What is the voluntary carbon market

The voluntary carbon market (VCM) is a decentralized system where companies, governments, and individuals purchase carbon credits on a voluntary basis to compensate for their greenhouse gas emissions, without being legally required to do so. Each credit represents one metric ton of carbon dioxide equivalent (tCO2e) that has been reduced, removed, or avoided by a certified project. Unlike compliance markets, participation is driven by corporate climate commitments, investor pressure, or reputational strategy, not by regulation.

How it works in practice

A project developer, say a reforestation initiative in the Amazon basin, measures the carbon sequestered by newly planted trees over a defined crediting period. An independent third-party auditor validates the project methodology and verifies the actual emission reductions. Once verified, a registry (such as Verra’s VCS or Gold Standard) issues serialized carbon credits, each with a unique identifier. Those credits enter the market and can be sold directly to an end buyer or through brokers, exchanges, and retailers.

Consider a mid-size European airline that has pledged to offset 20% of its annual emissions by 2030. It contracts with a broker who sources credits from a portfolio of verified projects: cookstove distribution in Sub-Saharan Africa, mangrove restoration in Southeast Asia, and methane capture at a Brazilian landfill. The airline retires the purchased credits in the registry, meaning they are permanently removed from circulation and cannot be resold. The retirement is the act that converts a tradable financial instrument into an environmental claim.

Key registries and standards

The VCM does not have a single global regulator. Instead, credibility depends on the standard body that certifies each project. The most widely used include:

• Verra (Verified Carbon Standard, VCS), which holds the largest share of voluntary credit issuances globally.
• Gold Standard, originally established by WWF, with a strong focus on sustainable development co-benefits.
• American Carbon Registry (ACR) and Climate Action Reserve (CAR), both prominent in North American project types.
• The ICVCM (Integrity Council for the Voluntary Carbon Market), which published the Core Carbon Principles (CCPs) to set a quality threshold across all registries.

Credits that meet the Core Carbon Principles are tagged as CCP-eligible, giving buyers a baseline quality signal. However, CCP tagging does not replace project-level due diligence.

How the voluntary market applies in Brazil

Brazil is one of the largest sources of voluntary carbon credits in the world, driven by its vast tropical forests and the scale of land-use-related emissions. REDD+ projects (Reducing Emissions from Deforestation and Forest Degradation) in the Amazon and Cerrado biomes represent a significant share of supply.

In December 2024, Brazil enacted Law 15.042/2024, which established the Brazilian System for Trading Greenhouse Gas Emissions (SBCE). While the SBCE creates a regulated compliance market for high-emitting sectors, the same law formally recognized the voluntary market as a parallel, legitimate mechanism. The law assigned the federal government the role of regulating how voluntary credits interact with the national inventory to avoid double counting, a situation where the same emission reduction is claimed by both the project buyer and the Brazilian government under its Nationally Determined Contribution (NDC).

International professionals operating in Brazil should be aware that the regulatory framework is still being detailed through secondary regulation. The interministerial committee responsible for SBCE governance is expected to publish implementing decrees that will clarify reporting obligations for voluntary credit exports and nesting rules for jurisdictional REDD+ programs.

The most common mistake

The most frequent confusion is treating the voluntary market and the compliance market as interchangeable. They are not. In a compliance market (such as the EU Emissions Trading System), regulated entities must surrender allowances covering their verified emissions. The allowance price is shaped by a government-set cap on total emissions, and non-compliance carries legal penalties. In the voluntary market, there is no cap, no mandated surrender, and no penalty for not participating.

This distinction matters for pricing. Compliance allowances in mature systems have historically traded at significantly higher prices than most voluntary credits, because demand is guaranteed by law. Voluntary credit prices fluctuate based on buyer appetite, project type, vintage, co-benefits, and perceived quality. A nature-based removal credit with strong community co-benefits commands a different price than an older avoided-deforestation credit with contested additionality.

A second common error is assuming that buying a carbon credit automatically makes a company “carbon neutral.” Voluntary offsetting is only credible when paired with a measurable emission reduction strategy. Major frameworks, including the Science Based Targets initiative (SBTi), distinguish between compensation (using credits for residual emissions after deep decarbonization) and substitution (using credits instead of reducing emissions). The market has increasingly penalized the latter through reputational risk and greenwashing litigation.

Quality signals buyers should evaluate

Because the voluntary market lacks a single regulator, credit quality varies widely. Buyers conducting due diligence typically assess:

• Additionality: would the emission reduction have happened without the carbon finance?
• Permanence: is the stored carbon at risk of reversal (for example, through wildfire or illegal logging)?
• Leakage: does the project simply shift emissions to a neighboring area?
• Verification vintage: how recently was the project audited, and does the methodology reflect current scientific understanding?
• Double counting safeguards: does the host country have a corresponding adjustment mechanism to ensure the reduction is not also counted toward its NDC?

Without evaluating these factors, a buyer risks acquiring credits that do not represent real climate impact, undermining the purpose of the purchase and exposing the organization to scrutiny from regulators, investors, and civil society.

Primary sources: Verified Carbon Standard program (Verra, 2026); The Core Carbon Principles (ICVCM, 2023); Law 15,042 of 11 December 2024, creating the SBCE (Planalto, 2024); Corporate Net-Zero Standard v1.3.1 (Science Based Targets initiative, 2026).