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).

ACRA - Accounting and Corporate Regulatory Authority Singapore's regulator of company registration, financial reporting, auditors and business service providers, also responsible for developing the accounting profession and setting accounting standards for companies, charities, cooperatives and societies.

B Corp - B Corporation – 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.

CO2e, CO2eq or CO2-equivalents - Carbon Dioxide Equivalent – 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).

CSRD - Corporate Sustainability Reporting Directive – A modernised and strengthened European directive ruling the reporting of social and environmental information. Companies subject to the CSRD will be required to report in accordance with ESRS (European Sustainability Reporting Standards) from the 2024 financial year.

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.

Eco-friendly, Environmentally-friendly, Earth-friendly, Green – 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.

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.

EFRAG - European Financial Reporting Advisory Group A private association whose aim is to ensure that European views on accounting standards are given due consideration in the development of international standards, and which provides advice to the European Commission.

ESG - Environmental, Social and Governance 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.

ESRS - European Sustainability Reporting Standards A set of mandatory sustainability reporting standards in the EU. The ESRS are an integral part of the European Parliament and Council’s Corporate Sustainability Reporting Directive (CSRD). The first release of the ESRS in August 2023 comprises 12 standards, to be followed by sector-specific and SME-appropriate standards in the coming years.

Externality A cost (negative externality) or benefit (positive externality) caused by an economic agent to a third party.

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.

GHG - Greenhouse Gases – 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.

GRI - Global Reporting Initiative – A set of best practices and reporting guidelines for sustainable development covering over 900 sustainability topics and addressing different levels of economic, social and environmental performance. It is currently the most widely used environmental reporting framework.

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.

Internal Carbon Price –  A monetary value assigned per tonne of CO2 equivalent that allows a company to account for its impact on climate change and to incorporate these costs into business and investment decisions.

IPCC - Intergovernmental Panel on Climate Change – United Nations body (a group of experts) for assessing the science related to climate change. IPCC issues assessment reports about the state of scientific, technical and socio-economic knowledge on climate change, its impacts and future risks, and options for reducing the rate of climate change.

ISSB - International Sustainability Standards Board – An independent standard-setting body within the IFRS Foundation, the ISSB aims to provide a global baseline of sustainability disclosures for global capital markets and comparability across jurisdictions. The ISSB builds on the work of market-led, investor-focused reporting initiatives, including the Climate Disclosure Standards Board (CDSB), the Task Force for Climate-related Financial Disclosures (TCFD), the Value Reporting Foundation's Integrated Reporting Framework and the industry-based SASB standards, as well as the World Economic Forum's Stakeholder Capitalism Metrics.

<IR> - Integrated Reporting –  A reporting framework aiming at focusing the corporate communication on value creation, preservation or erosion. Since August 2022, the Integrated Reporting framework has been under the responsibility of the ISSB.

LCA - Life Cycle Assessment –  A systematic analysis of the environmental impact throughout the life cycle of a product / material / process. It is used as a decision-making tool to support sustainability initiatives.

LEED - Leadership in Energy and Environmental Design –  developed by the United States Green Building Council (USGBC), it is a globally recognised green building rating system.

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.

NDC - Nationally Determined Contribution – 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.

RCP - Representative Concentration Pathway – A greenhouse gas concentration (not emissions) trajectory adopted by the IPCC.

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.

SASB - Sustainability Accounting Standards Board – A set of standards identifying sustainability-related risks and opportunities, disclosure topics and metrics, including 77 industry-specific KPIs, for investor-led reporting. Since August 2022, SASB has been under the responsibility of the ISSB.

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.

SDGs - Sustainable Development Goals – 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”.

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).

SRI - Socially Responsible Investment, 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.

SSP - Shared Socioeconomic Pathways – Climate change scenarios of projected socioeconomic global changes up to 2100 as defined in the IPCC 6th Assessment Report on climate change (2021).

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.

Sustainability Reporting Framework – a set of guidelines, definitions and tools to guide companies on how to structure the information. The most well-known are CDP, GRI, SASB, TCFD, <IR>, all with a different focus. They are complementary to the sustainability standards.

Sustainability Reporting Standards – a set of detailed requirements, including metrics, defining the content of the topics to be reported. They are complementary to the sustainability frameworks. They can be used as a basis for voluntary (e.g. GRI) or mandatory (e.g ESRS) disclosure purposes.

TBL - Triple Bottom Line – 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.

TCFD - Task force on Climate-related Financial Disclosure – A set of reporting recommendations aimed at monitoring and reducing climate change risks. The TCFD methodology incorporates climate change into companies’ business plans by integrating strategy and scenario analysis with financial risks. Originated by the G20 Financial Stability Board, the TCFD is a mandatory disclosure standard for large companies registered in the UK.

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.