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About Rewind

Oxygen-Free Carbon Storage

Biomass and Sustainability

Safety and Environmental Integrity

Clarifying Misconceptions

About Rewind

Are Rewind credits certified?

Yes. We work with leading registries and carbon removal standards, such as Isometric, and have developed a full and comprehensive digital MRV (Monitoring, Reporting, and Verification) system.

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What does Rewind do?

Rewind delivers permanent, certified carbon removal by preserving plant biomass in anoxic (oxygen-free) environments (such as deep mines and marine basins) where carbon remains locked away for thousands of years.

How is this different from traditional carbon offsets?

Traditional offsets avoid increasing emissions instead of actually removing existing emissions from the atmosphere. Rewind removes CO₂ already in the atmosphere and stores it permanently. Our approach is scientifically validated, third-party certified, and ready to scale.

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Where are your projects located?

Rewind’s first commercial project, Project Ushba, is now operational in Georgia, where we store surplus plant residue in the sealed chambers of a deep underground mine. It follows pilot work in the Black Sea, one of the world’s largest natural anoxic basins, where we pioneered peer-reviewed research on marine biomass storage. But these locations are just the beginning. Rewind’s model is built to be replicated wherever biomass meets anoxic storage, making it designed to scale globally.

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What makes your solution permanent?

Biomass decomposes quickly in the presence of oxygen. But by placing it in oxygen-free environments, decomposition slows radically and carbon remains safely stored for more than a millennia, geologically locked in.

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Oxygen-Free (anoxic) Carbon Storage

How scalable is this approach?

Rewind’s model is designed to work wherever surplus biomass meets anoxic storage conditions. There are hundreds of thousands of unused mines around the world; vast sedimentary zones in oceans and estuaries, and marine basins like the Black Sea are capable of storing gigatons of CO₂.

By 2030, Rewind aims to remove one million tons of carbon annually through a growing network of deep mines, sediments, and marine basin carbon removal projects.

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Why are anoxic environments good for carbon storage?

No oxygen means limited decomposition and therefore no carbon released. These natural conditions preserve carbon securely and durably. Rewind applies this model to anywhere where oxygen isn’t present.

What are the different types of storage Rewind uses and how do they compare?

Rewind uses three core carbon storage approaches today, but our model is designed to scale far beyond this. What unites all our approaches is locking away carbon by injecting biomass into anoxic environments to prevent decomposition. These methods differ in setting, infrastructure, and stage of development, but share the same principle: long-term, nature-powered carbon preservation.

1. Deep Mine Storage (DMS)

Biomass is injected into deep, sealed chambers inside stable underground mines. anoxic conditions prevent decomposition, while stable geology ensures carbon will stay locked away for 10,000+ years.

Where: Project Ushba, Georgia, storing sawmill byproducts 1.3 km underground
Status: First certified credits expected in 2025; scaling to 100,000 tons annually by 2027
Advantages: Energy efficient, nature remediating, globally replicable, repurposes existing mine infrastructure

2. Marine Anoxic Carbon Storage (MACS)

In naturally anoxic marine basins, including the Black Sea, biomass can be stored without decomposing on the seafloor, just as nature has preserved organic matter such as shipwrecks for millennia.

Where: Black Sea
Status: Peer-reviewed research complete; certification in development with Puro and Isometric
Advantages: Gigaton-scale potential, proven environmental safety, minimal disturbance

3. Sediment Carbon Storage (SCS)

In this approach, biomass is injected beneath anoxic seabed sediments, often integrating with existing dredging operations. It’s ideal for localized carbon storage in permitted regions where dredged sediments are already present.

Where: 20-ton pilot completed in the Mediterranean
Status: Early-stage; scientific validation and certification underway
Advantages: Operates alongside existing marine activities, remediation of contaminated sites, adaptable, potentially lower-cost and locally deployable

By combining these three approaches, Rewind delivers a resilient carbon removal system— rooted in science and powered by nature—that works in tandem with Earth’s natural systems to deliver permanent as well as scalable impact.

What’s special about the Black Sea?

The Black Sea is one of the largest natural anoxic basins, a place where the deep waters contain no oxygen, which prevents decomposition and allows carbon to be safely preserved without emissions for thousands of years.

Every year, rivers flowing into the Black Sea deposit megatons of organic carbon, much of which settles onto the seabed and stays intact. This isn’t hypothetical: the Black Sea has naturally stored carbon, including at the sites of shipwrecks, for thousands of years.

It is ideal for Rewind’s model for several reasons:

Scale: Its deep anoxic layer holds enough volume to support gigaton-scale carbon removal
Stability: Its anoxic chemistry ensures long-term carbon preservation and environmental safety
Proximity: It sits at the heart of Europe’s agricultural belt, giving us ready access to large volumes of surplus sustainable biomass from surrounding countries

In short, the Black Sea is a naturally occurring, scientifically validated, and logistically viable carbon sink.

