ACR at Winrock International founded in 1996 focuses on forestry & land use-pioneers science-based methodologies for forestry-based emissions reductions and removals covering activities like improved forest management, reforestation and conservation practices; ecosystem services-includes initiatives within natural-resource stewardship and ecosystem enhancing efforts that sequester carbon or prevent emissions; energy and industrial-Develops methodologies aimed at reducing greenhouse gas emissions in industrial processes and energy production/efficiency; and agriculture-through partnerships with USDA and Winrock's agriculture teams, ACR supports climate-smart agricultural practices, enabling certification and monetization of greenhouse gas certificates for U.S. commodity producers. ACR employs rigorous methodologies and registry services to drive high-integrity carbon crediting. https://acrcarbon.org/ 

ART is a global program focusing on large-scale REDD+ (forest conservation) credits. The first version of TREES was published in 2020 and version 2.0 approved in 2021. Primary focus sectors include; Reducing Deforestation & Degradation-Credits are issued for emission reductions achieved by slowing or halting deforestation and forest degradation, the foundational and most urgent REDD+ action. Removals via Reforestation and Restoration-TREES 2.0 introduced crediting for carbon removals through afforestation, reforestation, and the restoration of degraded lands, recognizing the role of rebuilding forest carbon stocks. Protection in High-Forest, Low-Deforestation (HFLD) Areas-Jurisdictions with high forest cover and historically low deforestation rates can receive credits both for ongoing emission reductions and for removals, an incentive to conserve intact forest systems. All are implemented at a jurisdictional scale with high-integrity safeguards and MRV protocols. https://www.artredd.org/trees/

BioCarbon Registry (BCR) is an independent GHG crediting program founded in 2018 based in Europe (Spain) with a global reach. It supports projects across energy, forestry, agriculture, biodiversity, and water through dedicated standards (GHG, Biodiversity, Water). All projects follow BCR’s methodologies focusing on measurable climate benefits and contributions to SDGs. Primary project types include AFOLU (forestation, mangrove restoration), renewable energy, transportation, waste management, Biodiversity and water co-benefits. Biocarbon uses a blockchain-based registry (Global Carbon Trace) for transparency. By 2023, BCR achieved ICROA endorsement and connected to the Climate Action Data Trust for data sharing. https://biocarbonstandard.com/en/ 

Carbon Standards International (CSI), headquartered in Switzerland, founded in 2021 as a collaboration between the EASY-CERT group AG and the Ithaka Institute develops standards for engineered carbon removal and biochar. CSI’s “Global C-Sink” standards create CINK credits for long-term stored carbon, with methodologies co-developed with the Ithaka Institute (a leading biochar research body. CSI employs digital MRV tools (e.g. a Global C-Sink digital platform) to streamline monitoring, and it emphasizes scientific rigor (partnerships with research institutes). In 2023, CSI merged with the International Biochar Initiative to unify global biochar standards, strengthening its protocols. By mid-2025, CSI had over 100 projects and achieved full ICROA endorsement. https://www.carbon-standards.com/en/home

CERCARBONO, founded in Colombia in 2016, is a voluntary carbon standard now active across 12+ countries. It issues credits under its “Voluntary Carbon Units” program using methodologies spanning renewable energy, energy efficiency, forestry (REDD+/afforestation), waste, and more. While global in scope, it has a strong Latin American presence and multilingual platform. Core methodologies adhere to ISO 14064 and emphasize environmental integrity. CERCARBONO is known for leveraging blockchain via Eco registry for a transparent project registry. As of 2023, it was among the top three global standards by volume, with rapid growth after ICROA endorsement. Unique innovations include a Circular Economy Standard (e.g. plastic waste crediting) and a forthcoming Biodiversity Credit Program – positioning CERCARBONO beyond carbon. https://www.cercarbono.com/

City Forest Credits is a U.S. focused nonprofit standard founded in 2015 dedicated to urban forestry projects. It certifies carbon offset projects in metropolitan areas (street tree plantings and forest preservation in cities). CFC uses custom protocols for urban tree planting (26-year crediting) and preservation (40- or 100-year commitments), accounting for carbon sequestration as well as quantified co-benefits (stormwater runoff reduction, air quality, energy savings). Its credits carry a “social impact” component benefiting urban communities, and the projects often partner with city governments and local nonprofits. CFC was endorsed by ICROA in 2023 and its credits are increasingly sought for local climate neutrality claims. Recent developments include new methodologies (e.g. riparian buffers), and the integration of CFC’s registry data into city sustainability plans, highlighting it as a model for localized climate action. https://www.cityforestcredits.org/

