The main accreditation schemes for carbon offsetting

Carbon offsetting allows organisations and individuals to invest in projects that reduce or remove carbon dioxide from the atmosphere, compensating for their own emissions. 

However, for these offsets to be effective and trustworthy, they must meet strict standards to ensure they truly benefit the environment. This is where carbon offset accreditation schemes come into play. In this lesson we’ll explain what these schemes are and what their history is. So let’s get started.

What Are Carbon Offset Accreditation Schemes?

Accreditation schemes are designed to ensure that carbon offset projects adhere to a rigorous set of standards. They verify that the projects are real, additional, measurable, permanent, and verified—the five key principles that underpin a legitimate carbon offset. 

These schemes also promote transparency and credibility by certifying that offset projects genuinely reduce or remove carbon emissions.

Projects seeking accreditation under these schemes must undergo a thorough assessment process to prove they meet the required criteria. After this, they are verified by an independent third party, which ensures that emissions reductions are calculated accurately and are not double-counted.

Why Accreditation Schemes Matter for Carbon Offsetting

Without proper accreditation, carbon offset projects run the risk of greenwashing—the practice of giving a misleading impression about environmental benefits. 

Accredited schemes help prevent this by offering third-party verification and ongoing monitoring, making sure that offset claims are backed by evidence.

Accredited schemes are especially important in ensuring that offset projects meet key criteria for what makes a good offset. In a previous article, we highlighted these essential criteria:

• Real: The carbon savings must actually happen.
• Additional: The project must go beyond business-as-usual and not something that would have occurred without offset funding.
• Measurable: The carbon savings must be quantifiable using reliable methods.
• Permanent: Carbon sequestration must be long-lasting and irreversible.
• Verified: The project must be regularly monitored and audited to ensure the carbon savings are legitimate.

How Accreditation Works

Accreditation schemes set a standard for carbon offset projects, providing a framework for what constitutes a credible carbon offset. Project developers apply for accreditation by demonstrating that their initiatives meet the standards set by the scheme. Once approved, independent third-party verifiers periodically assess the project to ensure compliance.

There are several major accreditation schemes, with some being international and others UK-based. Let’s cover the key ones in both categories, looking at their history, the types of projects they accredit, and what sets them apart.

International Carbon Offset Accreditation Schemes

1. UN Clean Development Mechanism (CDM)

The Clean Development Mechanism (CDM) was created under the Kyoto Protocol in 1997 and became operational in 2006. It was one of the first large-scale frameworks to allow developed countries to invest in emissions reduction projects in developing countries, earning them carbon credits known as Certified Emission Reductions (CERs).

Typical Project Types: CDM has accredited a wide range of projects, including:

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• Renewable energy projects (solar, wind, and hydropower)
• Methane capture and landfill gas recovery
• Industrial emission reduction projects

CDM credits were widely used in the early years of global carbon markets, but its significance has declined in recent years due to criticism over issues like additionality and the uneven distribution of projects, which often favored large-scale industrial ventures over local community-based initiatives.

2. Gold Standard

Launched in 2003 by the World Wildlife Fund (WWF) and other NGOs, the Gold Standard was designed to ensure that carbon offset projects deliver high environmental and social benefits. It arose in response to concerns that early carbon offset schemes, including CDM, did not fully address community impacts or sustainability.

Gold Standard projects are known for their focus on renewable energy, energy efficiency, and nature-based solutions, such as:

• Clean cookstove initiatives
• Community solar and wind projects
• Reforestation and forest conservation

Gold Standard-certified projects often contribute to the United Nations Sustainable Development Goals (SDGs) in addition to reducing carbon emissions. This makes it one of the most respected and comprehensive certification schemes in the carbon market.

3. Verra (VCS - Verified Carbon Standard)

Verra, originally known as the Verified Carbon Standard (VCS), was established in 2007. It is one of the largest voluntary carbon offset standards and accredits projects across the globe. However, Verra has recently faced scrutiny over concerns related to the effectiveness and integrity of some of its forest carbon projects.

Typical Project Types:

• REDD+ (Reducing Emissions from Deforestation and Forest Degradation) projects
• Renewable energy and energy efficiency projects
• Sustainable agricultural practices

Verra’s REDD+ projects are designed to incentivize forest conservation in developing countries by monetizing carbon sequestration from protecting forests. However, controversy has surrounded the program, particularly over claims that some REDD+ projects have overstated their emissions reductions, raising questions about the verification process.

4. REDD+ (Reducing Emissions from Deforestation and Forest Degradation)

REDD+ is a specific mechanism under the United Nations Framework Convention on Climate Change (UNFCCC) aimed at protecting forests in developing countries. It goes beyond carbon sequestration, emphasising the protection of biodiversity and the rights of indigenous communities.

Typical Project Types:

• Forest conservation and restoration
• Community-based forest management
• Agroforestry

REDD+ aims to reduce emissions from deforestation and forest degradation while promoting sustainable development. Many projects accredited under REDD+ also contribute to poverty alleviation and biodiversity protection, but challenges around measurement and verification remain.

UK-Based Carbon Offset Accreditation Schemes

1. Woodland Carbon Code (WCC)

The Woodland Carbon Code was introduced in 2011 by the UK government to provide a robust framework for woodland creation projects that sequester carbon. It ensures that UK-based tree planting initiatives deliver credible carbon offsets.

Typical Project Types:

• Woodland creation and afforestation
• Long-term forest management projects

The Woodland Carbon Code ensures that all accredited projects are independently verified and monitored, guaranteeing permanence, additionality, and reliable carbon sequestration. It plays a key role in the UK’s effort to increase forest cover as part of its net-zero goals.

2. Peatland Code

The Peatland Carbon Code was launched in 2015 to accredit projects focused on the restoration of the UK’s peatlands. Peatlands are significant carbon sinks, and their restoration prevents carbon emissions from degraded peatlands while promoting biodiversity and water quality.

Typical Project Types:

• Peatland restoration and rewetting
• Management of degraded peatland ecosystems

Peatlands store more carbon than all other UK vegetation types combined, making their preservation critical to the UK’s climate goals. Accredited projects under the Peatland Code must show measurable carbon savings and long-term ecological benefits.

3. UK Carbon Code of Conduct

The UK Carbon Code of Conduct is a newer initiative that provides guidelines for organisations involved in carbon sequestration and reduction projects within the UK. It sets out ethical standards and best practices to ensure transparency and integrity in the UK carbon market.

Typical Project Types:

• A broad range of UK-based nature-based solutions
• Community-based and industrial carbon reduction initiatives

While this code is still evolving, it is becoming increasingly important as the UK seeks to enhance domestic carbon reduction efforts, particularly through local nature-based solutions.

Summary

Carbon offsetting can be an effective tool in the fight against climate change, but only when done right. Accreditation schemes play a crucial role in ensuring that offset projects deliver real, measurable, and permanent emissions reductions. 

The international schemes, such as the CDM, Gold Standard, Verra, and REDD+, have set the groundwork for carbon markets by accrediting a wide range of projects across the globe. On the other hand, UK-based schemes like the Woodland Carbon Code and Peatland Code focus on local solutions, particularly in nature-based sequestration projects.

By supporting projects accredited by these schemes, individuals and organizations can be confident that their carbon offsets are making a tangible impact in the fight against climate change.