Is the Black Sea the only viable location?

No. The Rewind model works wherever surplus biomass and oxygen-free geology meet. This includes marine basins, deep mines, and sedimentary zones worldwide.

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Biomass and Sustainability

What is biomass?

Biomass refers to carbon-rich plant material, including sawdust and crop residue, which absorbs CO₂ as it grows. Without intervention, this biomass typically decomposes or is burned, releasing that carbon back into the air. Preserving biomass in anoxic storage stalls decomposition and therefore prevents CO₂ cycling back into the atmosphere.

What types of biomass do you use?

We use surplus, sustainably sourced surplus plant residue (byproducts from sawmills and agriculture) that would otherwise emit carbon through decomposition or burning.

All of it is non-edible, non-commercial, and not grown for Rewind. It’s already out there—we just make sure the carbon doesn’t return to the atmosphere.

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Is the biomass sustainably sourced?

Yes. All biomass is sourced from certified, responsible local suppliers. We follow strict sustainability criteria including not competing with food systems and using transparent supply chains with chain-of-custody tracking

We also audit and trace every batch through our MRV system, linking feedstocks to specific suppliers and final storage sites.

How much biomass is needed to remove 1 ton of CO2?

Approximately 1 ton of dry biomass holds 1 ton of CO₂. The exact ratio depends on the specific type of biomass and its moisture content. We test each batch for moisture and carbon density, and our MRV system adjusts removal values accordingly to ensure what we report is what we actually store.

Do emissions from transport cancel out the benefits?

Not at all. On the contrary, moving biomass takes far less energy than heating it. That’s why Rewind’s approach, which relies on transportation and natural storage conditions (not combustion or industrial processing), is one of the most energy-efficient carbon removal methods available. We also locate projects close to biomass sources to keep emissions even lower.

Safety and Environmental Integrity

Is this safe for the environment?

Yes. Our method is grounded in natural processes, our storage sites are geologically stable and oxygen-free, and we monitor processes rigorously. Projects are designed to protect—and restore—surrounding ecosystems.

What environmental benefits do Rewind projects offer?

Rewind restores. We repurpose unused infrastructure, reduce methane emissions and wildfire risks, support local habitats and rivers, and deliver measurable co-benefits for communities and ecosystems.

Is it still safe and effective at scale?

Yes. Our method is energy efficient and scalable through replication, not complexity. It’s designed for global deployment without compromising safety.

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Clarifying Misconceptions

Doesn’t carbon removal let polluters off the hook?

No. Carbon removal is essential alongside emission cuts. Even if emissions dropped today, legacy CO₂ must still be removed to meet global climate goals. Rewind addresses that critical gap.

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Isn’t planting trees simpler?

Trees help, but are fragile carbon sinks. They’re vulnerable to fire, disease, and climate shifts. Our solution offers durable, certified carbon removal that’s complementary to nature-based options like reforestation.

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How does preserving biomass remove carbon from the air?

Plants absorb CO₂ as they grow, storing it in their biomass. Without intervention, when the plant dies, that biomass decomposes, releasing the CO₂ back into the atmosphere. Rewind interrupts this process by preserving surplus biomass in oxygen-free environments where decomposition can’t occur, keeping carbon out of the air for thousands of years.

For example: In Georgia, we work with sawmills that produce tons of wood residue each year. Left alone, that material would decompose in open piles and emit CO₂. Instead, we store it securely underground, using natural geology to lock the carbon away.

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Is this just reducing emissions, or is it true removal?

This is true removal. Our process takes carbon dioxide that’s already in our atmosphere and stores it underground or underwater, permanently removing it from the carbon cycle.

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FAQ

About Rewind

Are Rewind credits certified?

What does Rewind do?

How is this different from traditional carbon offsets?

Where are your projects located?

What makes your solution permanent?

Oxygen-Free (anoxic) Carbon Storage

How scalable is this approach?

Why are anoxic environments good for carbon storage?

What are the different types of storage Rewind uses and how do they compare?

What’s special about the Black Sea?

Is the Black Sea the only viable location?

Biomass and Sustainability

What is biomass?

What types of biomass do you use?

Is the biomass sustainably sourced?

How much biomass is needed to remove 1 ton of CO2?

Do emissions from transport cancel out the benefits?

Safety and Environmental Integrity

Is this safe for the environment?

What environmental benefits do Rewind projects offer?

Is it still safe and effective at scale?

Clarifying Misconceptions

Doesn’t carbon removal let polluters off the hook?

Isn’t planting trees simpler?

How does preserving biomass remove carbon from the air?

Is this just reducing emissions, or is it true removal?

Read more on our blog.