Glossary of Terms

A pathway of emissions of greenhouse gasses and other climate forcers that provides an approximately one-in-two to two-in-three chance, given current knowledge of the climate response, of global warming either remaining below 1.5°C or returning to 1.5°C by around 2100 following an overshoot. See also Temperature overshoot.

Target is aligned with scenarios that yield a long-term warming outcome of <1.5C with some probability (e.g. 50%, 66%) and some amount of overshoot (no/low), both of which should be explicitly specified.

Reduction in the amount, degree or intensity of emissions of CO2 or other pollutants

When no greenhouse gas emissions are attributable to an organization’s activities across all scopes.

Planting of new forests on lands that historically have not contained forests. For a discussion of the term forest and related terms such as afforestation, reforestation and deforestation, see the IPCC Special Report on Land Use, Land-Use Change, and Forestry (IPCC, 2000) information provided by the United Nations Framework Convention on Climate Change (UNFCCC, 2013) and the report on Definitions and Methodological Options to Inventory Emissions from Direct Human-induced Degradation of Forests and Devegetation of Other Vegetation Types (IPCC, 2003)

Emissions of greenhouse gasses caused by human activities. These activities include the burning of fossil fuels, deforestation, land use and land-use changes, livestock production, fertilization, waste management and industrial processes.

The withdrawal of greenhouse gasses from the atmosphere as a result of deliberate human activities. These include enhancing biological sinks of carbon dioxide and using chemical engineering to achieve long-term removal and storage. Carbon capture and storage from industrial and energy-related sources, which alone does not remove carbon dioxide in the atmosphere, can reduce atmospheric carbon dioxide if it is combined with bioenergy production.

Greenhouse gas emission reduction that occurs outside the organizational boundaries of the reporting organization as a direct consequence of the use of its products.

Energy derived from biomass

A process in which a relatively pure stream of carbon dioxide from industrial and energy-related sources is separated (captured), conditioned, compressed and transported to a storage location for long-term isolation from the atmosphere. Sometimes referred to as carbon capture and storage.

A process in which carbon dioxide is captured and then used to produce a new product. If the carbon dioxide is stored in a product for a climate-relevant time horizon, this is referred to as carbon dioxide capture, utilization and storage (CCUS). Only then, and only combined with carbon dioxide recently removed from the atmosphere, can CCUS lead to carbon dioxide removal. CCU is sometimes referred to as carbon dioxide capture and use.

Unit for comparing the radiative forcing of a greenhouse gas (3.9.1) to that of carbon dioxide.

Anthropogenic activities removing carbon dioxide from the atmosphere and durably storing it in geological, terrestrial, or ocean reservoirs, or in products. It includes existing and potential anthropogenic enhancement of biological or geochemical sinks and direct air capture and storage, but excludes natural carbon dioxide uptake not directly caused by human activities.

When an organization’s greenhouse gas removals, internal and external, exceed its emissions and any removals are “like for like.” Must be specified over a declared time period, and whether removals and emissions are cumulative or represent only the time period specified

Achieved when anthropogenic carbon dioxide emissions are balanced globally by anthropogenic carbon dioxide removals over a specified period. A period of time in which there has been no net increase in the global emission of greenhouse gasses to the atmosphere as a result of the greenhouse gas emissions associated with the subject during the same period.

Mechanism for compensating for all or for a part of the carbon footprint through the prevention of the release< of, reduction in, or removal of an amount of greenhouse gas emissions in a process outside the product system or organizational boundaries.

The process of storing carbon in a carbon pool.

A reservoir (natural or human, in soil, ocean, and plants) where a greenhouse gas, an aerosol or a precursor of a greenhouse gas is stored. Note that UNFCCC Article 1.8 refers to a sink as any process, activity or mechanism which removes a greenhouse gas, an aerosol or a precursor of a greenhouse gas from the atmosphere.

Climate change refers to a change in the state of the climate that can be identified (e.g., by using statistical tests) by changes in the mean and/or the variability of its properties and that persists for an extended period, typically decades or longer. Climate change may be due to natural internal processes or external forcings such as modulations of the solar cycles, volcanic eruptions and persistent anthropogenic changes in the composition of the atmosphere or in land use. Note that the Framework Convention on Climate Change (UNFCCC), in its Article 1, 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.’ The UNFCCC thus makes a distinction between climate change attributable to human activities altering the atmospheric composition and climate variability attributable to natural causes

Concept of a state in which human activities result in no net effect on the climate system. Achieving such a state would require balancing of residual emissions with emission (carbon dioxide) removal as well as accounting for regional or local biogeophysical effects of human activities that, for example, affect surface albedo or local climate.