Climate Action Reserve is a prominent North American standard launched in 2008 originally founded by the State of California in 2001 (evolving from the California Climate Action Registry). It operates globally with a focus on the U.S. and Mexico, covering sectors like forestry (it pioneered the U.S. Forest Protocol), urban forestry, livestock methane, ODS destruction, landfill gas, and others. CAR credits are accepted in California’s compliance cap-and-trade (and can be converted to ARB offset credits), and it introduced innovative project types like ODS refrigerant destruction and mine methane capture. CAR also developed the Climate Forward program for ex-ante future mitigation credits. Recent updates include achieving ICVCM CCP-Eligibility in 2024 and updates to its Mexico Forest Protocol, as well as launching a digital platform for project documentation. Climate Action Reserve | Climate Action Reserve

The GCC, based in Qatar, is the first carbon standard from the MENA region to achieve global prominence. It supports projects worldwide, with many in Asia and the Middle East, covering renewable energy, energy efficiency, waste, and land-use (including REDD+ and cookstoves). GCC’s methodologies take cues from CDM and other best practices, adapted to emerging markets. Endorsed by ICROA in 2021, the GCC rapidly grew its pipeline – by 2024 it had nearly 1,000 projects in process (many transitioned from the CDM). GCC initially allowed certain pre-2020 renewable projects to earn credits, filling a market gap, and it provides upfront crediting for some projects to improve viability. It uses a blockchain-linked registry (via IHS Markit/Energy platforms) for transparency. Recent developments include GCC receiving approval from the ICAO for the CORSIA scheme (Phase 1) in late 2024, undergoing assessment for ICVCM’s program-level approval (one of the first in 2023 for its robust governance) and expanding into nature-based solutions (it opened its first NBS methodology consultation in 2025). https://globalcarboncouncil.com/

ICR is a newer global crediting program established in 2020 headquartered in Iceland. By late 2024, ICR had 121 projects listed across all continents, spanning nature-based projects and tech-based solutions. Core project types include forestry and land-use, renewable energy, and emerging removal technologies – with all methodologies built around ISO 14064 and supplemented by ICR’s own criteria to enhance efficiency and integrity. ICR emphasizes user-friendly digital infrastructure (it launched a modern project platform and API-enabled registry) and aims for rapid credit issuance while maintaining quality. It was fully endorsed by ICROA in January 2025, reflecting its solid governance. While still building a track record (first credits were issued in 2023), ICR has aligned itself with the Climate Action Data Trust and is actively seeking ICVCM approval. A notable recent development is ICR’s work on standardized “product carbon removal” credits (in partnership with Nordic firms) and its commitment to high transparency. https://www.carbonregistry.com/

Rainbow (formerly Riverse), established in 2021, is a 2024 ICROA endorsed carboncredit standard and registry tailored for engineered avoidance and removal projects. It stands out through its rigorous scientific approach, ISO 140642/aligned methodologies, and a fast certification process using primary field data plus thirdparty audits, typically concluding within three months. Its public documentation hub offers transparent, Science backed rules and procedures across modular methodologies from biochar and enhanced rock weathering to refurbished electronics and biobased construction materials. Recent developments include a mid2025 rebranding from “Riverse” to Rainbow, complete with a strategic collaboration with Crystalchain announced in July 2025 to enhance traceability in biochar CDR projects. Additionally, Recoal’s hydrothermal carbonization and subsurface storage methodology received full validation under Rainbow’s registry, marking a significant step for durable carbon removal in early 2025. https://rainbowstandard.io/

