A glossary of carbon terms for sustainability Carbon 101

Arbor's Carbon 101 glossary simplifies complex carbon terms, acronyms, and frameworks in the sustainability industry. Covering key carbon and climate terms, this glossary provides you with all the definitions needed to become a carbon expert.

Arbor's Carbon 101 glossary simplifies complex carbon terms, acronyms, and frameworks in the sustainability industry. Covering key carbon and climate terms, this glossary provides you with all the definitions needed to become a carbon expert.
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Avoided Emissions

Avoided emissions refer to the greenhouse gases that are not emitted due to sustainable practices or technologies, which would have otherwise been released in a 'business as usual' scenario.

CO₂ Equivalent (CO₂e)

The universal unit of measurement to indicate the global warming potential (GWP) of each GHG, expressed in terms of the GWP of one unit of carbon dioxide.

Carbon Credit

A carbon credit represents a metric ton of CO2 equivalent that is avoided or sequestered outside the GHG accounting boundary.

Carbon Intensity

The amount of GHG emissions per unit of product or activity. Carbon intensity can be used to compare the environmental impact of different products or processes.

Carbon Neutrality

A state where annual GHG emissions are completely canceled out or removed through offsetting or carbon dioxide removal (CDR) or emissions removal measures.

Carbon Offsetting

A mechanism by which a company can compensate for its greenhouse gas emissions by funding projects that reduce emissions elsewhere, such as renewable energy or reforestation projects.

Circular Economy

An economic system that is based on minimizing waste and maximizing the use of resources by reusing, repairing, and recycling products and materials.

Corporate Emissions

Corporate emissions are greenhouse gases released by company operations, categorized into three scopes by the Greenhouse Gas Protocol: direct, indirect from energy, and other indirect.


Cradle-to-Gate assesses a product’s environmental impact from raw material extraction to when it exits the factory but excludes its use and disposal phases.


Cradle-to-Grave evaluates a product’s full environmental impact from raw material extraction through manufacturing, use, and ultimate disposal.

Embodied Carbon

The total amount of carbon emissions associated with the production of a product or service, including emissions from raw material extraction, processing, manufacturing, transportation and disposal.

Financed Emissions

Financed emissions are greenhouse gases produced indirectly through an organization's investment activities, such as those resulting from loans, investments, and underwriting.

GHG Protocol

A widely used standard developed by the World Resources Institute (WRI) and the World Business Council for Sustainable Development (WBCSD) for measuring and reporting greenhouse gas emissions.

Global Average Carbon Calculation

Global average carbon calculation uses universal emission benchmarks per activity unit, simplifying carbon footprint estimates at the cost of accuracy and regional detail.

Global Warming Potential (GWP)

A factor describing the radiative forcing impact (degree of harm to the atmosphere) of one unit of a given GHG relative to one unit of CO2.

Green Financing

Green financing involves allocating funds to projects and businesses that provide environmental benefits, like renewable energy, to support sustainable economic growth.

Greenhouse Gases (GHG)

GHGs are the seven gases covered by the UNFCCC: carbon dioxide (CO2); methane (CH4); nitrous oxide (N2O); hydrofluorocarbons (HFCs);perfluorocarbons (PFCs); sulphur hexafluoride (SF6); and nitrogen trifluoride (NF3).

Hybrid Carbon Calculation

Hybrid carbon calculation combines spend-based and process data for a more precise and comprehensive emissions profile, balancing scalability and data accuracy.

Life Cycle Assessment (LCA)

A method to assess the environmental impact of a product or service over its entire life cycle, from raw material extraction to end-of-life disposal.

Primary Data

Primary data in carbon measurement is collected directly from a company's specific activities, providing accurate and specific insights for precise carbon footprint assessments.

Product Category Rules (PCR)

A set of rules and requirements that define the methodology for conducting an LCA for a specific product category.

Product Environmental Footprint (PEF)

A methodology developed by the European Commission to measure the environmental impact of products based on LCA, with a focus on carbon and other environmental indicators.

Product Environmental Footprint Category Rules (PEFCR)

A methodology used to assess the environmental footprint of a product or service, which defines the rules and requirements for conducting a Life Cycle Assessment (LCA).

Science Based Targets Initiative (SBTi)

A collaboration between CDP, the United Nations Global Compact (UNGC), the World Resources Institute (WRI), and the World Wildlife Fund (WWF) that helps companies set and achieve ambitious greenhouse gas reduction targets based on climate science.

Scope 1 Emissions

Direct greenhouse gas emissions from sources that are owned or controlled by a company, such as emissions from fuel combustion in company-owned vehicles or boilers.

Scope 2 Emissions

Indirect greenhouse gas emissions from the consumption of purchased electricity, heat, or steam by a company.

Scope 3 Emissions

Indirect greenhouse gas emissions that occur in a company's value chain, including emissions from purchased goods and services, employee commuting, and the use and disposal of sold products.

Secondary Data

Secondary data in carbon measurement is sourced from external datasets and research, enriching carbon assessments with broader industry context when primary data isn't feasible.

Spend-based Carbon Calculation

Spend-based carbon calculation estimates emissions by applying emission factors to financial expenditures on goods and services, often lacking in specificity.

Task Force on Climate-Related Financial Disclosures (TCFD)

TCFD developed globally recognized recommendations for consistent, comparable climate-related financial disclosures to aid investors and stakeholders in assessing risks and opportunities.