When an organization’s greenhouse gas removals, internal and external, exceed its emissions and any removals are “like for like.” Must be specified over a declared time period, and whether removals and emissions are cumulative or represent only the time period specified

Climate Neutrality – A “point in time” statement, where organizations begin measuring emissions, setting science-based reduction plans, abating emissions in line with these set targets, and only then compensating for unavoidable emissions through carbon offsets. More comprehensive than carbon neutrality, climate neutrality encompasses more greenhouse gases (GHGs) than just carbon but is not as rigorous as “net zero.” Both climate or carbon neutrality are less rigorous than net-zero in that carbon offsets reduce unavoidable emissions up until the point of achieving neutrality, but do not go so far as to physically extract carbon from the atmosphere (carbon removal).

Net Zero – A corporate standard that builds upon climate neutrality by broadening the scope of emission reduction activities to emissions beyond the direct corporate value chain. Like climate neutrality, there is an emission reduction trajectory for the value chain, but net-zero urges organizations to go further by investing in projects that physically extract and prevent further emissions, essentially acting as a cure for emissions. Once emissions are as close as possible to zero, any further unavoidable emissions are eradicated not with carbon offsets, but with natural and artificial carbon removals. Carbon removal doesn’t just offset the exact amount of carbon you need to achieve neutrality, but physically removes carbon from the atmosphere forever, whether through carbon capture or optimizing natural carbon sinks, thus going farther than offsetting and allowing you to achieve “net zero.” Ideally, net zero should employ solely carbon removals with no offsets at all.

Climate Positive/Carbon Negative – The destination we strive for after achieving net zero. After all reduction plans have been implemented and only few unavoidable emissions remain, climate positive or carbon negative encompasses removing more GHGs than what is left, creating a net-positive.

Reducing GHG emissions, or increasing GHG removals through activities outside of an organization’s emissions inventory, in order to compensate for GHG emissions such that an organization’s net contribution to global emissions is reduced. Compensation claims are only valid under a rigorous set of conditions, including that the reductions/removals involved are additional, not over-estimated, and exclusively claimed. Includes offsetting, but also all other activities an organization makes outside its value chain that are contributions to mitigation.

The total amount of emissions released over a specified period of time.

The process by which countries, individuals or other entities aim to achieve zero fossil carbon existence. Typically refers to a reduction of the carbon emissions associated with electricity, industry and transport.

Conversion of forest to non-forest. For a discussion of the term forest and related terms such as afforestation, reforestation and deforestation, see the IPCC Special Report on Land Use, Land-Use Change, and Forestry (IPCC, 2000). See also information provided by the United Nations Framework Convention on Climate Change (UNFCCC, 2013) and the report on Definitions and Methodological Options to Inventory Emissions from Direct Human-induced Degradation of Forests and Devegetation of Other Vegetation Types (IPCC, 2003)

Chemical process by which carbon dioxide is captured directly from the ambient air, with subsequent storage.

Emissions that physically arise from activities within well-defined boundaries of, for instance, a region, an economic sector, a company, or a process.

Greenhouse gas removal from greenhouse gas sinks owned or controlled by the organization.

A category of contractual instrument that represents certain information (or attributes) about the energy generated, but does not represent the energy itself. This category includes a variety of instruments with different names, including certificates, tags, credits, or generator declarations.

Carbon-based fuels from fossil hydrocarbon deposits, including coal, oil, and natural gas.

Where GHG emissions attributable to an organization are fully compensated by GHG reductions or removals exclusively claimed by the organization, such that their net contribution to global GHG emissions is zero, irrespective of the time period or the relative magnitude of emissions and removals involved.

Actions that remove GHGs from the atmosphere relative to baseline.

The estimated increase in global mean surface temperature (GMST) averaged over a 30-year period, or the 30-year period centered on a particular year or decade, expressed relative to pre-industrial levels unless otherwise specified.

Quantified decrease in greenhouse gas emissions between a baseline scenario and the project

Greenhouse gases are those gaseous constituents of the atmosphere, both natural and anthropogenic, that absorb and emit radiation at specific wavelengths within the spectrum of infrared radiation emitted by the Earth’s surface, the atmosphere, and clouds. 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 Earth’s atmosphere. Moreover, there are a number of entirely human-made greenhouse gases in the atmosphere, such as the halocarbons and other chlorine and bromine-containing substances which are dealt with under the Montreal Protocol. Beside CO2 , N2O, and CH4 , the Kyoto Protocol deals with the greenhouse gases sulfur hexafluoride (SF6 ), hydrofluorocarbons (HFCs) and perfluorocarbons (PFCs).

