The purpose of this glossary is to provide brief definitions of the main terms used in sustainability, so you get familiar with those notions and understand the differences and similarities between them. 

However, for many concepts in the sustainability field, there is no commonly accepted definition at international level. Therefore, the same concept can have dozens of similar or contradictory definitions. For more information, please refer to our pages that are related to a specific subject or to our references. 

3Rs – refers to the three words "Reduce, Reuse, Recycle". Those three words refer to the hierarchy of actions to undertake for better resources management.  In Singapore, it is used as a communication tool towards individuals and companies to promote better waste management practices. You can also find more "R" to add on: Refuse, Repair, Repurpose, Rethink, Rot…
When you do a Zero Waste Audit, the "R" to consider are: Reduce, Redesign, Reuse, Recycle, Re-earth (=Rot).

B Corporation (B Corp) – Created by the non profit B Lab organisation, the B Corporation movement aims to certify companies as Certified B Corporation (B Corp) through the B Impact Assessment process which takes into account the company’s whole social and environmental performance.

Carbon Credit – A “carbon credit” (also known as a “carbon offset ”) is an electronic and serialized unit that represents one ton of CO2 equivalent that is reduced, avoided, or sequestered from projects applying an approved carbon credit methodology.

Carbon dioxide equivalent (CO2e, CO2eq or CO2-equivalents) – is used to express different greenhouse gases emissions in a common unit, by multiplying the quantity of each GHG emission with its GWP (global warming potential). GWP estimates how much heat a GHG absorbs within a specific time horizon, compared to the heat absorbed by CO2.

Carbon Footprint – measures the total amount of Greenhouse Gases (GHG), including carbon dioxide and methane produced by individuals, organizations or products.

Carbon neutral or Carbon neutrality – is a state in which the amount of greenhouse gases released into the atmosphere is balanced by an equivalent amount of greenhouse gases removed or reduced. Carbon neutrality can be achieved by balancing or “offsetting” the greenhouse gases produced with carbon credits (avoidance, reduction or removal projects).

Circular Economy – is a new economical model as an alternative to the traditional linear model (take, make, use, dispose). It functions in a closed-loop system: make, use, reuse, remake, recycle, make. According to Ellen Macarthur Foundation (EMF), the main promoter of circular economy, this model is based on three principles: “design out waste and pollution, keep products and materials in use, regenerate natural systems." More details here.

Climate change – refers to long-term change of climate characteristics, caused by human activities (GHG emissions) which adds to the natural climate variability (natural internal variability, solar cycles, volcanic eruptions).

Decarbonisation – Literally, the reduction of carbon. More specifically, the term refers to the conversion of the economic system or individual carbon emitting entity converting to reduce the carbon intensity of its (direct or value chain) emissions over time.

Double counting– is a situation in which a single greenhouse gas emission reduction or removal is counted more than once towards achieving climate change mitigation.

Ecolabel – label issued by an organization, which certifies that a product or service meets a set of requirements. Those requirements may cover one or several environmental aspects of a product or service. Ecolabels aims to champion better products and facilitate the decisionmaking process of the consumer (individual or business). Ecolabels in Singapore.

Environmental, Social and Governance (ESG) factors – are a term used by asset managers and investors to evaluate corporate sustainability performance. For instance, environmental criteria consider GreenHouse Gas (GHG) emissions, biodiversity, waste management... Social criteria looks into employees training, employment ethics, fair wages... While Governance is about corruption, internal controls, etc.

Green, eco-friendly, environmentally-friendly, earth-friendly – refer to products, services or practices that claim reduced, minimal or no harm for the environment. Note that none of these words are defined by national or international standards. As a result, they are open to interpretation by consumers and businesses, hence might sometimes fall into the Greenwashing category.

Green Bonds – are fixed-income financial instruments (bonds) where the proceeds are to be used for environmental or climate projects. The Green Bonds Principles issued by the International Capital Market Association (ICMA) “are voluntary process guidelines that recommend transparency and disclosure and promote integrity in the development of the Green Bond market by clarifying the approach for issuance of a Green Bond.” Read more.

Other environmental or sustainability focused financial instruments: sustainability linked bonds, social bonds, green loans, sustainability linked loans.

Greenhouse gases (GHG) – natural and anthropogenic gases in the atmosphere that trap Sun’s heat, causing the greenhouse effect. When referring to reduce GHG emissions, it’s generally about the GHG of the Kyoto Protocol: carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O) and fluorinated gases (hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulphur hexafluoride (SF6)).

Greenwashing – is a marketing process used by an organization with the aim of creating a misleading image of environmental responsibility. Learn how to identify Greenwashing.

