How do I check a carbon credit is real?

Ask for the serial numbers and look them up in the Verra Registry or the Gold Standard Impact Registry. A genuine retirement is public, names your organisation and cannot be resold.

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Carbon Credits vs Carbon Offsets: What's the Difference?

Q: Is a carbon credit the same as a carbon offset?

Almost: the credit is the certified unit of one tonne of CO2e; the offset is the result of retiring it against your emissions. Every offset starts as a credit, but an unretired credit is not an offset.

Q: Can offsets replace cutting emissions?

No. They complement reductions and cover residual emissions you cannot yet eliminate. Under the SBTi corporate net-zero standard they cannot count towards emission-reduction targets.

Q: What is the difference between a carbon credit and an EU ETS allowance?

An allowance is a government-issued permission to emit one tonne within a regulated cap. A voluntary carbon credit is issued to a project for a verified tonne reduced or removed. They belong to different systems and are generally not interchangeable.

25 Jun 2026 in Scientific articles · Updated 8 Oct 2026

Carbon Credits vs Carbon Offsets: What's the Difference?

A carbon credit is the tradable instrument — one tonne of CO₂ reduced or removed, certified by a standard like Verra or Gold Standard — while a carbon offset is what happens when you retire that credit to compensate your own emissions. In everyday use the terms overlap: you buy credits, and retiring them “offsets” your footprint. The distinction only starts to matter when someone asks you to prove the claim.

The difference in 30 seconds

Carbon credit = the unit. 1 credit = 1 tonne of CO₂e avoided or removed, issued to a verified project.
Carbon offset = the act. You retire a credit so that tonne counts against your emissions, once, for you.
Retirement matters. A credit only becomes an offset when it is permanently retired in a registry — otherwise it can be resold to someone else.
Quality matters. Certification is what separates credible credits from unverifiable claims.
Neither is a reduction. Buying a tonne is not the same as not emitting a tonne, and no serious framework treats them as interchangeable.

Where the confusion actually comes from

“Carbon credit” is used for two different things, and mixing them up is the source of most of the muddle:

Compliance allowances. In regulated systems such as the EU Emissions Trading System, an allowance is a government-issued permission to emit one tonne. Covered installations must surrender one for every tonne they emit. These are not project credits, and companies outside the scheme generally cannot use them.
Voluntary carbon credits. Issued to a specific project that reduced or removed a tonne relative to a baseline, verified by an independent auditor and serialised in a public registry. This is what almost every corporate buyer means by “offsetting”.

The words are the same; the instruments are not. When a supplier is vague about which one they are selling, that is itself information.

How a credit is actually created

Methodology. The project follows an approved methodology that defines the baseline — what would have happened anyway.
Validation. An accredited independent auditor checks the project design against that methodology before it starts issuing.
Monitoring. The project measures what actually happened over a defined period.
Verification. A second independent check confirms the monitored results.
Issuance. The registry issues serialised credits — each one traceable to a project, a vintage year and a methodology.
Retirement. The buyer's credits are permanently cancelled in the registry, in the buyer's name. That public record is the offset.

Every step in that chain is checkable. If your supplier cannot walk you through it for the specific tonnes you bought, you do not have a claim you can defend.

Avoidance vs removal — the distinction that matters most

Two credits can both say “one tonne” and mean very different things:

Avoidance / reduction credits fund emissions that supposedly will not now happen — protecting a forest from clearance, replacing a polluting cookstove, building renewable capacity. The tonne is counterfactual, so the credibility rests entirely on the baseline.
Removal credits take CO₂ physically out of the atmosphere and store it — reforestation, restoration, engineered removals. The tonne is observable, but permanence has to be managed.

Both have a legitimate role. But under most net-zero frameworks only removals can neutralise your residual emissions at the end state, which is why the mix you buy should be a deliberate decision rather than whatever was cheapest.

How businesses use them in practice

The credible sequence is always the same: measure, reduce, then compensate the remainder. Companies calculate their footprint, cut the emissions they can, buy certified credits matching the residual tonnes, retire them, and file the retirement documentation with their ESG reporting.