Emissions that are a consequence of the activities within well-defined boundaries of, for instance, a region, an economic sector, a company or process, but which occur outside the specified boundaries. For example, emissions are described as indirect if they relate to the use of heat but physically arise outside the boundaries of the heat user, or to electricity production but physically arise outside of the boundaries of the power supply sector

When a source of emissions and an emissions sink correspond in terms of their warming impact, and in terms of the timescale and durability of carbon storage. For example, fossil carbon is stable in the lithosphere over millennia if it is not extracted and burned, therefore mitigating measures (e.g. offsets) that aim to neutralize the effect of these emissions must persist for a comparable, geological-timescale. Although all CO2 once emitted, whether originally sourced from the lithosphere or biosphere, persists in the active carbon cycle for centuries to millennia, it may be appropriate to balance shorter-duration carbon released from biogenic carbon stocks (e.g. forests and soils) with comparably temporary storage in like stocks. The variable risks of reversal of different carbon stocks must also be considered, for example forests may suffer from unforeseen anthropogenic (e.g. illegal logging), non-anthropogenic (e.g. disease and disaster), or climate change-induced (e.g. warming) reversal risks.

Removal of greenhouse gases (GHGs) from the atmosphere by deliberate human activities, i.e., in addition to the removal that would occur via natural carbon cycle processes.

Net zero carbon dioxide (CO2) emissions are achieved when anthropogenic CO2 emissions are balanced globally by anthropogenic CO2 removals over a specified period. Net zero CO2 emissions are also referred to as carbon neutrality. See also Net zero emissions and Net negative emissions.

Net zero emissions are achieved when anthropogenic emissions of greenhouse gases to the atmosphere are balanced by anthropogenic removals over a specified period. Where multiple greenhouse gases are involved, the quantification of net zero emissions depends on the climate metric chosen to compare emissions of different gases (such as global warming potential, global temperature change potential, and others, as well as the chosen time horizon).

GHG removals outside an organization’s emissions inventory, that balance residual GHG emissions such that an organization’s net contribution to global emissions is reduced or eliminated. Neutralization claims are only valid under a rigorous set of conditions, including that the reductions/removals involved are additional, not over-estimated, exclusively claimed, and like for like. May include offsetting, but also all other activities an organization makes outside its value chain that are contributions to mitigation.

Reducing GHG emissions (including through avoided emissions), or increasing GHG removals through activities external to an organization, in order to compensate for GHG emissions, such that an organization’s net contribution to global emissions is reduced. Offsetting is typically arranged through a marketplace for carbon credits or other exchange mechanisms. Offsetting claims are only valid under a rigorous set of conditions, including that the reductions/removals involved are additional, not over-estimated, and exclusively claimed. Further, offsetting can only be used to claim net zero status to the extent it is “like for like” with any residual emissions. See also compensation and neutralization.

Targets are considered ‘Paris-aligned’ if they are in line with what the latest climate science deems necessary to meet the goals of the Paris Agreement – limiting global warming to well-below 2°C above pre-industrial levels and pursuing efforts to limit warming to 1.5°C, with no or low overshoot. Refers to mitigation targets of the Paris Agreement only.

Pathways is the temporal evolution of natural and/or human systems towards a future state. Pathway concepts range from sets of quantitative and qualitative scenarios or narratives of potential futures to solution-oriented decision-making processes to achieve desirable societal goals. Pathway approaches typically focus on biophysical, techno-economic, and/or socio-behavioral trajectories and involve various dynamics, goals and organizations across different scales.

Planting of forests on lands that have previously contained forests but that have been converted to some other use. For a discussion of the term forest and related terms such as afforestation, reforestation and deforestation, see the IPCC Special Report on Land Use, Land-Use Change, and Forestry (IPCC, 2000), information provided by the United Nations Framework Convention on Climate Change (UNFCCC, 2013), the report on Definitions and Methodological Options to Inventory Emissions from Direct Human-induced Degradation of Forests and Devegetation of Other Vegetation Types (IPCC, 2003)

A market-based instrument that represents the property rights to the environmental, social and other non-power attributes of renewable electricity generation.

Emissions remaining after all technically and economically feasible opportunities to reduce emissions in all covered scopes and sectors have been implemented.

Targets are considered ‘science-based’ if they are in line with what the latest climate science deems necessary to meet the goals of the Paris Agreement – limiting global warming to well-below 2°C above pre industrial levels and pursuing efforts to limit warming to 1.5°C, with no or low overshoot.

‘Scope 1’ indicates direct greenhouse gas emissions that are from sources owned or controlled by the reporting entity.

‘Scope 2’ indicates indirect greenhouse gas emissions associated with the production of electricity, heat, or steam purchased by the reporting entity.

‘Scope 3’ indicates all other indirect emissions, i.e., emissions associated with the extraction and production of purchased materials, fuels, and services, including transport in vehicles not owned or controlled by the reporting entity, outsourced activities, waste disposal, etc. Scope 3 emissions are a consequence of the activities of the company, but occur from sources not owned or controlled by the company

The temporary exceedance of a specified level of global warming, such as 1.5°C. Overshoot implies a peak followed by a decline in global warming, achieved through anthropogenic removal of CO2 exceeding remaining CO2 emissions globally.

Not captured by carbon sequestration or storage

The zero emissions commitment is the climate change commitment that would result from setting anthropogenic emissions to zero. It is determined by both inertia in physical climate system components (ocean, cryosphere, land surface) and carbon cycle inertia.