Glossaries

Climate Change Glossary

Simplified Terminology for the Forest Products Industry

Climate Change is defined by the United Nations Framework Convention on Climate Change (UNFCCC) as “A change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods.”

This page lists nearly 100 terms that appear frequently in news and journal articles on the topic of climate change. The definitions provided are simple and straightforward, and, where possible, highlight a term’s specific relevance to the forest products industry.  While these definitions have been simplified, NCASI staff are able to provide more detailed explanation upon request. For some terms, the definition is followed by a reference link to specific organizational, technical, and/or published definitions.

Throughout the glossary, the term “greenhouse gas” is abbreviated as GHG. The plural form, GHGs, refers to more than one type of greenhouse gas.

This page will be updated periodically with new terms, improved explanations, and updated definition references.

For more information, contact Adam Costanza.


A

Adaptive Capacity

Adaptive capacity is the ability of a system to adjust to the effects of climate change in ways that moderate potential damages, to take advantage of opportunities, or to cope with the consequences. A system with a high adaptive capacity (e.g., coastal saltwater marsh) could better handle the consequences of climate-induced sea level rise than a system with low adaptive capacity (e.g., a beach-side golf course).
Reference: U.S. National Climate Assessment

 Additionality

Carbon offset activities or projects are considered additional if they would not occur under a business-as-usual scenario. Offset projects have additionality requirements to ensure that the ton of emissions reductions used as an offset is fully equivalent to a ton of emissions. Additionality tests aim to validate the claim that a generated offset is uniquely responsible for making a verifiable reduction in emissions that only occurred because the project exists. Note that there is no requirement to demonstrate additionality when applying renewable energy credits (RECs) to an organization’s market-based Scope 2 emissions.
Reference: The Greenhouse Gas Protocol

Annex I Countries/Parties

Annex I Parties include the industrialized countries that were members of the OECD (Organization for Economic Co-operation and Development) in 1992, plus countries with economies in transition. Annex I countries commit themselves to returning individually or jointly to their 1990 levels of greenhouse gas emissions. Annex I parties committed to GHG emission reductions under the Kyoto Protocol.
References: Annex 1 Parties | Kyoto Protocol

Anthropogenic

Anthropogenic means “made by people” or “resulting from human activities.” Anthropogenic is usually used in the context of emissions that are produced as a result of human activities, as in anthropogenic GHG emissions.
Reference: U.S. EPA

Avoided Emissions

Emission reductions that are indirectly caused by a product or process that occurs outside the life cycle or value chain, and are a result of the use of that product or process. Alternative terminologies include climate positive, net-positive accounting, Scope 4 emissions, and substitution effects.
Reference: NCASI Whitepaper

B

Baseline Scenario

A baseline scenario is a hypothetical reference case of conditions that would most likely occur in the absence of climate change mitigation. Baseline scenarios can also be referred to as ”business as usual” scenarios. For example, if a mill had a coal boiler in good working order that was generating process steam, and the company decided to convert it to natural gas to reduce GHG emissions, the baseline scenario would be the emission profile of the coal boiler.
Reference: The Greenhouse Gas Protocol

Biogenic Carbon

The carbon embodied in or derived from biomass is biogenic carbon. An emission factor of zero is normally used for biogenic CO2, meaning it is GHG neutral, reflecting guidance from the Intergovernmental Panel on Climate Change (IPCC) for the preparation of national greenhouse gas inventories (IPCC 2006).
Reference: NCASI Technical Bulletin 1015

Business as Usual

See Baseline Scenario.

C

Cap and Trade

Cap and trade is a policy tool for controlling large amounts of emissions from a group of sources. A cap and trade program first sets a cap, or maximum limit, on emissions. Sources covered by the program then receive authorizations to emit in the form of emissions allowances, with the total amount of allowances limited by the cap. Each source can design its own compliance strategy to meet the overall reduction requirement, including the sale or purchase of allowances, installation of pollution controls, and implementation of efficiency measures, among other options dictated by the program.
Reference: U.S. EPA

Carbon

Carbon is a chemical element. In the context of climate change and GHG emissions, “carbon” should not be used interchangeably with carbon dioxide (CO2). While carbon may be used as a shorthand for carbon dioxide, it is not correct. A ton of carbon is not a ton of CO2. Though you may occasionally find these terms used interchangeably, it is not correct to do so. The atomic weight of carbon is 12 atomic mass units, while the weight of carbon dioxide is 44, because it includes two oxygen atoms, each with an atomic mass of 16. Thus, one ton of combusted carbon is equivalent to 44/12 = 11/3 = 3.67 tons of CO2, and 11 tons of CO2 is equivalent to 3 tons of carbon. Likewise, a price of $30 per ton of CO2 equals a price of $110 per ton of carbon.