What has changed is the framing. Under the Science Based Targets initiative's corporate net-zero standard, purchased credits do not count towards emission-reduction targets. They sit outside the target as beyond-value-chain mitigation, with permanent removals reserved for neutralising residual emissions at net zero. In other words: offsetting is something you do in addition to your targets, not instead of them. Most of the hard work is in the value chain — see Scope 3 emissions and carbon offsets.

What you can and cannot claim

Claim language is tightening, and this is where a lot of companies are exposed:

Product-level neutrality claims. From 27 September 2026, the EU's Empowering Consumers Directive bans marketing a product to consumers as carbon neutral, climate neutral or net zero on the basis of offsetting. Company-level reporting is not affected, but consumer-facing product claims need to change.
Contribution claims work. “We cut our emissions by X% and funded the removal of Y tonnes through [named project, registry, serial numbers]” is accurate, defensible and still compelling.
Keep the evidence. Project name, standard, vintage, serial numbers, retirement date, beneficiary. If you cannot produce it on request, do not make the claim.

For where the line sits between honest compensation and greenwashing, see are carbon offsets greenwashing?

Where Evertreen fits

Evertreen provides Verra- and Gold Standard-certified credits, retired on your behalf with the documentation your reporting needs — and pairs them with traceable tree planting from £1.5 per tree, documented through project updates and filmed by the planting teams. Certified tonnes for the claim; visible trees for the people you are trying to convince.

Start by sizing your footprint with the CO₂ calculator, then decide the split. If you are comparing standards, read Verra vs Gold Standard; if you are comparing suppliers, read how to choose a carbon offset provider.

Frequently asked questions

Is a carbon credit the same as a carbon offset? Almost: the credit is the certified unit (1 tonne CO₂e); the offset is the result of retiring it against your emissions. Every offset starts as a credit, but a credit sitting unretired in an account is not an offset.

What makes a credit credible? An approved methodology, independent validation and verification, a serialised registry entry, and permanent retirement in a public registry under your name.

Can offsets replace cutting emissions? No. They complement reductions, covering residual emissions you cannot yet eliminate. Under the SBTi net-zero standard they cannot count towards reduction targets at all.

What is the difference between a carbon credit and an EU ETS allowance? An allowance is a government-issued permission to emit within a regulated cap. A voluntary carbon credit is issued to a project for a verified tonne reduced or removed. Different systems, different rules, generally not interchangeable.

Can a carbon credit be used twice? Not if the registry works as intended. Retirement permanently cancels the serial number and records the beneficiary, which is precisely what prevents double counting — and why proof of retirement is non-negotiable.

Do I need removal credits or avoidance credits? Both have a role, but only removals neutralise residual emissions under most net-zero frameworks. Decide the mix deliberately and record why.

How do I check a credit is real? Ask for the serial numbers and look them up in the Verra Registry or Gold Standard Impact Registry. A genuine retirement is public, names your organisation and cannot be resold.

26 Sep 2026

Reforestation vs Afforestation: What's the Difference?

