Credit categories

Based on Oxford’s Principles, our portfolio is distributed across five categories ranging from emissions reductions to conservation and long-lived removal.

Science-based credits

Oxford's Principles for Carbon Offsetting provides a robust framework across multiple categories. The portfolio is diversified across category, technology, and geography to mitigate risk while maximizing impact.
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Oxford Type I

Emission reductions

This category covers a wide range of projects that aim to reduce and avoid emissions versus business as usual. Examples include: renewable energy, destruction of refrigerants that would otherwise be vented to the atmosphere, and capture of methane emitted from landfills.
Example projects

Tradewater Honduras 1.0 Project


Clinton Landfill Gas Project

United States of America


Actively curbing potent greenhouse gas emissions where they otherwise would occur is one of the most effective actions we can take today. Avoided emissions from this category are typically irreversible, and it’s often straightforward to quantify the exact amount of CO2 emissions avoided through project activity.


Additionality: Carbon credits count as additional only when funded by the credit itself. If a project is already profitable without this financing, or mandated by law, it's not additional. We are invariably cautious of projects, especially many renewable ones, that don't meet this criterion.

Potential overestimation: Some projects, such as distributing cleaner cookstoves in rural areas, might exaggerate their emission reductions by assuming too much stove usage or by overestimating biomass that would have emitted without the program. We focus on choosing projects that have clear & transparent metrics.
Oxford Type II


This category typically consists of nature-based projects that help retain an existing source of natural carbon storage that would otherwise be at risk – for example, rainforests that would be cut down for development or peat bogs that might be drained for agriculture.
Example projects

Manoa Avoided Deforestation


Katingan Mentaya Peatland Preservation



To mitigate the worst impacts of climate change, we must preserve natural carbon reserves and prevent their release into the atmosphere. These projects are already available at scale and can drive impact now.


Overestimation of Impact: Reduction projects can overestimate how much carbon would have been emitted if the project did not exist and  therefore overestimate the impact of the project.

Durability: Nature-based projects are susceptible to risks like fire and infestations. They also run the risk of having their benefit reversed after the project ends.
Oxford Type III

Capture and storage

This category typically consists of industrial, point source carbon capture (e.g., at a smokestack or an oil well), with the carbon then stored for the long-term, for instance in underground caves or wells.
Example projects

Enchant Energy: Coal Carbon Capture and Sequestration

United States

Project Interseqt: Carbon Capture & Storage from Ethanol

United States


Capturing and sequestering CO2 at major point sources of emissions is an efficient way to remove meaningful amounts of carbon from the atmosphere and thereby drive meaningful impact.


Additionality: Because many of these projects, at least in the United States, also benefit from tax credits, carbon credits may not be additional because the credits themselves are not a but-for cause of the project.

Limited availability: For similar reasons, credits in this category are uncommon because projects in this category often do not generate them.
Oxford Type IV

Short-lived removal

This category typically consists of nature-based projects that remove existing carbon and store it in new plants, trees, or soil–for example, planting trees in an area that has previously been clear cut or restoring plant life to tidal wetlands.
Example projects

Yarra Yarra Biodiversity Project


Kootznoowoo Native Community Forestry Project

United States


Ecosystems, especially plants, are our best tools for atmospheric carbon removal. By investing in restoring degraded ecosystems around the world, we can harness nature's power to eliminate millions of tons of carbon.


Difficulty of Implementation: Put simply, implementing an effective restoration or afforestation project is hard. Projects can face setbacks if new trees don’t survive and need to be replanted. What’s more, new plantings can take years to start removing carbon at scale.

Durability: Nature-based projects are susceptible to risks like fire and infestations. They also run the risk of having their benefit reversed after the project ends.
Oxford Type V

Long-lived removal

This category encompasses a broad range of cutting-edge engineered solutions. While they hold immense potential, many, like direct air capture technology and carbon storage through enhanced rock weathering, are still not available at scale.
Example projects

Arca: Ultramafic Rock Mineralization


Charm Industrial Bio-oil Sequestration

United States


The best science suggests that any pathway to avoiding the worst effects of climate change will require between 100 and 1,000 gigatons of carbon removal over the course of the 21st century. This category represents the best opportunity to deliver on that gigaton scale permanent removal by leveraging new technology.


Limited Supply: These technologies have not reached operational scale, meaning that they are limited in availability and immediate impact.

Technology risk: Technologies in this category are largely experimental, so there are not yet fully-developed certifications and processes to measure and verify the amount of carbon removed.

Price: Because the technologies are subscale and experimental, tons of CO2e from this category can cost hundreds or even thousands of dollars.

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