Carbon terminology

Carbon terminology

The carbon world is full of jargon, acronyms, terms used interchangeably or even differently depending on who is using them! Here are some terms with their definitions as we use them.

Adaptation: Actions that contribution to the adaptation to climate change and its impacts. These an be social, environmental or economic in nature.

Additionality: Additionality is the principle that the carbon benefit that the project claims to deliver is additional to what would have occurred without the project interventions. For example, a project that claims to protect an already well-protected forest that is not subject to deforestation or degradation cannot claim to be additional. However, if it can be demonstrated that a forest is being degraded, and a project’s interventions will slow or halt this degradation, it is additional. This can be irrespective of legal protection or existing protected areas: often, protected areas are simply ‘paper parks’ with no real protection. A project that includes an existing area that is protected legally but not in reality can claim to be additional.  

Blue carbon: The carbon that is stored in the world’s oceans, coasts and wetlands. Three ecosystems are considered to be the core ‘blue carbon’ habitats: mangrove forests, seagrass meadows and saltmarshes. These ecosystems trap large volumes of carbon-rich organic matter not only in the plants themselves, but the soils beneath them. Because the soils are waterlogged, this carbon is locked away over much longer timescales than on land, where microorganisms can live in the soil and break down the organic matter for food, releasing the carbon. Soils that are waterlogged do not contain as many of these microorganisms, and so the carbon is stored for centuries to millennia in blue carbon ecosystems.

Carbon benefit: The carbon that a project claims to have sequestered (absorbed) or prevented in emissions. For example, a project that plants trees can claim the carbon that is sequestered by those trees as its ‘carbon benefit’.

Carbon credit: The unit in which carbon offsets are traded. One carbon credit is equivalent to one tonne of CO2 equivalent (tCO2e). These are generated by projects accredited to one of several carbon standards that approve the project’s methodology for calculating its carbon benefit (this can be achieved through planting trees, for example). They are bought by individuals and organisations to compensate for carbon that they have emitted.

Carbon footprint: The carbon emissions released as a result of the actions or an individual, organisation or any entity.

Carbon neutral: Carbon neutral is a claim made by company, event, product, or any other entity whose emissions can be claimed to have been eliminated or offset entirely, so that no net carbon is emitted as a result of its existence. There are many strategies by which ‘carbon neutrality’ can be claimed: all emissions could have been eliminated (ideal, but rarely feasible), all could have been offset (an environmentally and ethically weak strategy if there is any scope for emissions reductions), or a combination of the two (most frequently adopted, and often the most feasible pathway).

Carbon offset: A reduction in emissions, or sequestration (absorption) or atmospheric emissions, that is made to compensate for emissions made elsewhere. This is most frequently achieved by buying offsets from accredited projects, but it can also be achieved by implementing your own interventions such as planting a forest on your own land (this is sometimes referred to as ‘insetting’).

Carbon standard: A certification scheme involving rues, requirements and recommendations that a project must follow and abide by in order to achieve and maintain certification. A number of carbon standards exist, including the Plan Vivo Standard, VCS and The Gold Standard. Carbon standards vary in their requirements; for example, some are best suited to large-scale projects while others facilitate small-scale, community-based projects. However, all exist in order to maintain accountability, transparency and best practice among carbon trading projects.

Carbon storage: The storing of carbon – in biological terms, this is stored as organic matter such as the woody biomass of trees or in peat formed over thousands of years as plants die).

Climate crisis (also climate change, climate breakdown, climate emergency, climate chaos): Anthropogenic (human-caused) emissions have led to rapidly increasing levels of CO2 in the atmosphere that are having a catastrophic effect on the warming of the climate. This was earlier known as “global warming”, although it is recognised that (a) temperatures are not rising uniformly across the world and (b) in some areas, the most noticeable and damaging effects of the climate crisis are not just in temperature but in changing seasons, rainfall and storms. The climate crisis (also breakdown, emergency, chaos) terminology came into use around 2018 in recognition that “climate change” did not adequately convey the severe threat that is posed to the world by a warming climate.

CO2 : Carbon dioxide is the most prevalent greenhouse gas in the atmosphere. While some is needed for plants to photosynthesise, human activities have been emitting so much CO2 into the atmosphere that it is driving a change in the climate and with it, the climate crisis.

Greenhouse Gas: Gases including carbon dioxide, methane and nitrous oxide that, when present in the atmosphere, contribute to a warming of the earth’s surface and atmosphere. Without them, the average temperature on Earth would be -20; however, the high concentrations caused by anthropogenic (human) emissions, Earth is warming alarmingly and devastatingly fast.

Leakage: Leakage is the unintended displacement of harmful activities from the project area to another area, resulting in no net benefit from the project. For example, in forestry, excluding the cutting of timber without measures to compensate for lost firewood may mean that people simply go elsewhere to cut wood. Projects must take action to ensure that this does not take place – for example, our projects maintain sustainable woodlots to provide timber for local people.

Legacy carbon: Historic carbon emissions, emitted before current carbon accounting periods such as the current year. See Microsoft’s commitment to compensate for all of the carbon that the company has ever emitted!

