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The voluntary carbon markets ecosystem, simplified

April 26, 2023

The Voluntary Carbon Markets (VCMs) and its key players can be a complex landscape to navigate. We have created this simple cheat sheet to break down the different groups and actors* that make up all sides of this fast-growing market. 

*While we have tried to include all of the main groups working in the VCMs this is not a complete list.

Standards & Registries


Verra is a non-profit organization that was founded in 2007 and they manage the world’s largest VCM standard program, the Verified Carbon Standard (VCS) program. The VCS program is currently the largest issuer of carbon credits. 

The Gold Standard (GS)

Gold Standard is a non-profit organization that was established in 2003 by The World Wide Fund for Nature (WWF) and other international NGOs as a voluntary carbon offset program. 

American Carbon Registry (ACR)

The American Carbon Registry, a nonprofit enterprise of Winrock International, was founded in 1996 as the first private voluntary greenhouse gas registry in the world. 

Climate Action Reserve (CAR)

The Climate Action Reserve was launched in 2008. It is a US-based voluntary offsets program whose projects are implemented within North America. 

Plan Vivo 

The Plan Vivo standard is a relatively small program but the largest standard for smallholder and community-forestry projects. The Plan Vivo foundation was established in 2009.


South Pole

South Pole was founded in 2006 in Zurich. They are a leading project developer and provider of global climate action solutions. 


Founded in 2017, Everland represents a portfolio of high-impact, forest conservation (REDD+) projects that protect wildlife and enhance the well-being of forest communities. 

Anew (formerly Bluesource)

Anew emerged from the February 2022 combination of industry leaders Element Markets and Bluesource. Bluesource was the largest carbon credit developer in North America and Element Markets was a leading renewable natural gas marketing and environmental commodities company.

Intermediaries & Marketplaces


Founded in 2018, Pachama is an AI-powered marketplace for nature-based carbon removal, avoidance and REDD+ credits.  

Salesforce Net Zero Marketplace

San Francisco-based Salesforce introduced its carbon credit marketplace in September 2022. With built in third-party ratings from agencies such as Sylvera and Calyx Global, the market is the first of its kind. It offers all project types and currently only sells carbon credits to U.S based organizations.  


NCX was founded in 2010 and connects American forest landowners with carbon credit buyers. It specializes in nature-based Improved Forest Management (IFM) carbon projects.  


Ecologi was founded in 2018 by a group of environmentalists in Bristol, UK. It is an online platform that enables individuals and businesses to remove their carbon footprint through a subscription-based service that funds forest projects and contributes to other carbon-reducing activities.  


Goodcarbon provides a digital investment and trading platform based in Germany. They allow for buyers to invest in nature-based solution projects.


Patch enables companies to embed carbon credit purchases into their products via an API. They offer a wide range of carbon removal projects across nature-based and frontier technology.


Xpansiv CBL

Formed in 2019 through the merger of CBL (founded 2009) and Xpansiv (founded 2016), Xpansiv CBL is the global market infrastructure for registering, managing, trading, settling, retiring, analyzing, and reporting an infinite array of data-driven environmental commodities.

Climate Impact X (CIX)

Climate Impact X (CIX) is a global marketplace and exchange for quality carbon credits based in Singapore. Jointly established by DBS Bank, Singapore Exchange (SGX Group), Standard Chartered and Temasek, their goal is to build trust in existing credits, bring new credit types to market and help scale the next wave of impactful solutions. 

AirCarbon Exchange (ACX)

Air Carbon Exchange (ACX) is a Global Carbon Exchange using distributed ledger technology on a traditional trading architecture. It leverages blockchain architecture to create securitized carbon credits.

Ratings providers


Founded in 2020, Sylvera is a carbon data platform that offers a suite of tools for real climate impact. Sylvera creates proprietary peer-reviewed frameworks for each carbon project category, which underpin project-level ratings. Sylvera also has an analytics tool called Carbon Credit Analytics (CCA) which was launched in 2023 to help net zero leaders benchmark their carbon investments against their industry and other companies and to help financial institutions understand the risk exposure of their portfolios.


BeZero was founded in 2020 and provides ratings, risk and data tools that improve information accessibility and decision-making. BeZero uses its generalized Rating Analytical Framework along with sector-specific Risk Assessments. BeZero is the only ratings agency to make its topline ratings freely available, and paying clients have access to full project assessments.

Calyx Global

Founded in 2021, US-based Calyx Global helps businesses choose carbon credits with comprehensive independent carbon credit ratings. Calyx Global offers two services: Calyx Ratings Service, a subscription to a website where one can see all ratings, and Calyx Project Reports which offers detailed information about each rating.


Founded in 2019 in Austin, Texas, Renoster operates as a deep transparency software developer. The company's software is the Mercury Rubric which helps in rating forest carbon projects and serves large enterprise organizations. Renoster only rates nature-based projects at this time. 

Learn more about the role of carbon credit rating agencies here.

Supply-side integrity initiatives

Integrity Council for the VCM (IC-VCM)

The IC-VCM is the leading initiative focused on the quality and integrity of credits, considering factors such as additionality, permanence, leakage and safeguards. Assessment is at the level of both standards and credit types, and is a binary pass/fail system (with additional labels suggested in the draft such as removals or avoidance). 

The IC-VCM has a list of Core Carbon Principles (CCPs) that are a global benchmark for high-integrity carbon credits that set rigorous thresholds on disclosure and sustainable development. 