Carbon Capture and Storage (or Sequestration)

Carbon capture and storage (CCS) is a set of technologies designed to reduce carbon dioxide (CO2) emissions from fossil fuel combustion, industrial processes, and other stationary sources of carbon dioxide. CCS is a three-step process that includes 1) capture of carbon dioxide from power plants or industrial sources, 2) transport of the captured and compressed carbon dioxide, and 3) underground or deep-sea injection of that carbon dioxide to trap and hold the carbon dioxide for long periods of time. Bioenergy Carbon Capture and Storage (BECCS) emphasizes bioenergy (BE) as the fuel source with CCS that can result in negative carbon emissions.
Reference: U.S. National Climate Assessment

Carbon Credit

A credit that allows the holder to emit an amount of carbon dioxide (CO2) or carbon dioxide equivalent (CO2e) (typically one ton). The credit may be a permit or a tradeable certificate.
Reference: ISO 14068

Carbon Cycle

The carbon cycle on Earth includes all parts (reservoirs) and fluxes of carbon. The carbon cycle represents circulation of carbon atoms through the Earth’s systems as a result of photosynthetic conversion of carbon dioxide (CO2) into complex organic compounds by plants, which are consumed by other organisms, and return of the carbon to the atmosphere as carbon dioxide as a result of respiration, decay of organisms, and combustion of fossil fuels. The cycle includes four main reservoirs of carbon interconnected by pathways of exchange. The reservoirs are the atmosphere and terrestrial biosphere, which is inclusive of freshwater systems, oceans, sediments, and fossil fuels. The annual movements of carbon, meaning the carbon exchanges between reservoirs, occur because of chemical, physical, geological, and biological processes.
Reference: U.S. National Climate Assessment

Carbon Dioxide (CO2)

Carbon dioxide (CO2) is a primary greenhouse gas (GHG). Other climate-forcing gases are compared to CO2 and normalized against it to develop ”Global Warming Potentials” and carbon dioxide equivalents (CO2e).

Carbon Dioxide Equivalent (CO2e)

Carbon dioxide equivalent (CO2e) is a measure used to compare the emissions from various greenhouse gases based on their global warming potential. For example, as per The Intergovernmental Panel on Climate Change (IPCC) 6th Assessment Report, the global warming potential (GWP) for methane from fossil fuels over 100 years is 29.8. This means that emissions of one million metric tons of methane from fossil fuels is equivalent to emissions of 29.8 million metric tons of carbon dioxide. Units for carbon dioxide equivalents can be expressed as “million metric tons of carbon dioxide equivalents (MMTCO2Eq),” or other abbreviated expressions denoting mass and CO2e. The carbon dioxide equivalent for a gas is derived by multiplying the tons of the gas by the associated GWP: MMTCO2Eq = (million metric tons of a gas) * (GWP of the gas).
References: IPCC 6th Assessment | U.S. EPA

Carbon Dioxide Fertilization

The enhancement of the growth of plants as a result of increased atmospheric CO2 concentration.
Reference: UN Food and Agriculture Organization (FAO)

Carbon Footprint

The net total amount of GHG emissions and removals into the atmosphere over a set period of time by a person, family, building, organization, company, product, or activity. A carbon footprint is the result of a calculation that sums GHG emissions and removals.  The footprint calculation can be for as long as a lifetime (in the case of a product) or as short as minutes (in the case of a car ride). The boundaries of a particular carbon footprint can vary in time and scope. When boundary conditions are not explicitly detailed, product carbon footprints typically cover the lifetime of the product and are inclusive of upstream and downstream activities associated with the product’s manufacture and end of life. It is common for the carbon footprint of a forest product to include:

  1. Biomass carbon removal and storage in forests
  2. Biomass carbon in paper and board products
  3. Greenhouse gas emissions from paper and board product manufacturing facilities
  4. Greenhouse gas emissions associated with producing wood fiber
  5. Greenhouse gas emissions associated with producing other raw materials/fuels
  6. Greenhouse gas emissions associated with purchased electricity, steam, heat, and hot and cold water
  7. Greenhouse gas emissions associated with transportation
  8. Greenhouse gas emissions associated with product use
  9. Greenhouse gas emissions associated with product end of life

A tenth category, avoided greenhouse gas emissions, may also be included in some carbon footprint boundaries.
Reference: The European association representing the paper industry (Cepi)

Carbon Negative

An activity or operation is considered to be carbon negative if the sum of carbon emissions and carbon removals associated with it is less than zero. If something is carbon negative, whether it is a product or a process, the atmosphere contains less greenhouse gas because of it, meaning that without that product or process, there would be more GHGs in the atmosphere.  Carbon negative is often synonymous with “GHG Negative” or “Climate Negative.”
Reference: International Energy Agency

Carbon Neutral

“Carbon neutrality,” or “net zero,” means that any CO2 released into the atmosphere from human activity is balanced by an equivalent amount being removed.
Reference: International Energy Agency

Carbon Neutrality

The state of being carbon neutral.

Carbon Offsets

Verified avoided GHG emissions, GHG emission reductions, or GHG removals that are made available to another organization in the form of a carbon credit to balance (as in reduce) GHG emissions. Some offsets are calculated relative to a baseline scenario that represents a hypothetical scenario for what GHG emissions would have been in the absence of the mitigation project that generates the offsets.
Reference: ISO 14068

Carbon Removals

See Carbon Sequestration.

 Carbon Sequestration

Carbon sequestration is the process of removing carbon dioxide (CO2) from the atmosphere and storing it either through terrestrial, biologic, or geologic mechanisms. For example, trees and plants absorb CO2, release the oxygen (O2), and store the carbon (C) in their tissues. Geologic sequestration is a step in the process of carbon capture and sequestration (CCS) that involves injecting carbon dioxide deep underground. An organism, landscape, or operation that stores carbon is a carbon sink.
Reference: U.S. EPA

Carbon Sink

A carbon sink is any system that absorbs more carbon than it emits. The main natural carbon sinks are forests, soil, and oceans.
Reference: U.S. National Climate Assessment

Climate Action Commitment

A commitment made by an organization that sets out specific, time-bound climate change mitigation actions that will be taken.
Reference: Science Based Targets

Climate Change

The United Nations Framework Convention on Climate Change (UNFCCC) defines climate change as, “A change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods.”
Reference: UNFCCC

Climate Change Mitigation

Active human intervention to reduce GHG emissions or increase GHG removals.
Reference: ISO 14068

Climate Feedback

A process that acts to amplify or reduce direct warming or cooling effects. An example of climate feedback would be warmer winter temperatures that allow permafrost to melt, which releases methane previously trapped by the permafrost. Methane in turn is a powerful GHG that contributes to climate change.
Reference: U.S. National Climate Assessment

Climate Forcing

A process that alters the energy balance of the climate system is a forcing mechanism. Climate forcing usually refers to changes in the relative balance between incoming solar radiation and outgoing infrared radiation from Earth. Such mechanisms include changes in solar irradiance, volcanic eruptions, and enhancement of the natural greenhouse effect by emissions of GHGs.
Reference: U.S. National Climate Assessment

 Climate Justice

A term used by the United Nations and other organizations that frames climate change as a social and political issue rather than solely an environmental one. According to the UN, climate change disproportionately affects those nations where the average income is much lower than in industrial nations and would have a much greater impact on populations in countries in Africa and Asia.
Reference: United Nations Environment Programme

 Climate Mitigation

Climate mitigations are human interventions to reduce the anthropogenic impacts on the climate system. Climate mitigation includes strategies to reduce GHG sources and emissions, and enhance greenhouse gas sinks.
Reference: U.S. National Climate Assessment

Climate Model

Climate models are used to simulate the effects of GHG emissions on Earth’s climate over time. Also known as general circulation models or GCMs, climate models use mathematical equations to characterize how energy and matter interact in different parts of the ocean, atmosphere, and land. Climate models can be discussed in terms of a Global Climate Model (also referred to as a General Circulation Model, both abbreviated as GCM).
Reference: U.S. National Oceanic and Atmospheric Administration

Climate Neutral

Synonymous with Carbon Neutral.