Mangroves: Forests that grow in waterlogged, saline environments such as coasts and estuaries. They consist of 80 species worldwide that have adapted towithstand high levels of salinity. Mangroves grow in tropical to sub-tropical regions worldwide, and are globally threatened by coastal development, pollution, aquaculture and cutting for timber.

Mitigation: Actions that reduce the levels of greenhouse gases in the atmosphere, either by reducing them at their source (such as transitioning from oil and gas to renewable energy) or creating or enhancing sinks of carbon, such as through reforestation or protecting threatened wetlands.

Nationally Determined Contributions (NDCs): Commitments made by nations that will demonstrate how they will met their mitigation and adaptation goals under the Paris Agreement. NDCs are revised and submitted every 5 years (the latest round were submitted in 2020).

Net Zero: Very similar to (and often used interchangeably with) carbon neutrality, but includes all greenhouse gases (GHGs) including methane, nitrous oxide and hydroflourocarbons.

Paris Agreement: The landmark agreement, signed by 190 nations, that legally binds nations into plans for climate change mitigation and adaptation, and the financing of these activities.

Permanence: Permanence is the principle that a project can be assumed to maintain its carbon benefit over ‘permanent’ (generally accepted as 100+ years) timescales.While this is impossible to guarantee in the present day, a number of means can be used to assess permanence including how well the ecosystem naturally stores carbon, and what work will be undertaken by the project to address drivers of degradation as well as actively excluding them during the project lifespan.

Project Design Document (PDD): A comprehensive document detailing how a project will operate. In carbon trading, these documents are approved and held by the relevant carbon standard.

Risk buffer: A proportion of credits that are deducted from a project’s calculated total carbon benefit to precautionarily account for ‘non-permanence’, or the risk that that carbon might be lost earlier than is expected. This could occur because of reasons outside of a project’s control such as storm damage, drought or wildfires. A risk buffer is therefore a conservative and precautionary means of minimising the risk of selling carbon that will then be re-released into the atmosphere.

Seagrass: Seagrasses are the only flowering plants (orangiosperms) that live in saline (salty) environments. They grow in intertidal to sub-tidal regions in temperate, sub-tropical and tropical regions worldwide. Seagrasses grow in meadows that are vulnerable to destruction by physical impacts from boats, anchors and fishing gear, pollution and coastal development.

Sequestration: The absorption of carbon from the atmosphere. This can be achieved through biological processes (i.e., natural carbon sinks such as forests) or geologic (i.e., Carbon Capture and Storage).

Soil carbon: The carbon that is stored in soil, most notably below forests and other vegetation that traps organic matter among their roots. Although soils are much less charismatic than the forests themselves, the carbon that is stored within the soils of blue carbon ecosystems can be many times higher, and be locked away for much longer, than is stored in the plants themselves.

tCO2e (tonnes of carbon dioxide equivalent): Carbon dioxide (CO2) is one of several greenhouse gases. It is the most prevalent greenhouse gas, but it not the most potent. Methane, for example, has a warming impact on the atmosphere that is 84 times as strong as CO2 in a 20-year timeframe; however, it breaks down much quicker than CO2, so over a 100-year timeframe it has an impact of around 28 times that of CO2. To account for these differences between the greenhouse gases, carbon credit units are standardised into tCO2e, or ‘tonnes of CO2 equivalent’. For example, over 100 years, a tonne of methane would be converted to 28 tCO2e.

Unavoidable carbon: Carbon emissions should be reduced before they are offset. Carbon offsets should not be used as an alternative to offsetting; reducing your emissions by 100t is better than having to compensate for 100t of emissions that could have been avoided. ‘Unavoidable’ emissions are the emissions of a person or organisation after they have made all feasible reductions. What this means will vary from case to case, and financial, social, work and other factors may need to be considered. For example, a flight to visit close family living overseas provides considerable social and psychological benefit. Domestic emissions may be unfeasible to reduce or eliminate because of the high cost of switching to renewable sources, or the environmental impact of replacing existing, working systems.  

Voluntary and compliance carbon markets: The carbon market – that is, all of the carbon trading that exists in the world – is broadly split into the voluntary and compliance markets. The compliance carbon market (dominated by the Clean development Mechanism, or CDM) is used by large, high-emitting industries who are required by law to reduce their carbon emissions, while the voluntary carbon market is used by individuals and businesses who choose to buy offsets. The two markets differ in the projects that they host: the compliance market is dominated by energy projects such as financing renewable energy solutions, whilst the voluntary market is a combination of energy and nature-based solutions such as forestry. Projects on the voluntary carbon market are typically smaller, involve communities in management and governance to a greater extent, and typically command a higher price per tonne of carbon; this reflects higher implementation costs of running small-scale and community-based projects.

Wetlands: Areas of land that are covered by water either seasonally or permanently. This could include vegetated coastal habitats such as mangrove forests, or areas inland such as peat bogs. Wetlands are important stores of carbon and support rich biodiversity.

Zero emissions, or actual zero: The state of a company, event, product, or any other entity whose emissions can be claimed to have been eliminated entirely. This cannot include emissions that have been offset. This is ideal but rare, particularly in public businesses in which a number of factors such as external investments and utilities contracts are involved.