Hazardous Waste – is waste that possesses any of the characteristics contained in Annex III of the Basel Convention, or that is considered to be hazardous by national legislation. It refers to waste with properties that make it dangerous or capable of having harmful effects on the environment or human health [source].

Impact – refers to the impact the organization has or could have on the economy, environment, and people, including their human rights, which in turn can indicate its contribution (negative or positive) to sustainable development.

Materiality – is the principle of identifying and reporting on the most relevant sustainability or ESG factors (see above) regarding the company’s business model, strategy and stakeholders. The SASB materiality map per industry is a good start.

Nationally Determined Contribution (NDC) – The Paris Agreement requires participating countries to submit NDCs, which outline both their domestic emissions reduction goals and measures that each country will take to achieve them.

Net Zero – refers to the balance between the amount of greenhouse gas (GHG) that's produced and the amount that's removed from the atmosphere. It can be achieved through a combination of emission reduction and emission removal.

Rebound Effect – unintended overconsumption effect or over polluting effect induced by a choice taken in order to green a process. For example, if you wish to change your thermic car for an electric car, not taking into account your thermic car own lifetime may have a rebound effect since it implies 2 cars production carbon footprint not compensated by the lower carbon footprint of the electric car when driven….

REC - Renewable Energy Certificate – is a market-based instrument used to track the production of electricity from a qualifying renewable energy source such as solar, hydro or wind. One REC represents one megawatt hour (MWh) of electricity generated from a renewable energy source and delivered to the grid.

Renewable energy – refers to energy generated from natural resources that can be replenished through ecological cycles or agricultural processes. Examples: biomass, geothermal, hydro, solar, and wind.

Renewable material – is a material that is derived from natural resources that can be replenished through ecological cycles or agricultural processes.

Science Based Targets – defined by The Science Based Targets initiative (SBTi), a partnership between CDP, United Nations Global Compact, the World Resources Institute (WRI) and WWF. SBTi provides companies with a clearly-defined path to reduce emissions in line with the Paris Agreement goals. 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.

Scope 1, 2 and 3 emissions – refer to the three categories of GHG emissions (see above) of a company defined by the GHG Protocol.

  • Scope 1 - direct GHG emissions*: fuel combustion (petroleum, gas, coal), company owned vehicles (diesel, petrol), fugitive emissions
  • Scope 2 - indirect GHG emissions** generated by the purchase of energy (electricity, heat, steam)
  • Scope 3 - all other indirect GHG emissions** including production of purchased materials, product use, outsourced activities, contractor owned vehicles, waste disposal, employee business travels.

*Direct GHG emissions - emissions from sources that are owned or controlled by the company.

**Indirect GHG emissions - emissions that are a consequence of the operations of the reporting company but occur at sources owned or controlled by another company.

Severity (of an impact) – The severity of an actual or potential negative impact is determined by its scale (i.e., how grave the impact is), scope (i.e., how widespread the impact is), and irremediable character (how hard it is to counteract or make good the resulting harm).

Socially Responsible Investment (SRI), also known as sustainable investing or social investment – is an investment strategy which seeks to consider both financial return and Environmental, Social and Governance (ESG) criteria. More info here.

Stakeholder – a party that has an interest or concern in an organization and can either affect or be affected by it. Stakeholders can be internal or external, a person or a group, including investors, employees, customers, suppliers, communities, governments, NGOs, etc.

Sustainable development and Sustainability – Sustainable development aims for long-term stability of human societies. For that, the goal is to find balance between environmental, social and economic aspects, also known as the 3 three pillars of sustainability.

Sustainable development and sustainability are similar terms and often seem interchangeable. However, sustainability tends to be seen as a long-term goal where the sustainable is achieved, while sustainable development is the way to achieve it.

Sustainable Development Goals (SDGs) – the 17 Global Goals were adopted by all United Nations Member States in 2015 as “a universal call to action to end poverty, protect the planet and ensure that all people enjoy peace and prosperity by 2030”.

Triple Bottom Line (TBL) – is a concept that consists of three elements: profit, people, planet. Instead of the classical one bottom line – the profit, TBL takes into account social and environmental issues into measuring corporate performance.

Voluntary market – A market for carbon credits that are purchased voluntarily (i.e., not for emissions compliance purposes).

Zero Waste – is a set of principles focused on waste prevention. According to the Zero Waste International Alliance (ZWIA), the main promoter of Zero Waste, it’s “the conservation of all resources by means of responsible production, consumption, reuse, and recovery of products, packaging, and materials without burning and with no discharges to land, water, or air that threaten the environment or human health.”

Zero Waste and Circular Economy – rely on the same basic principles and aim for the same results which are a sustainable use of resources as well as a sustainable and inclusive society.