Climate System

The climate system is a dynamic system consisting of five major components: the atmosphere, the hydrosphere, the cryosphere, the land surface, and the biosphere. These components are influenced by various external “forcing” mechanisms, the most important being the sun. Anthropogenic activities having effects on the climate system are also considered a forcing mechanism.
Reference: The Intergovernmental Panel on Climate Change (IPCC)

Climate Variability

Natural changes in climate that fall within the observed range of extremes for a particular region, as measured by temperature, precipitation, and frequency of events. Drivers of climate variability include the El Niño Southern Oscillation and other phenomena.
Reference: U.S. National Climate Assessment

Climate Velocity

Climate velocity is a metric that quantifies the distance and direction an organism must move over a specified time to keep pace with climate change. Climate velocity is measured by comparing current climate to future climate projections. Climate velocity helps guide conservation efforts by showing which specific areas may see the most rapid pace of climate change, and thus where species will need to move long distances over time to maintain a constant climate. For example, where climate velocity is high, trees will need to shift their ranges over long distances relatively quickly to track suitable climates.
Reference: U.S. National Climate Assessment

Cradle-to-gate

An assessment that includes part of the product’s life cycle, including material acquisition through the production of the studied product and excluding the use or end-of-life stages.

Cradle-to-grave

A cradle-to-grave assessment considers impacts at each stage of a product’s life cycle, from the time natural resources are extracted from the ground and processed through each subsequent stage of manufacturing, transportation, product use, recycling, and end-of-life.

D

Direct Emissions

Emissions from sources owned or controlled by the entity.
Reference: The Greenhouse Gas Protocol

Displacement Factor

See Substitution Factor.

 E

Emissions

Emissions are the release of a substance (usually a GHG when referring to the subject of climate change) into the atmosphere.

Emission Factors

Emission factors are values for scaling emissions to activity data in terms of a standard rate of emissions per unit of activity. For example, kilograms of carbon dioxide emitted per barrel of fossil fuel consumed, or kilograms of carbon dioxide emitted per ton of product produced.
Reference: XBRL Units Registry

 Emissions Scenarios

Quantitative illustrations of how the release of different amounts of GHGs into the atmosphere from human and natural sources will produce different future climate conditions. Scenarios are developed using a wide range of assumptions about population growth, economic and technological development, and other factors.
Reference: U.S. National Climate Assessment

Emissions Trading

A pollution reduction approach that enables industrial emitters to purchase reductions made by other entities and use those reductions as part of meeting their emissions compliance. Emissions trading programs have two key components: a limit (or cap) on pollution, and tradable allowances equal to the limit that authorize allowance holders to emit a specific quantity (e.g., one ton) of the pollutant. This limit ensures that the environmental goal is met and the tradable allowances provide flexibility for individual emissions sources to set their own compliance path. Because allowances can be bought and sold in an allowance market, these programs are often referred to as “market-based.”
Reference: U.S. EPA

End-of-Life

The final disposition of a product. For GHG emission purposes, the end of a product’s life has the potential to generate GHG emissions. For example, forest products disposed of in uncapped landfills can emit carbon dioxide (CO2) or methane over time. End-of-life GHG emissions are included in cradle-to-grave analyses but are not included in cradle-to-gate analyses.

 F

Fossil Fuel

A generic term for organic materials formed from decayed plants and animals that have been converted to crude oil, coal, natural gas, or heavy oils by exposure to heat and pressure in the Earth’s crust over millions of years. Burning fossil fuels is an anthropogenic process.

