Glossary

“Conversion to forest of land that historically has not contained forests” (IPCC AR6 WGIII).

The application of carbon capture and storage (CCS) technology to a bioenergy facility. Depending on the total emissions of the BECCS supply chain, BECCS can result in net negative emissions (IPCC AR6 WGIII). Note that numerous non-energy-related sources of biogenic emissions, such as fermentation and biogas digestion, can also generate negative emissions when the resulting […]

A range of methods that use biogenic carbon, such as biomass or a stream of CO2 derived from biomass, to remove carbon dioxide from the atmosphere and store it either underground or in long-lived products (Sandalow et al., 2021).

A unit representing a one tonne of CO2 climate benefit. Carbon credits can either be an avoided emission / emission reduction carbon credit, or a removal carbon credit. If “offsetting” is the verb (the act of compensating for emissions), “carbon credit” is the noun (the unit of account). Carbon credits can be used in other […]

A reservoir in the Earth System allowing for carbon to remain over various periods of time, depending on the specific pool (IPCC AR6 WGIII).

Anthropogenic activities removing CO2 from the atmosphere and durably storing it in geological, terrestrial, or ocean reservoirs, or in products (IPCC WGIII AR6). Carbon removal involves several modules: extraction from the air or upper ocean, conversion into a storable format, transportation, and storage. Carbon dioxide removal is often abbreviated “CDR”. Note that some policy environments […]

A carbon sink is anything, natural or otherwise, that absorbs more carbon from the atmosphere than it releases – for example, plants, the ocean and soil. In contrast, a carbon source is anything that releases more carbon into the atmosphere than it absorbs – for example, the burning of fossil fuels or volcanic eruptions.

“A process in which a relatively pure stream of carbon dioxide (CO2) from industrial and energy-related sources is separated (captured), conditioned, compressed and transported to a storage location for long-term isolation from the atmosphere” (IPCC AR6 WGIII). CCS can be applied to different emissions sources to achieve different climate outcomes. CCS can be applied to fossil power […]

“A process in which carbon dioxide (CO2) is captured and the carbon then used in a product. The climate effect of CCU depends on the product lifetime, the product it displaces, and the CO2 source (fossil, biomass or atmosphere)” (IPCC AR6 WGIII). There are a range of applications for captured CO2 – it can be […]

Carbon dioxide removal, see carbon removal.

An assertion by an entity (government, non-state actor such as a corporation, individual, etc.) that they have generated a positive climate outcome. Compensation claim – An entity claims to have “compensated” for a negative impact by funding an equal and opposite positive impact. Carbon offsetting is the most common form of compensation claim, in which […]

The state in which all negative climate impacts are fully balanced with corresponding compensatory actions, such as through carbon removal and other remediation. Climate neutrality includes all greenhouse gases (think carbon dioxide methane, and nitrous oxide) and other climate impacts (e.g., albedo from land-use change and desertification). While the scientific use of the term is […]

CDR methods that are well established, already deployed at scale and widely reported by countries as part of land use, land-use change and forestry (LULUCF) activities. The methods included in this group are afforestation/reforestation; agroforestry; forest management; soil carbon sequestration in croplands and grasslands; peatland and coastal wetland restoration; and durable wood products (Smith et […]

“Chemical process by which carbon dioxide (CO2) is captured directly from the ambient air, with subsequent storage. Also known as direct air capture and storage (DACS)” (IPCC AR6 WGIII).

The capacity to store carbon over time without releasing it back to the atmosphere (Smith et al., 2024). The durability of a carbon store is governed by the expected longevity and risk of reversal back into the atmosphere. Evidence suggests that less durable forms of carbon removal are significantly less effective in addressing residual emissions, […]

Typically refers to CDR processes that are not based on natural processes. The term does not have a standardised definition. Engineered CDR often refers to methods like DACCS and BECCS that are based on large-scale engineering, but may include a wider range of methods. For example, the UK government includes DACCS, BECCS, biochar, enhanced rock […]

“A proposed method to increase the natural rate of removal of carbon dioxide (CO2 ) from the atmosphere using silicate and carbonate rocks. The active surface area of these minerals is increased by grinding, before they are actively added to soil, beaches or the open ocean” (IPCC AR6 WGIII).

Gaseous constituents of the atmosphere, both natural and anthropogenic, that absorb and emit radiation at specific wavelengths within the spectrum of radiation emitted by the Earth’s surface, by the atmosphere itself, and by clouds. This property causes the greenhouse effect. Water vapour (H2O), carbon dioxide (CO2), nitrous oxide (N2O), methane (CH4) and ozone (O3) are […]

Techniques that capture greenhouse gases from the atmosphere and store or chemically convert them to a stable state with some degree of permanence. Greenhouse gas removal is an umbrella term – it includes carbon removal but also the removal of other greenhouse gases like methane and nitrous oxide (CO2RE, n.d.). See Carbon removal.

Important Projects of Common European Interest (IPCEI) are strategic instruments for the implementation of the European Union (EU) Industrial Strategy.  

The InvestEU Programme supports sustainable investment, innovation and job creation in Europe. It aims to trigger more than €372 billion in additional investment over the period 2021-27.

Intergovernmental Panel on Climate Change

A compilation and evaluation of the inputs, outputs and potential environmental impacts of a product or service throughout its life cycle (IPCC AR6 WGIII).

