-based. Uses the factor tied to the contractual instruments the company bought: renewable energy certificates such as I-RECs, or free-market contracts that transfer the energy attribute in a traceable way. The instrument must meet the Scope 2 Guidance quality criteria: be exclusive, be retired on the company's behalf, come from the same market and match the period of consumption.

Without an instrument, market-based needs another factor. The standard suggests a residual mix, but Brazil has no official residual mix. In practice, energy without an instrument usually goes into market-based at the average SIN factor, with the limitation disclosed in the report.

Companies on the free market that buy I-RECs can report a much lower market-based Scope 2. Location-based stays the same, because the physical grid has not changed. The two figures appear side by side.

MCTI vs IPCC vs Defra: when to use each

Three emission factor databases are widely used in Brazil: MCTI, IPCC and Defra (the UK Department for Environment, Food and Rural Affairs).

MCTI, Brazil's Ministry of Science, Technology and Innovation. It publishes the SIN factors and the national emissions inventory, available in SIRENE, with Brazilian parameters for energy, waste, agriculture and livestock, land use and industrial processes. That data feeds the calculation tool of the Brazilian GHG Protocol Programme. National parameters reflect local conditions, fuel composition, technologies in use, climate and soil, and tend to fit operations in Brazil better than global factors.

IPCC, Intergovernmental Panel on Climate Change. It publishes default factors in its assessment reports and in the guidelines for national inventories (2006 Guidelines, 2019 Refinement). These are global average factors, useful when no national factor exists or when international comparability is needed. The IPCC also publishes the GWPs (Global Warming Potentials) used to convert different gases into CO2 equivalent.

Defra, UK Department for Environment, Food and Rural Affairs. It publishes a comprehensive UK factor database annually, with broad coverage of Scope 3 categories (air travel, accommodation, materials, logistics). It is often used to fill gaps where neither MCTI nor IPCC offers a factor for a specific category.

The general rule: use MCTI whenever it is available. Fill gaps with IPCC for categories with no national coverage. Use Defra for Scope 3 categories the other two do not cover, particularly travel and materials.

National vs international factor: when to use each

Use a national factor (MCTI, the Brazilian GHG Protocol Programme tool) when the activity takes place in Brazil and a Brazilian factor exists for it. That is the case for SIN electricity and for fuels sold in the country, which have their own blend.

Use an international factor (IPCC, Defra, EPA) in three situations:

• There is no national factor for the activity, such as hotel stays or some purchased materials.
• The activity took place outside Brazil. Energy consumed at a subsidiary in Chile uses the Chilean grid factor, not the SIN one.
• The group reports on a consolidated basis and needs the same database across several countries. Even then, electricity follows the local grid factor.

The EPA, the United States environmental agency, publishes factors designed for the American context. Use them with the same care as Defra: only where a Brazilian factor is missing, and knowing that the power mix and the vehicle fleet are different.

How to document the choice of factor

For each line of the inventory, record:

1. Source and document: database name, version or year of publication, and link.
2. Reference year of the factor, which must match the year of the activity data.
3. Unit of the factor and of the data (for example, kg CO₂e per litre).
4. Gases and GWP: which gases the factor covers and which GWP version was used.
5. Justification, whenever you use an international factor for an activity in Brazil.

That table of assumptions is the first thing independent verification asks for. The full step-by-step of the inventory is in the guide to building a greenhouse gas inventory.

Which factor source to use

A summary by emission type, for operations in Brazil:

Fuels: where to find factors and the care needed with the blend

For fuels used in Brazil, the starting point is the calculation tool of the Brazilian GHG Protocol Programme, maintained by FGVces. It carries factors for the fuels sold in the country and applies each year's blend percentage. When a fuel is missing, the reference is the 2006 IPCC Guidelines (energy volume) and the 2019 Refinement, which provide default factors by fuel type. The national inventory published by MCTI in SIRENE helps to check Brazilian parameters.

The specific care in Brazil is the mandatory blend:

• Diesel B is fossil diesel blended with biodiesel.
• Gasoline C is gasoline blended with anhydrous ethanol.
• Hydrous ethanol is entirely renewable.

The blend percentage is set by the government and changes over the years. Use the blend in force in the period of consumption, not today's.

The renewable portion produces biogenic CO₂. Under the GHG Protocol, that biogenic CO₂ is reported separately, outside the scopes. The CH₄ and N₂O from burning the biofuel go into Scope 1 as normal. Two mistakes come up often: applying the pure diesel factor to the whole volume, which overstates fossil CO₂, and simply discarding the renewable portion without reporting the biogenic CO₂.

Sector-specific factors (transport, energy, waste)

Transport. Transport emission factors depend on vehicle type, fuel, load and distance. With consumption data (litres), apply the fuel factor and the blend rule from the previous section. Without consumption, you can estimate from distance travelled and vehicle type, with greater uncertainty.