G

General Circulation (or Climate) Model (GCM)

A global, three-dimensional computer model of the climate system that can be used to simulate human-induced climate change. GCMs are complex and represent the effects of multiple factors, including reflective and absorptive properties of atmospheric water vapor, GHG concentrations, clouds, annual and daily solar heating, ocean temperatures, and ice boundaries. The most recent GCMs include global representations of the atmosphere, oceans, and land surface. See also Climate Model.
Reference: U.S. National Oceanic and Atmospheric Administration

Geo-engineering

Also referred to as climate engineering, geo-engineering is the deliberate and large-scale intervention in the Earth’s climate system with the goal of limiting climate change impacts. Climate engineering interventions generally fall into two broad categories: removing carbon dioxide from the atmosphere or solar radiation management.
Reference: University of Oxford

 Global Change

Changes in the global environment that may alter the capacity of the Earth to sustain life. Global change encompasses climate change, but it also includes other critical drivers of environmental change that may interact with climate change, such as land use change, the alteration of the water cycle, changes in biogeochemical cycles, and biodiversity loss.
Reference: U.S. National Climate Assessment

Global Warming

The observed increase in average temperature near the Earth’s surface and in the lowest layer of the atmosphere. In common usage, global warming often refers to the warming that has occurred as a result of increased emissions of GHGs from human activities (anthropogenic GHG emissions). Global warming is a type of climate change; it can also lead to other changes in climate conditions, such as changes in precipitation patterns.
Reference: U.S. National Climate Assessment

Global Warming Potential (GWP)

The Global Warming Potential (GWP) was developed to allow comparisons of the global warming impacts of different gases. Specifically, it is a measure of how much energy the emissions of 1 ton of a gas will absorb over a given period of time, relative to the emissions of 1 ton of carbon dioxide (CO2). The larger the GWP, the more that a given gas warms the earth compared to CO2 over that time period. The time period often used for GWPs is 100 years. CO2 by definition has a GWP of 1 regardless of the time period used, because it is the gas used as the reference.
Reference: Intergovernmental Panel on Climate Change (IPCC) 6th Assessment

Greenhouse Effect

Greenhouse gases absorb thermal infrared radiation emitted by the Earth’s surface, by the atmosphere itself due to the same gases, and by clouds. Atmospheric radiation is emitted to all sides, including downward to the Earth’s surface. This results in GHGs trapping heat within the surface-troposphere system, called the greenhouse effect. An increase in the concentration of greenhouse gases leads to an increased infrared opacity of the atmosphere and a temperature increase of the surface-troposphere system. This radiative forcing leads to an enhancement of the effectiveness of the greenhouse effect and is called the enhanced greenhouse effect.
Reference: U.S. National Climate Assessment

Greenhouse Gases (GHGs)

Greenhouse gases are constituents of the atmosphere, both natural and anthropogenic, which absorb and emit radiation within the spectrum of thermal infrared radiation. This property causes the greenhouse effect. Water vapor (H2O), carbon dioxide (CO2), nitrous oxide (N2O), methane (CH4), and ozone (O3) are the primary greenhouse gases in the atmosphere. There are additional GHGs identified by various protocols such as sulfur hexafluoride (SF6), hydrofluorocarbons (HFCs), and perfluorocarbons(PFCs). Each GHG has a Global Warming Potential (GWP).
Reference: U.S. National Climate Assessment

Greenhouse Gas Capture

The process of collecting GHGs from a source of emissions before they enter the atmosphere. By itself, GHG capture does not necessarily include GHG storage.

Greenhouse Gas Emission Reduction

A decrease in GHG emissions from one point in time to another as the result of an activity.

Greenhouse Gas Negative

An activity or operation is GHG negative if it removes or sequesters more GHGs than are emitted, such that over a specified period of time there is a net decrease in GHG emissions when all aspects of the activity are summed, which can include carbon offsets. An example in the forest products industry is a bioenergy process with carbon capture and storage (CCS). Greenhouse gas negative is synonymous with ”carbon negative.”
References: International Energy Agency | U.S. National Climate Assessment

Greenhouse Gas Neutral

Synonymous with Carbon Neutral.

Greenhouse Gas Positive

An activity or operation that emits more GHGs than it sequesters.