Plan Vivo is one of the longest-running carbon standards tracing its origins to 1994, dedicated to community-based forestry, agroforestry, and ecosystem projects. Operating mainly in the Global South, Plan Vivo’s projects (often smallholder-driven) generate Plan Vivo Certificates (PVCs) with strong co-benefit requirements for livelihoods and biodiversity. Key project types include native tree planting, agroforestry systems, soil conservation, and cookstove or water filter projects that have community ownership. Plan Vivo’s methodologies are tailored to local contexts (e.g. participatory carbon monitoring) and emphasize capacity-building for communities. The standard uses long-term trust funds to ensure payments to farmers over decades, and issues credits ex-ante (which buyers must retire as the sequestration is realized). Plan Vivo was endorsed by ICROA in 2022 and is recognized for “premium” community outcomes. Recent developments include Plan Vivo’s collaboration on a “Fair Trade Carbon” initiative and updates to incorporate the ICVCM’s Core Carbon Principles, as well as development of new methodologies for blue carbon and mangrove restoration. https://www.planvivo.org/

Puro.earth was founded in 2018 and launched its first CO₂ Removal Certificates (CORCs) by 2019. It earned endorsement from ICROA in March 2023 becoming the first durable carbon removal program to meet ICROA’s Code of Best Practice. It focuses specifically on industrial-scale carbon removal sectors—biochar, geologic storage, enhanced rock weathering and supports emerging methods through rigorous methodology development. Recent developments include publishing a major update to its 2025 Enhanced Rock Weathering methodology enhancing sampling, quantification, and uncertainty protocols after extensive public review and achieving CCPEligibility for version 4.2 of its General Rules from the ICVCM in December 2025. https://puro.earth/

The Social Carbon Standard (SCS), originally developed in Brazil by the Ecological Institute, was revitalized as an independent crediting program and endorsed by ICROA in 2023. It integrates a sustainable livelihoods framework into carbon accounting – assessing six social and environmental indicators to ensure projects improve community well-being. Social Carbon works globally, often complementing other standards or issuing its own credits. Primary project types include regenerative agriculture and soil carbon, forestry and REDD+ with community co-management, and small-scale energy projects (e.g. biodigesters, cookstoves) with strong local participation. Projects must implement a Social Carbon © monitoring plan to track co-benefit progress, and credits come with a “social stamp” guaranteeing robust stakeholder benefits. After re-launch, the standard introduced digitized processes (a new online portal for PDDs and monitoring) and updated NBS methodologies. Social Carbon is innovating by rewarding projects in new areas such as blue carbon algae removal and low-deforestation agriculture. https://www.socialcarbon.org/

Verra’s VCS Program is the largest voluntary carbon crediting program in the world. It operates globally across 125+ countries and supports all major project categories: REDD+ and AFOLU forestry, renewables and energy efficiency, waste and methane, industrial gases, and more. Its registry contains 3,400+ active projects that collectively have avoided or removed enormous volumes of CO₂. Verra offers complementary standards for co-benefits – the CCB Standards for climate, community & biodiversity and SD VISta for sustainable development – to tag VCUs with verified benefits. Recent developments include Verra’s work to align with the ICVCM’s Core Carbon Principles (multiple VCS methodologies were among the first to receive CCP approval in 2023–2024). Verra has also enhanced its digital MRV capabilities via pilots with tech firms. Despite facing scrutiny (e.g. critiques of certain forest projects leading to tighter additionality rules), Verra remains the benchmark for scale and breadth in the voluntary market, continually updating its governance (it formed a VCS Advisory Group in 2023) and increasing transparency to maintain stakeholder confidence. Website

Ormex (Mexico, est. 2023) is a startup-driven program targeting digital measurement and trading of project credits. It has a regional focus in Latin America and aims to simplify access for smaller project developers via an app-based registry (thus “.app”). Ormex received conditional ICROA endorsement in 2025, with a pipeline of community solar and forestry projects in Mesoamerica. https://www.ormex.app/

Proba.Earth (EU, est. 2021) is a niche standard specializing in scope 3 supply-chain credits, particularly in fertilizer and agri-food emissions. It quantifies N₂O emission reductions from optimized fertilizer use and issues credits that corporations can use for in setting. Proba achieved ICROA conditional endorsement in mid-2025. A unique aspect is its co-financing model: Proba links farmers implementing regenerative practices with corporates buying the resulting credits (blending offsetting and insetting). All three conditional programs are highly innovative but still small: each has only a few projects live and minimal issuances so far (below ICROA’s threshold of 10 projects/100k credits). https://proba.earth/