COP26: a glossary of climate change terminology

Do you know the difference between scope one, two and three emissions? Is it better to be net zero or climate positive? Our COP26 glossary will help you understand the key terminology

Carbon Border Adjust Mechanism (CBAM)

CBAM is a tax on carbon-intensive products such as steel, aluminium, cement and fertiliser. It is part of the EU’s strategy to cut greenhouse gas emissions by at least 55% by 2030. The system is designed to level the playing field for European companies, meaning they remain competitive with firms from other countries that might not have such strict climate change targets.

Carbon capture and storage

The process of capturing, transporting and storing carbon from a large emitting source, such as a power plant or industrial facility, before it enters the atmosphere. The storage process, sometimes referred to as sequestration, often involves injecting the CO2 deep underground.

Carbon capture and utilisation

A process of collecting CO2 from one source and reusing it to produce a new product. Although this process doesn’t remove carbon from the atmosphere, by recycling the CO2 it can turn a carbon intensive process into a carbon neutral one.

Carbon credits

Carbon credits can be earned through offsetting, with each certified credit representing an emissions reduction equivalent to one metric tonne of CO2. These credits can then be purchased by a company or country to count towards their own carbon reduction goals. 

Carbon dioxide equivalent (CO2e)

A measurement used to group greenhouse gas emissions based on their global warming potential. Using this measurement helps to account for the impact of all emissions that contribute to the heating of the planet, such as methane and nitrous oxide, by calculating the amount of CO2 that would cause the same amount of warming. 

Carbon footprint

A carbon footprint can refer to the amount of carbon emitted by a company over a given period of time, the lifetime of a product or an individual’s actions — such as travelling by plane.

Carbon neutral

Becoming carbon neutral can be achieved by removing or eliminating the same amount of greenhouse gases emitted into the atmosphere. This is also sometimes referred to as being net zero.

Carbon offsetting

Carbon offsetting attempts to compensate for CO2 emissions by funding efforts to remove the equivalent of carbon from the atmosphere elsewhere. This often involves a third party which is paid to perform the decarbonising action in return for carbon credits. Common carbon offsets include planting trees or funding renewable energy projects. It is often used in areas of the economy that are difficult to decarbonise, such as air travel.

Carbon sequestration

The process of capturing and storing carbon from the atmosphere and storing it in a solid or liquid form (see carbon capture and storage). It is a method of reducing or reversing the impact of CO2 pollution and mitigating the effects of climate change and can be achieved through biological, chemical or technological means.

Climate positive

Climate positive goes beyond achieving net zero, meaning that the amount of carbon emissions being removed from the atmosphere exceeds the amount being produced.


COP26 is the 26th meeting of the Conference of the Parties, an annual gathering of the 197 party members of the United Nations Framework Convention on Climate Change (UNFCCC). This year’s event will be held at Glasgow’s Scottish Event Campus between 1 and 12 November, where climate experts, campaigners, policy makers and world leaders will debate how best to avoid the worst effects of climate change.


Short for ecological taxation, refers to a tax levied against activities which are harmful to the environment. It is designed to promote more environmentally friendly actions from businesses or individuals.


Commonly used in marketing or PR, greenwashing attempts to draw attention to a company’s sustainable actions and is often used to distract from its more environmentally destructive practices. 

Greenhouse gases

These are the group of gases that contribute to global warming through the greenhouse effect. The Kyoto protocol restricts the emissions of six greenhouse gases: carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons, perfluorocarbons and hexafluoride (SF6).

The Intergovernmental Panel on Climate Change (IPCC)

The Intergovernmental Panel on Climate Change (IPCC) is the United Nations body for providing scientific assessments of climate change. It was created to provide policymakers with regular updates on the implications and potential future risks of climate change and to put forward adaptation and mitigation options. The panel’s most recent report was described as a “code red for humanity” by the UN secretary-general. 

Kyoto protocol

Signed in 1997, the Kyoto Protocol is an international treaty that commits all parties to reduce global greenhouse gas emissions. Following on from the UN Framework Convention on Climate Change (UNFCCC), the Kyoto Protocol was the first to set legally-binding emissions reductions targets for individual countries and came into force from 2005. It was superseded by the Paris agreement in 2015.

Net zero

Net zero refers to the point at which the amount of carbon emitted into the atmosphere is the same as the amount of carbon being removed. 

Paris agreement

Another legally-binding international treaty which was agreed upon during the last COP conference in 2015. The Paris agreement set important goals to keep the rise in global temperatures below two degrees and to aim for less than 1.5 degrees. It also set financial targets for developed nations to help mitigate the impacts of climate change. 

Scope one emissions

Scope one accounts for the direct greenhouse gas emissions produced by an organisation, such as those created by burning fuel, driving combustion engine vehicles or released through industrial operations.

Scope two

Scope two covers indirect emissions, often associated with electricity or heating that has been purchased from an energy supplier.

Scope three

Scope three refers to all the greenhouse gas emissions created up and down the value chain of an organisation. For many businesses, this is where the majority of their emissions will be found. Upstream activities include emissions created during transportation and distribution, commuting, waste and any emissions from the production of goods and services purchased by the company, such as packaging. Downstream activities cover the emissions created through the use of its product and its end-of-life treatment, as well as those of any leased assets, franchises or investments.

United Nations Framework Convention on Climate Change (UNFCCC)

The United Nations Framework Convention on Climate Change is the United Nations entity tasked with supporting the global response to the threat of climate change. There are currently 197 party members of the convention, which also acts as the parent treaty to the Kyoto Protocol and Paris Agreement.

1.5 degrees

A 1.5 degree limit on the rise in the Earth’s average temperature, above pre-industrial levels, was enshrined in the Paris climate agreement and agreed upon by world leaders. Projections from the IPCC suggest that temperature rises above this amount would result in some of the worst effects of climate change becoming common place, putting billions of people at risk and causing irreversible damage to the environment.