GHG Protocol

The Greenhouse Gas Protocol (GHG Protocol) was developed through a partnership between the World Resources Institute (WRI) and the World Business Council for Sustainable Development (WBCSD). The GHG Protocol provides accounting and reporting standards, sector guidance, calculation tools, and training for businesses and government. It establishes a comprehensive, global, standardized framework for measuring and managing emissions from private and public sector operations, value chains, products, cities, and policies. The GHG Protocol divides emissions into three Scopes:

Scope 1 – Direct GHG emissions
Scope 2 – Indirect emissions from the generation of purchased electricity and steam
Scope 3 – Other indirect GHG emissions not covered by Scope 1 and Scope 2
Reference: The Greenhouse Gas Protocol

Greenhouse Gas Removal

The process of withdrawing GHGs from the atmosphere by GHG sinks.
Reference: ISO 14068

Greenhouse Gas Reservoir

Anything, except the atmosphere, that has the capacity to accumulate GHGs. A GHG reservoir can store and release GHGs over time. The atmosphere is excluded as a reservoir in this context.
Reference: ISO 14068

Greenhouse Gas Sink

A process that removes GHGs from the atmosphere. A growing forest is a GHG sink.
Reference: ISO 14068

I

Indirect Emissions

There are two types of indirect emissions when accounting for GHG emissions. One type of indirect emissions occurs as a result of the generation of electricity or steam purchased (not generated on-site) and used in operations, buildings, or processes. These emissions are indirect because the emissions occur at facilities generating the electricity or steam, and are not generated by the end user. Under the Greenhouse Gas Protocol, indirect emissions fall within Scope 2. The other type of indirect emissions is the result of activities from assets not owned or controlled by the reporting organization, but which are within the organization’s value chain. These indirect emissions are considered Scope 3 emissions and include all sources not within an organization’s Scope 1 and Scope 2 boundary under the Greenhouse Gas Protocol’s definition. The Scope 3 emissions for one organization are the Scope 1 and 2 emissions of another organization. Indirect emissions often represent the majority of an organization’s total GHG emissions.
Reference: The Greenhouse Gas Protocol

Insetting

An action within an organization’s supply chain that results in lower GHG emissions or higher GHG sequestration. Insetting can take the form of a company making investments within their supply chain that lead to measurable and verifiable emissions reductions. This concept is also called a “supply chain intervention.” Insetting may become an effective tool for companies to reduce their Scope 3 emissions.
Reference: American Forest Foundation

Intergovernmental Panel on Climate Change (IPCC)

The IPCC was established jointly by the United Nations Environment Programme and the World Meteorological Organization in 1988. The purpose of the IPCC is to assess information in the scientific and technical literature related to all significant components of climate change. The IPCC draws upon hundreds of the world’s expert scientists as authors and thousands as expert reviewers. Leading experts on climate change and environmental, social, and economic sciences from some 60 nations have helped the IPCC to prepare periodic assessments of the scientific underpinnings for understanding global climate change and its consequences. With its capacity for reporting on climate change, its consequences, and the viability of adaptation and mitigation measures, the IPCC is considered the official advisory body to the world’s governments on the state of the science of the climate change issue.
Reference: The Intergovernmental Panel on Climate Change

K

Kyoto Protocol

The Kyoto Protocol operationalizes the United Nations Framework Convention on Climate Change (UNFCCC) by committing industrialized countries and economies in transition to limit and reduce GHG emissions following individual targets. The Kyoto Protocol was adopted on December 11, 1997, and entered into force on February 16, 2005. Currently, there are 192 Parties to the Kyoto Protocol with binding emission reduction targets for 37 industrialized countries and economies in transition.
Reference: UNFCCC

N

Natural Climate Solutions

Natural climate solutions are conservation, restoration, and improved land management actions that increase carbon storage or avoid GHG emissions in landscapes and wetlands across the globe. Forests are effective options for natural climate solutions.
Reference: American Forest Foundation

Negative Carbon Emissions

See Carbon Negative.