For air travel, ICAO and Defra publish factors by cabin class (economy, business, first) and route type (domestic, short-haul, long-haul). The difference is significant: a business class seat can carry a factor 2.5 to 3 times higher than economy, because of the space it occupies.

Electricity. Beyond the SIN factor, companies operating outside the interconnected grid (isolated systems in the Amazon, for example) use isolated-system factors, which tend to be much higher because they depend on diesel generation.

Companies with their own generation, solar PV, small hydro, biomass, can use technology-specific factors. Solar and wind have a zero operational factor (no combustion), but there are life-cycle emissions in manufacturing the panels and turbines.

Waste. Emission factors for solid waste in landfill depend on waste composition (organic fraction), landfill depth, whether methane is captured, and climate. MCTI and the IPCC publish first-order decay (FOD) methodologies to estimate methane emissions over time. Landfills that capture and flare biogas have much lower effective factors.

IPCC AR5 vs AR6: the difference in GWPs

GWPs (Global Warming Potentials) are the coefficients that convert different greenhouse gases into CO2 equivalent. A GWP of 28 for methane (CH4) over a 100-year horizon means one tonne of CH4 has the same climate impact as 28 tonnes of CO2 over a century.

The catch: GWPs change with each IPCC assessment cycle. AR5 (2013) set the 100-year GWP of CH4 at 28 and of N2O at 265. AR6 (2021) adjusted CH4 to 27.9 (essentially stable) but changed how climate feedbacks are accounted for, producing shifts in other gases.

For companies, the move from AR5 to AR6 can shift inventory figures even with no real change in physical emissions. CDP and SBTi already accept both, but consistency within a time series is essential: do not compare a 2023 inventory (calculated on AR5) directly with a 2024 one (calculated on AR6) without an adjustment.

The regulatory direction is a progressive move to AR6. The European CSRD and the ISSB already recommend it. In Brazil, the Brazilian GHG Protocol Programme still accepts AR5, but convergence is a matter of time.

Which GWP to use in the inventory

For N₂O, the 100-year GWP went from 265 in AR5 to 273 in AR6. The difference is small, but it shows up for companies with a lot of nitrogen fertiliser or effluent.

The conservative rule has three parts:

1. Follow the programme you report to. If the inventory goes to the Public Emissions Registry of the Brazilian GHG Protocol Programme, use the GWPs of that cycle's tool version. If it goes to another programme, follow what that programme asks for.
2. Use a single version across the whole inventory. Mixing factors calculated with AR5 and AR6 in the same year distorts the total.
3. Switch with a recalculation. When you change version, recalculate the base year and the years in the series, and record the change in the methodology note.

It is worth remembering that national inventories reported under the Paris Agreement use AR5. That does not bind the company, but it explains why part of the Brazilian databases is still on AR5.

Common mistakes with emission factors

These are the mistakes that come up most when we review spreadsheet inventories:

• Another country's factor. Using the UK or US grid factor for energy consumed in Brazil. The Brazilian power mix is very different, and the result comes out distorted.
• Wrong year. Applying one year's SIN factor to another year's consumption. Because the factor swings with hydrology, the difference can be large.
• Wrong unit. A factor in kg applied as if it were tonnes, MWh confused with kWh, litre confused with cubic metre. A thousand-fold error goes unnoticed if nobody checks the order of magnitude.
• Mixing approaches in Scope 2. Adding location-based to market-based, or using I-RECs to reduce the location-based figure. They are two separate calculations, reported side by side.
• Ignoring the fuel blend. Treating diesel B as pure diesel, or forgetting the biogenic CO₂.
• Inconsistent GWP. Factors from different databases, each with its own GWP version, added up without adjustment.
• Unrecorded source. The number may even be right, but without source and version, independent verification cannot confirm it.

How the Mangue Tech platform manages 60,000+ factors

Managing emission factors is one of the biggest operational challenges in an inventory. The Mangue Tech platform maintains a consolidated database of more than 60,000 emission factors, covering MCTI, IPCC (AR5 and AR6), Defra, Ecoinvent and specific sector sources.

The system offers full traceability: each factor is linked to its source, year of publication, GWP version used and region of application. When MCTI or the IPCC publish updates, the factors are folded into the database and inventories can be recalculated automatically.

For the user, the process is transparent. When you enter activity data, litres of diesel, MWh consumed, tonnes of waste, the system automatically suggests the most appropriate factor, prioritising national sources over global ones and more recent data over older.

That automation removes one of the most common errors in manual inventories: using factors that are out of date, from the wrong region, or with inconsistent GWPs. The result is an inventory that is more accurate, more defensible and easier to audit.

For companies that want the calculation and the documentation done end to end, the Mangue Tech GHG Inventory service delivers the inventory ready for independent verification, with the table of assumptions for every factor.