# Our projects

## The Wren Classic Portfolio

### How we choose our projects

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Mangrove planter Mr. Win Maung (left), and youth ambassador Miss Earth Baitong Jareerat (right), inside their successfully restored mangroves.

## Wren members fund a variety of  _climate solutions_.

# 1. Engineered carbon dioxide removal

## These projects capture CO₂ and store it permanently, preventing release for centuries to millennia.

### Biochar carbon removal

## This project uses a process called pyrolysis to convert sawmill and forest residues into biochar, a carbon-rich charcoal. The biochar can then be applied to farmlands to improve soil health and crop output.

- Durable carbon storage  
- Utilizes organic waste  
- Enhances soil quality  
- Reduces pollution

[Learn more](https://www.wren.co/projects/biochar-carbon-removal)

### Enhanced rock weathering

## This project spreads crushed silicate rocks such as basalt on agricultural land, speeding up the Earth’s natural weathering cycle, and permanently removing carbon from the atmosphere.

- Scalable, peer-reviewed science  
- A permanent solution with natural co-benefits  
- High quality project data management

[Learn more](https://www.wren.co/projects/enhanced-mineral-weathering)

### Enhanced weathering on rice paddies

## This project permanently removes CO₂ from the atmosphere and supports smallholder farmers in India, Zambia, and Tanzania. By spreading abundant, locally-sourced crushed rock on rice paddies, the natural weathering process is accelerated to absorb CO₂.

- Uplifts smallholder farmers  
- Permanent carbon storage  
- Highly scalable  
- Optimal weathering locale

[Learn more](https://www.wren.co/projects/enhanced-weathering-on-rice-paddies)

### Underground biomass storage

## This project removes CO₂ from the atmosphere by taking residual or waste biomass leftover from timber and agricultural operations and producing carbon blocks that are stored safely underground.

- Repurposes organic waste  
- Permanent carbon removal  
- Creates green jobs  
- Highly scalable

[Learn more](https://www.wren.co/projects/underground-biomass-storage)

# 2. Policy

## These projects work to advance and implement climate-positive laws and regulations.

### Carbon Gap

## This project advances policies that maximize Europe’s contribution to the rapid and responsible global scale-up of carbon dioxide removal (CDR) needed for effective climate change mitigation.

- Advances carbon removal policy  
- Scales durable CDR  
- Sets quality principles for CDR  
- Provides research for policymakers

[Learn more](https://www.wren.co/projects/carbon-gap)

### Carbon Removal Alliance

## This project advances policies that support a diverse set of permanent, high-quality carbon removal technologies.

- Advances carbon removal policy  
- Provides context for lawmakers  
- Accelerates climate innovation  
- Creates community benefits

[Learn more](https://www.wren.co/projects/carbon-removal-alliance)

# 3. Nature-based solutions

## These projects protect, restore, or sustainably manage ecosystems to address climate change while supporting biodiversity and human well-being.

### Forest resilience against wildfires

## This project restores and protects forests, watersheds, ecosystems, and communities in the Western United States by catalyzing funds and gathering partners needed to accelerate ecological restoration projects.

- Prevents wildfires  
- Unlocks conservation finance  
- Forms community partnerships  
- Utilizes scientific insights

[Learn more](https://www.wren.co/projects/forest-resilience-against-wildfires)

### Improved forest management in Maine

## This project helps small landowners in Maine shift from short-rotation harvest cycles to longer-term forest management that stores and sequesters more carbon.

- Builds biodiversity  
- Supports family forest owners  
- Preserves native ecosystems  
- Removes carbon dioxide

[Learn more](https://www.wren.co/projects/improved-forest-management-in-maine)

### Mangrove planting in Myanmar

## This project reforests degraded mangrove ecosystems in Myanmar’s Ayeyarwady Division.

- Promotes biodiversity  
- Improves climate resiliency  
- Sequesters carbon in soil

[Learn more](https://www.wren.co/projects/mangrove-planting-in-myanmar)

### Tech-enabled rainforest protection

## This project works with Indigenous Amazonians to protect their rainforest home. Using satellite monitoring and drones, Indigenous monitors detect deforestation early. This allows communities to prevent deforestation before it reaches a large scale.

- Promotes Indigenous land rights  
- Protects biodiversity  
- Prevents deforestation

[Learn more](https://www.wren.co/projects/tech-enabled-rainforest-protection)

# 4. Super pollutant mitigation

## These projects prevent the emissions of powerful, short-lived greenhouse gases like methane and HFCs, which trap far more heat than CO₂ but remain in the atmosphere for a shorter time.

### Adipic acid nitrous oxide abatement

## This project reduces nitrous oxide (N₂O) emissions from a chemical plant in Florida. N₂O is 273× more harmful than CO₂ and in 2022, it was responsible for 6% of human-generated greenhouse gas emissions in the United States.