A GHG inventory sector that covers anthropogenic emissions and removals of GHG from carbon pools in managed lands, excluding non-CO2 agricultural emissions (IPCC WGIII AR6). In the EU, LULUCF emissions are regulated under a dedicated EU instrument, the LULUCF Regulation.

The corresponding process description for each carbon removal method, with associated documentation allowing for the evaluation, measurement, and potential certification of an instance of carbon removal. Methodologies could describe a discrete module of a carbon removal method, such as a particular technique for extraction (sorbent-based direct air capture), or a particular type of storage (injection […]

The prospect of reduced or delayed mitigation resulting from the introduction or consideration of another climate intervention (Markusson, 2018). Carbon Gap has outlined the risks and methods to manage mitigation deterrence in a 2023 report.

Measurement is the process of collecting data over time at appropriate time intervals to provide datasets to quantify the relevant variables; Reporting is the process of formal reporting of assessment results following predetermined formats and established standards to a relevant third party or authority; Verification refers to the process of formal verification of reports based […]

A term used under the United Nations Framework Convention on Climate Change (UNFCCC) whereby a country that has joined the Paris Agreement outlines its plans for reducing its emissions. Some countries’ NDCs also address how they will adapt to climate change impacts, and what support they need from, or will provide to, other countries to adopt low-carbon pathways and […]

“A situation of net negative greenhouse gas emissions is achieved when metric-weighted anthropogenic greenhouse gas (GHG) removals exceed metric-weighted anthropogenic GHG emissions. Where multiple GHG are involved, the quantification of net emissions depends on the metric chosen to compare emissions of different gases (such as global warming potential, global temperature change potential, and others, as […]

“Condition in which metric-weighted anthropogenic greenhouse gas (GHG) emissions are balanced by metric-weighted anthropogenic GHG removals” for a defined region or entity and over a set time period (IPCC AR6 WGIII).

National inventory reports are submitted anually by all nations to the United Nations Framework Convention on Climate Change (UNFCCC), together with the common reporting formats (CRF). The NIRs contain detailed descriptive and numerical information and the CRF tables contain all greenhouse gas (GHG) emissions and removals, implied emission factors and activity data.

Non-fungibility principle refers to CDR methods or to carbon sinks considered as distinct and not interchangeable. For example, “land sinks and geological storage should be considered as non-fungible”.

“CDR methods that generally have a lower level of readiness for deployment and are therefore currently deployed at smaller scales. The captured carbon is stored in geological formations, the ocean or products. Such methods include Bioenergy with Carbon Capture and Storage (BECCS), Direct Air Carbon Capture and Storage (DACCS), enhanced rock weathering, biochar, mineral products […]

“A proposed carbon dioxide removal (CDR) method that involves deposition of alkaline minerals or their dissociation products at the ocean surface. This increases surface total alkalinity, and may thus increase ocean carbon dioxide (CO2) uptake and ameliorate surface ocean acidification” (IPCC AR6 WGIII).

“The reduction, avoidance or removal of a unit of greenhouse gas (GHG) emissions by one entity, purchased by another entity to counterbalance a unit of GHG emissions by that other entity. Offsets are commonly subject to rules and environmental integrity criteria intended to ensure that offsets achieve their stated mitigation outcome. Relevant criteria include, but are not […]

A hypothetical ideal state in which stored carbon persists in perpetuity. There is limited agreement as to how permanent CDR should be defined. In practice, “durability” is a more useful metric (see Durability).

The RRF was conceived to mitigate the impacts of the pandemic and support Europe through the green and digital transitions. The Facility is a temporary recovery instrument. It allows the Commission to raise funds to help Member States implement reforms and investments that are in line with the EU’s priorities and that address the challenges […]

“Conversion to forest of land that has previously contained forests but that has been converted to some other use” (IPCC AR6 WGIII).

“Remaining gross emissions when net-zero, and subsequently, net-negative, emissions are reached […] To reach net-zero emissions, the amount of CDR must equal the amount of residual emissions over a given period. To reach net-negative emissions, the amount of CDR must exceed residual emissions” (Smith et al., 2024).

A reversal occurs when stored carbon escapes and is released back into the atmosphere, reducing or nullifying the climate benefit that has been delivered by the initial instance of removal. Reversals can be non-anthropogenic (“acts of God”, natural disasters such as wildfires) or anthropogenic (caused by human misconduct or negligence, such as illegal logging). The […]

An underlying principle of carbon removal in which stored carbon is at all times the responsibility of an assigned steward. The steward might initially be the entity responsible for storing the removed carbon (e.g., a North Sea geological storage operator under the CCS Directive), with stewardship being reassigned at a later date subject to some […]

Technology readiness level, which according to the International Energy Agency follows a 1-11 scale defined as: 1 – Initial idea (basic principles have been defined) 2 – Application formulated (concept and application of solution have been formulated) 3 – Concept needs validation (solution needs to be prototyped and applied) 4 – Early prototype (prototype proven in test conditions) 5 […]

“The United Nations Framework Convention on Climate Change (UNFCCC) was adopted in May 1992 and opened for signature at the 1992 Earth Summit in Rio de Janeiro. It entered into force in March 1994 and as of May 2018 had 197 Parties (196 States and the European Union). The Convention’s ultimate objective is the ‘stabilisation […]