Carbon credit quality initiative (CCQI)

Founded by the Environmental Defense Fund, World Wildlife Fund (WWF-US) and Oeko-Institut, this free online tool assesses the quality of crediting methodologies. In comparison to IC-VCM, there is a particular focus on environmental and social impacts, and the ratings are 1-5 across the 7 'quality objectives'  considered. Currently few methodologies are covered, but more are planned soon.

International carbon reduction and offset alliance (ICROA)

ICROA was the first body focused on market quality and integrity—it only assesses at standard-level. Both governmental and voluntary standards are assessed against the code, with only the most rigorous being endorsed - currently only 4 government standards and 5 voluntary standards are fully endorsed (also, 2 are conditionally approved). This body is housed within the International Emissions Trading Association (IETA).

Buy-side integrity initiatives

Voluntary Carbon Market Integrity Initiative (VCMI)

Launched in 2021, the VCMI looks at the claims made by carbon credit buyers. Draft guidance released last year suggests that in order to make a VCMI-approved climate claim, buyers will have to first set a science-based net zero target and follow the mitigation hierarchy (i.e. reduce their own emissions first). The level of ambition they achieve will then result in either a gold, silver or bronze accreditation. Full guidance is expected later this year.

The Oxford Offsetting Principles  

Launched in 2020, the Oxford Offsetting Principles focus on how best to align offsetting with net zero targets, focusing on following the mitigation hierarchy. They focus on four main elements: 

  • Prioritize reduction of your own emissions first, ensure the environmental integrity of offsets you use and disclose how those offsets operate
  • Shift offsetting towards options that directly remove carbon from the atmosphere
  • Shift offsetting towards long-lived storage, which removes carbon from the atmosphere permanently or almost permanently
  • Support development of a market for net-zero-aligned offsets

Wider sustainability initiatives that touch on VCMs

Science-based targets initiative (SBTi)

Science-based targets are emissions reduction targets designed to align with the latest climate science from the Intergovernmental Panel on Climate Change (IPCC) and the goals of the Paris Agreement. It was formed in 2015 and is the leading corporate net zero standard. The SBTi is a partnership between the CDP (formerly the Carbon Disclosure Project), the United Nations Global Compact, World Resources Institute (WRI) and the World Wide Fund for Nature (WWF).

Its goal is to assist corporations with setting science-based targets by providing a rigorous, science-based framework within which to set targets and then report against them. To date, over 1000 of the world’s largest companies have set SBTs through the SBTi, with more doing so every month. They provide guidance on the use of carbon credits in science-based net zero targets - more details on this are expected later this year with the full beyond value chain mitigation guidance

UN High-Level Expert Group (HLEG)

Launched in 2022, the report lays out 10 recommendations for ‘integrity, clarity, and accountability to net zero commitments.’ Short, medium and long-term science-based targets are required, all CapEx and investments must also be net zero-aligned, and reporting and disclosures must be done using a standardized format that feeds into a UNFCCC portal. It goes further beyond SBTi by looking at the bigger picture: investment in a just transition, regulation across areas including pledges and transition plans, and external policy and engagement efforts including membership in trade associations. 

Their latest report “Integrity matters: Net Zero Commitments by businesses, financial institutions, cities, and regions” details the use of carbon credits in the VCMs stating “High integrity carbon credits in voluntary markets should be used for beyond value chain mitigation”

Taskforce On Climate-Related Financial Disclosures (TCFD)

The Financial Stability Board (FSB) created the TCFD to develop recommendations on the types of information that companies should disclose to support investors, lenders and insurance underwriters in appropriately assessing and pricing risks related to climate change. It has been adopted by the G7 countries, New Zealand, Switzerland and more. 11 disclosure recommendations span four different areas: governance, strategy, risk management, and metrics and targets.

It does not directly require any disclosures about carbon credits but accelerated the movement towards requiring climate-related disclosures which is now expanding to include credit use.

Carbon Disclosures Project (CDP)

Formed in 2002, CDP runs the global environmental disclosure system. They support organizations in making their environmental impact transparent to stakeholders improving  their understanding of how they can reduce their impact and act as environmental leaders. CDP has the world’s largest, most comprehensive set of environmental data, and is utilized by capital markets and purchasing organizations to make informed decisions, reward high-performing companies and drive action. CDP disclosure is fully TCFD-aligned and also includes additional optional disclosures including carbon credit retirement and details about those credits. 

UN Race to Zero

Race To Zero is the largest-ever alliance committed to achieving net zero carbon emissions by 2050, at the latest. It mobilizes a coalition of thousands of organizations with net zero commitments, including corporate, non-state and public sector actors. Like SBTi, Race to Zero provides guidance on the appropriate use of credits in net zero transition plans.

Industry groups

International Emissions Trading Association (IETA) 

The International Emissions Trading Association (IETA) is a non-profit business organization created in 1999 to establish a functional international framework for trading in greenhouse gas emission reductions. The principal objective of IETA is to serve as a forum for the exchange of ideas, information and experience relating to international greenhouse gas emissions trading. 

Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA)

CORSIA brings together all member states of the International Civil Aviation Organization (ICAO) to address emissions from international aviation, which are outside of the scope of national targets. As CORSIA comes into operation it is expected to drive significant demand for carbon credits. CORSIA is also of interest to many credit buyers as they have identified a list of eligible credits, which is seen as a marker of quality by some.

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About the author
Marketing Coordinator

Eadaoin has a degree in Government and Political Science from University College Cork. She has experience working in the non-profit sector addressing inequality and environmental issues in Ireland, and now works on the marketing team at Sylvera.