- Captures nitrous oxide emissions  
- Highly measurable  
- Low cost  
- Readily deployable technology

[Learn more](https://www.wren.co/projects/adipic-acid)

### Landfill methane abatement

## This project captures methane (CH₄) from a landfill and prevents its release into the atmosphere by converting it into energy or less harmful gases using electricity generators and high-temperature enclosed flares.

- Displaces fossil fuel energy  
- Prevents methane emissions  
- Saves lives by reducing air pollution  
- Low cost

[Learn more](https://www.wren.co/projects/landfill-methane-abatement)

### Refrigerant destruction

## This project permanently destroys harmful refrigerants that would otherwise be released into the atmosphere—thereby fighting global warming, and helping to restore the planet's ozone layer.

- Prevents ozone depletion  
- Highly measurable  
- Low cost  
- Creates green jobs

[Learn more](https://www.wren.co/projects/refrigerant-destruction)

# 5. Other

## Some projects don’t fit neatly into one of our main categories, but they still make a meaningful impact in the fight against climate change.

### Clean cookstoves in East Africa

## This project reduces greenhouse gas emissions by transitioning households and businesses in East Africa from charcoal to clean alternatives, decreasing the reliance on non-renewable fuels.

- Saves lives by reducing air pollution  
- Promotes gender equality  
- Creates sustainable jobs  
- Builds clean cooking infrastructure

[Learn more](https://www.wren.co/projects/clean-cookstoves-in-east-africa)

### Members fund a mix of climate solutions via _The Wren Classic Portfolio_

- Managed automatically  
- Diversified projects  
- Optimized for impact  
- Affordable price

## About

The Wren Classic Portfolio offsets carbon through a curated selection of effective climate projects. Allocations are periodically updated to maximize impact.  
We look for projects with proven results, lasting impact, and strong support for systems change. These projects wouldn’t happen without your funding.

## Portfolio updates

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June 17, 2026\  
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How wood residues create clean energy, biochar, and jobs](https://www.wren.co/blog/how-wood-residues-create-clean-energy-biochar-and-jobs)

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May 28, 2026\  
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Advancing carbon removal from policy protection to deployment](https://www.wren.co/blog/advancing-carbon-removal-from-policy-protection-to-deployment)

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April 16, 2026\  
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5 million more tonnes of CO₂e avoided and counting](https://www.wren.co/blog/5-million-more-tonnes-of-co-e-avoided-and-counting)

[See all updates](https://www.wren.co/blog)

## How is the money spent?

### Category
Portfolio allocation

- [Engineered carbon dioxide removal](https://www.wren.co/projects#engineered-carbon-dioxide-removal)  
  26.5%  
- Biochar carbon removal (Investment)  
  19.9%  
- Enhanced rock weathering  
  2.3%  
- Underground biomass storage  
  2%  
- Enhanced weathering on rice paddies  
  1.3%  
- Biochar carbon removal (Certified offset)  
  1%

- [Policy](https://www.wren.co/projects#policy)  
  4.9%  
- Carbon Gap  
  3%  
- Carbon Removal Alliance  
  1.9%

- [Nature-based solutions](https://www.wren.co/projects#nature-based-solutions)  
  25%  
- Improved forest management in Maine  
  13%  
- Tech-enabled rainforest protection  
  5%  
- Mangrove planting in Myanmar  
  5%  
- Forest resilience against wildfires  
  2%

- [Super pollutant mitigation](https://www.wren.co/projects#super-pollutant-mitigation)  
  30.6%  
- Adipic acid nitrous oxide abatement  
  14.9%  
- Landfill methane abatement  
  12.6%  
- Refrigerant destruction  
  3.1%

- [Other](https://www.wren.co/projects#other)  
  13%  
- Clean cookstoves in East Africa  
  13%

### Contributions by month

2019  2020  2021  2022  2023  2024  2025  2026  $100K  $200K  $300K  $400K

### How we choose our projects

## We choose projects that maximize climate impact per dollar and contribute to sustainable and equitable systems change.

↑  
For example, lidar scans are used to assess forest health and carbon storage potential.

# 1. Proven results

We evaluate projects against 250+ indicators to ensure projects meet our standards for climate impact and systems change. We go through hundreds of pages of project documents and dig deep into measurements and methods to ensure the use of best-in-class carbon accounting techniques.

We cross-check our findings with peer-reviewed research and spend hours talking with industry experts to surface any unseen risks. Typically, this process takes a month or more and as a result, less than 5% of projects that come our way make it onto our platform.

**How we choose projects**  
1. Proven results  
2. Lasting impact  
3. Wouldn’t happen without your funding  
4. Support for systems change

↑  
Wren members fund the permanent destruction of potent greenhouse gas emissions from refrigerants.