Net Zero

Often used synonymously with “carbon neutral.” Both “net zero” and “carbon neutral” mean balancing the amount of carbon released with an equivalent amount of carbon sequestered or offset. However, “net zero” is more comprehensive a term because it unambiguously includes all greenhouse gases. Net zero can include commitments from an organization working towards eliminating its GHG footprint. Net zero is used by Science Based Targets (SBTi) and other greenhouse gas focused frameworks in the context of the company’s GHG commitments.
References: Science Based Targets

O

Offsets

Offsets are verified GHG emissions reductions used to address direct and indirect emissions at additional, external projects. The unit of an offset is typically a metric ton of CO2e and simply called a carbon offset. Offsets are subtracted from organizational emissions to determine net organizational emissions. Offsetting is the process of generating or purchasing offsets. Offsets are a subset of avoided emissions by making the project the central component of emission reduction, whereas avoided emissions can also refer to a comparison of emissions not associated with a specific project.
Reference: The Greenhouse Gas Protocol

R

Radiative Forcing

Radiative forcing is a measure of the influence of a particular factor (e.g., greenhouse gases, aerosol, or land use change) on the net change in the Earth’s energy balance.
Reference: U.S. National Climate Assessment

Renewable Energy Certificate (REC)

Renewable Energy Certificates (RECs) are the legal instruments used in renewable electricity and thermal markets to account for renewable electricity and its attributes. RECs are verified by a third party and can be bought and sold between organizations. There are different types of RECs, mainly bundled and unbundled. Bundled RECs convey electricity and the energy attribute (e.g., carbon neutral) whereas unbundled RECs convey only the energy attribute (no actual electricity).
Reference: The Greenhouse Gas Protocol

Representative Concentration Pathways (RCP)

Representative Concentration Pathways (RCP) are computer-based scenarios that include time series of emissions and concentrations of GHGs, aerosols, other chemically active gases, and land use information. The word “representative” signifies that each RCP provides only one of many possible scenarios that would lead to the specific “concentration” (radiative forcing) characteristics. The term “pathway” emphasizes that not only the long-term concentration levels are of interest, but also the trajectory taken over time to reach that outcome.
Reference: U.S. National Climate Assessment

Residual Greenhouse Gas Emissions

Greenhouse gas emissions remaining after achieving some GHG reductions. For example, if a company has a business as usual baseline of emitting 15,000 tons of CO2e per year and is able to remove 5,000 tons of CO2e emissions through various activities, then residual emissions equal 10,000 tons of CO2e per year.
Reference: ISO 14068

S

Scope 1

Scope 1 emissions are direct GHG emissions that occur from sources that are controlled or owned by the reporting organization (e.g., emissions associated with fuel combustion in boilers, furnaces, vehicles), as classified by the Greenhouse Gas Protocol Corporate Standard.
Reference: The Greenhouse Gas Protocol

 Scope 2

Scope 2 emissions are indirect emissions from the generation of purchased energy, including electricity, steam, heat, or cooling, as classified by the Greenhouse Gas Protocol Corporate Standard.
Reference: The Greenhouse Gas Protocol

 Scope 3

Scope 3 emissions are all indirect emissions (not included in Scope 2) that occur in the value chain of the reporting company, including both upstream and downstream emissions, as classified by the Greenhouse Gas Protocol Corporate Standard. Scope 3 emissions include all sources not within an organization’s Scope 1 and 2 boundary. Scope 3 emissions, also referred to as value chain emissions, can represent a large portion of an organization’s total GHG emissions.
Reference: The Greenhouse Gas Protocol

Substitution Effect

Greenhouse gas emissions that would be avoided if a wood-based product is used instead of another product to provide the same function.
Reference: The European Forest Institute

Substitution Factor

A substitution (or displacement) factor describes the GHG emissions that would be avoided if a wood-based product were used instead of another product to provide the same function. For example, using mass timber in a building to substitute for steel or concrete will result in avoided GHG emissions that can be expressed as a substitution factor.
Reference: Canadian Forest Service Pacific Forestry Centre

T

Tipping Point

The point at which a change in the climate triggers a significant environmental event, which may be permanent, such as widespread bleaching of ocean coral or the melting of very large ice sheets.
Reference: U.S. National Climate Assessment

U

United Nations Framework Convention on Climate Change (UNFCCC)

The UN Convention on Climate Change entered into force on March 21, 1994, to set an overall framework for intergovernmental efforts to tackle challenges posed by climate change. The Convention enjoys near universal membership, with 189 countries having ratified it. Under the Convention, governments: 1) gather and share information on greenhouse gas emissions, national policies, and best practices; 2) launch national strategies for addressing GHG emissions and adapting to expected impacts; and 3) cooperate in preparing for adaptation to the impacts of climate change.
Reference: UNFCCC