Guides
Practical explanations of greenhouse gas accounting methods and the emission factors behind them. Each guide lists the sources it relies on, and figures come from the official files in our factor library.
GHG accounting basics
Scopes, inventories, boundaries and greenhouse gas units.
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Scope 1, 2 and 3 emissions explained
What the three scopes of the GHG Protocol cover, which gases are included, what is required versus optional, and how a small company's footprint splits across them.
CO2 vs CO2e: global warming potentials (AR4, AR5, AR6) explained
What CO2 equivalent means, how global warming potentials convert methane, nitrous oxide and refrigerants to CO2e, and how AR4, AR5 and AR6 values differ.
GHG base year and recalculation: when to restate past emissions
How to choose a base year, the events that require recalculating it under the GHG Protocol, the significance threshold, and why organic growth does not count.
Organisational boundaries: equity share, financial control and operational control
Which subsidiaries, joint ventures and leased sites belong in your GHG inventory: the three consolidation approaches of the GHG Protocol with a worked example.
How to build a GHG inventory step by step
A practical sequence for a first corporate carbon footprint: boundaries, data collection by scope, factors, quality checks, and what to report.
Standards and frameworks
GHG Protocol standards, ISO 14064 and 14067, ESRS E1, CDP and VSME.
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Carbon accounting standards and frameworks: GHG Protocol, ISO 14064, ESRS and VSME
How the main carbon accounting standards fit together: the GHG Protocol family, ISO 14064-1 and ISO 14067, the EU's ESRS under the CSRD, and the voluntary VSME standard for SMEs.
Targets and SBTi
Science-based targets: near-term, long-term and net-zero, and how they are validated.
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Science-based targets (SBTi) explained: near-term, long-term and net-zero
What the SBTi Corporate Net-Zero Standard requires today (V1.3.1), when Version 2.0 becomes mandatory, the Scope 3 thresholds, and what you need from your inventory first.
Scope 2: electricity and heat
Grid factors, location- and market-based methods, purchased heat.
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Scope 2 emissions from electricity and heat: how to calculate them
A step-by-step method for Scope 2: which data to collect, which grid factor to use in the UK and Italy, how to handle heat and steam, and what to report.
Location-based vs market-based Scope 2: what each method measures
The two Scope 2 methods in the GHG Protocol, when you must report both, what counts as contractual evidence, and what the 2025 revision proposes.
Purchased heat and steam: Scope 2 emissions from district heating
How to report heat, steam and cooling bought from a network: Scope 2 calculation, distribution losses and upstream emissions in Scope 3, with DESNZ 2026 factors.
UK electricity emission factor (DESNZ 2026): what each number covers
The four UK government electricity factors for 2026, generation, grid losses and their upstream emissions, which scope each belongs to, and how they add up per kWh.
Scope 3: the value chain
The 15 categories, spend-based methods, travel, freight and waste.
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The 15 Scope 3 categories explained
All 15 Scope 3 categories of the GHG Protocol in one place: what each covers, upstream versus downstream, which calculation methods apply, and where to start.
Scope 3 category 1: purchased goods and services with spend-based factors
How to estimate category 1 from your accounts with spend-based factors: the four GHG Protocol methods, the U.S. EPA supply chain factors, currency and price-year conversion, and when to move to supplier data.
Scope 3 category 10: processing of sold products
For companies selling intermediate products: what category 10 covers, the site-specific and average-data methods, and what to do when end uses are unknown.
Scope 3 category 11: use of sold products
Why lifetime emissions of products sold this year are reported in the year of sale, direct versus indirect use-phase emissions, and a worked example for an electrical product.
Scope 3 category 12: end-of-life treatment of sold products
How to estimate emissions from the disposal of the products and packaging you sell, using the same waste methods and factors as category 5.
Scope 3 category 13: downstream leased assets
For landlords and lessors: when the energy use of assets you own and lease to others belongs in category 13, and how to estimate it.
Scope 3 category 14: franchises
What franchisors report in category 14, what franchisees report, and the franchise-specific and average-data methods.
Scope 3 category 15: investments
Financed emissions in the GHG Protocol: who category 15 is for, the investment types it covers, and how emissions are allocated by share of equity.
Scope 3 category 2: capital goods
How to account for the emissions from producing equipment, buildings and vehicles you buy: the boundary with category 1, why emissions are not depreciated, and the calculation methods.
Scope 3 category 3: well-to-tank and grid losses explained
What Scope 3 category 3 covers, the four activities in the GHG Protocol guidance, and a worked UK example with gas and electricity using DESNZ 2026 factors.
Freight emissions in Scope 3: tonne-km, categories 4 and 9
How to calculate freight and logistics emissions: when transport is category 4 or 9, the tonne-km formula, mode comparisons from DESNZ 2026, and the data to ask carriers for.
Scope 3 category 5: waste generated in operations
What category 5 includes, the three calculation methods, how recycling is treated, and why landfill dominates: a worked example with DESNZ 2026 waste factors.
Scope 3 category 6: business travel emissions and radiative forcing
How to calculate business travel emissions: what is in category 6, fuel, distance and spend methods, radiative forcing for flights, hotel stays, and a worked example with DESNZ 2026 factors.
Scope 3 category 7: employee commuting and homeworking
How to estimate commuting emissions with a staff survey, the distance-based formula, extrapolating from a sample, and homeworking with DESNZ 2026 factors.
Scope 3 category 8: upstream leased assets
When the buildings, vehicles and equipment you lease belong in Scope 1 and 2 and when they belong in category 8, and how to estimate them.
Scope 3 category 9: downstream transportation and distribution
Transport, storage and retail of your products after sale when you do not pay for it: how category 9 differs from category 4 and how to estimate it.
Scope 1: direct emissions
Fuels burned on site, company vehicles and refrigerant leaks.
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Scope 1 emissions: fuels, vehicles and refrigerants
What counts as Scope 1, the four types of direct emissions, and worked examples for gas boilers, diesel vans, company cars and refrigerant leaks with UK 2026 factors.
Fuel combustion emissions: natural gas, diesel, LPG and heating oil
How to calculate Scope 1 emissions from fuels with DESNZ 2026 factors: choosing the right unit, gross vs net calorific value, biofuel blends, and common errors.
Refrigerant leakage: how to calculate F-gas emissions
Why small refrigerant leaks matter, how to estimate them from service records, and the CO2e factors for common refrigerants such as R410A, R404A, R32 and R134a.
Emission factors
What factors are, where they come from and how to choose them.
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What is an emission factor, and how do you choose the right one?
How emission factors turn activity data into emissions, where official factors come from (DESNZ, ISPRA, EPA, IPCC), and six checks before you use one.
Italy
Italian national data for corporate carbon footprints.
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Corporate carbon footprint in Italy: data, factors and reporting
What an Italian company needs for a GHG inventory: ISPRA electricity and grid-loss factors, guarantees of origin, fuels, and where the EU's CSRD and VSME fit in.
Italian electricity emission factors (ISPRA): production, consumption and grid losses
Which ISPRA factor to use for electricity in Italy, what each one includes, how they have changed since 1990, and a worked example for 100,000 kWh.