# 2. Lasting impact

We choose climate projects that are able to remove or keep carbon out of the atmosphere. For nature-based projects, like tree planting, we make sure there is a “buffer” built into the project design to account for risks like wildfire or logging. For projects like enhanced mineral weathering, we make sure the proper measurements are used so we know when the carbon is removed and for how long it will stay out of the atmosphere (this can be up to thousands of years!).

**How we choose projects**  
1. Proven results  
2. Lasting impact  
3. Wouldn’t happen without your funding  
4. Support for systems change

↑  
For most projects, Wren is one of the sole purchasers of carbon credits, limiting the risk of double counted credits.

# 3. Wouldn’t happen without your funding

Every project on Wren needs funding in order to succeed. That funding goes towards purchasing the supplies and paying for the team members necessary to make those projects happen. If a project would be profitable on its own without us, it isn't eligible for Wren.

For instance, if a landowner has protected their forest for hundreds of years and there’s no reason they’d start logging now, we won’t fund them. Their forest will likely stay standing even without money from carbon offsets.

Similarly, in most countries today renewable energy projects can be highly profitable. We wouldn’t fund a renewable energy project unless we could be certain it needs our funding.

**How we choose projects**  
1. Proven results  
2. Lasting impact  
3. Wouldn’t happen without your funding  
4. Support for systems change

↑  
Drone footage provides early warning of deforestation, helping communities and authorities in the Amazon protect their forests.

# 4. Support for systems change

Wren’s goal is to support the systems change needed to build a sustainable and equitable future in which human and planetary health is secure. To support this, we choose projects that contribute to social, cultural, political, and economic change. For example, we fund policy advocacy because we know we need governments to step up and regulate corporations.

We also support innovative carbon removal technologies because we know our funding can help these companies scale. We also think deeply about how a project advances the United Nations Sustainable Development Goals and prioritize projects that center the voices of those on the frontline of the climate crisis – such as Indigenous Peoples and Local Communities.

**How we choose projects**  
1. Proven results  
2. Lasting impact  
3. Wouldn’t happen without your funding  
4. Support for systems change

# Archived projects

## When projects are archived on Wren, they will appear here along with a reason for archival.

- Mangrove conservation in Mexico  
  Archived: May 2026  
  Archived due to shifting their on-the-ground priorities away from developing a carbon project and more toward community-driven educational efforts.  
  [More](https://www.wren.co/projects/mangrove-conservation-in-mexico)

- Carbon180  
  Archived: Dec 2025  
  We’re shifting our policy funding to Europe, where CDR legislation is progressing and funding gaps persist, while Carbon180 remains well-funded without additional support from Wren.  
  [More](https://www.wren.co/projects/carbon180)

- Clean Air Task Force  
  Archived: Dec 2025  
  We’re shifting our policy funding to Europe, where CDR legislation is progressing and funding gaps persist, while CATFUS remains well-funded without additional support from Wren.  
  [More](https://www.wren.co/projects/clean-air-task-force)

- Refrigerant destruction (Recoolit)  
  Archived: Dec 2025  
  We sold out of Recoolit credits! We are happy to see they signed an agreement with Google and Terraset and look forward to seeing them continue to grow.  
  [More](https://www.wren.co/projects/recoolit)

- Bio-oil carbon removal  
  Archived: Aug 2025  
  Archived in the Wren Classic Portfolio for strong traction with major carbon credit buyers and high cost, and in the Wren Trailblazer Portfolio to prioritize super-pollutant avoidance.  
  [More](https://www.wren.co/projects/bio-oil-carbon-removal)

- Mangrove planting in Pakistan  
  Archived: Jun 2025  
  Archived to align our evolving portfolio standards with recent independent assessments.  
  [More](https://www.wren.co/projects/mangrove-planting-in-pakistan)

- Community agroforestry in Timor-Leste  
  Archived: Jun 2025  
  Archived due to lack of available credits for purchase. The door is open for this project to re-enter the portfolio in the future when there is sufficient supply to match Wren's demand.  
  [More](https://www.wren.co/projects/community-agroforestry)

- Community tree planting  
  Archived: Dec 2022  
  Archived due to lack of available credits for purchase. The door is open for this project to re-enter the portfolio in the future when there is sufficient supply to match Wren's demand.  
  [More](https://www.wren.co/projects/community-tree-planting)

- Clean cooking fuel for refugees  
  Archived: Dec 2022  
  Archived after undershooting production volume estimates. In addition, the project did not meet new verification standard required by Wren in 2023.  
  [More](https://www.wren.co/projects/clean-cooking-fuel)

# The climate crisis requires massive action, and you can start today.

## Carbon offsets alone won't end the climate crisis, but calculating and offsetting your carbon footprint is a great way you can make a difference.

[Get started](https://www.wren.co/continue)

#### Wren Climate, PBC

Take real, effective climate action with Wren’s all-in-one climate platform.

#### How we choose our projects
1. Proven results
2. Lasting impact
3. Wouldn’t happen without your funding
4. Support for systems change