Reforestation replants trees where a forest recently stood but was lost to logging, fire or clearing, whereas afforestation establishes forest on land that has had no forest in recent history. Both raise tree cover, yet they carry very different ecological stakes, and the right approach depends on what the land was before a single seedling goes in the ground. What each term actually means Reforestation. Re-establishing forest on land that carried forest until recently — restoring a degraded, burned or cleared site back towards the ecosystem it just lost. The reference point is known and recent. Afforestation. Planting forest on ground that has not been woodland in recent history, such as former pasture, open grassland, moorland or scrub. Here a new ecosystem is created, not restored. The timescale test. The practical line is whether forest existed on that spot within living memory; if it did, replanting is reforestation, if it did not, it is afforestation. Not just "greening". Both aim at functioning forest, not rows of a single fast-growing species — structure and native diversity matter more than raw tree count. Why the label matters. It signals ecological risk, not only method: more trees is not automatically more nature, and the wrong trees in the wrong place can set an ecosystem back. Where each one belongs The useful question is not which word is better but which land you are standing on: Reforestation fits recently logged or burned forest, cleared agricultural land that was forest a generation ago, degraded slopes losing soil, and fragmented woodland where new planting can reconnect existing patches. Afforestation fits genuinely degraded, non-natural land that will not recover unaided — abandoned industrial ground, severely eroded slopes, exhausted farmland with no seed source nearby. Neither fits intact natural grassland, savanna, peatland, wetland or heath. These are not "empty land waiting for trees"; they are functioning ecosystems with their own specialist species and, often, enormous soil carbon stores. The benefits — and the real risks Reforestation is usually the safer bet. It restores a habitat that local wildlife already depends on, rebuilds soil structure and water cycles, and reconnects fragmented patches of existing forest, so the ecological payoff is relatively predictable. Afforestation can add real value on genuinely degraded land that will not recover on its own — but planted in the wrong place it does harm. Dense tree cover on ancient grasslands, peatlands or wetlands can crowd out specialist plants and animals that need open habitat, and can even release carbon those soils had stored for centuries. You can see how we screen and document each site on our planting projects page, where location and land history feed into the decision. Which stores carbon more reliably? Context decides, but reforestation of a recently lost forest tends to lock away carbon more dependably. The climate, soils and native species are already suited to woodland, so the trees are likelier to survive to maturity and the existing soil carbon stays undisturbed. Afforestation can sequester carbon as well, yet only when the planting does not damage carbon-rich ground beneath it — peatland drained and ploughed for trees can emit far more CO₂ than the young forest will ever capture, turning a climate project into a net loss for years. Because these numbers hinge on assumptions, we publish ours openly; you can read exactly how we estimate tree CO₂ rather than trusting a single headline figure. The underlying biology is in how do trees absorb CO₂. The terms you will also meet Natural regeneration. Letting a site recover on its own by removing the pressure — grazing, fire, clearing — rather than planting. Often cheaper, often more biodiverse, and frequently the correct answer where a seed source survives nearby. Assisted natural regeneration. A middle path: protect the site, control invasives, and fill gaps with planting only where recovery stalls. Restoration. The broader goal that includes all of the above — returning ecological function, not simply raising a tree count. A serious project will tell you which of these it is doing and why. "We planted a million trees" answers none of those questions, which is precisely why the number gets quoted so often. How Evertreen chooses and tracks planting We focus on native-species, community-based planting on sites where trees genuinely belong, then show every project's location so you can follow it with field photos and updates instead of a vague promise that something, somewhere, was planted. Each of the trees you fund from £1.5 is tied to a real project in a known location and, wherever possible, to the restoration of a forest that was recently lost — keeping the emphasis on the right species in the right place, which is the single factor that most decides whether planting helps or harms. Frequently asked questions Is reforestation always better than afforestation? Not always, but it is usually the lower-risk option because it restores an ecosystem that recently existed. Afforestation is beneficial on genuinely degraded, non-natural land and harmful on intact grasslands, moorland or peat. Can afforestation damage the environment? Yes. Planting trees on natural grasslands, peatlands or wetlands can reduce biodiversity and release long-stored soil carbon, sometimes outweighing the carbon the new trees absorb over decades. Which removes more CO2 from the atmosphere? It depends on the site. Reforestation of recently lost forest is generally more reliable, while afforestation only delivers a net gain when it avoids disturbing carbon-rich soils. What is the difference between reforestation and natural regeneration? Reforestation actively plants trees; natural regeneration removes the pressure and lets the forest return by itself. Where a seed source survives, regeneration is often cheaper and more biodiverse. Does planting native species matter? Considerably. Native species support the local food web, cope with local conditions and are far likelier to survive, which is what turns a planting number into an actual forest. Is a plantation the same as a forest? No. A single-species plantation can store carbon but supports a fraction of the biodiversity, and it is usually managed for harvest rather than permanence. How can I tell whether a project is doing this properly? Ask what the land was before, which species are planted, who maintains the site and how survival is monitored. Projects that can answer all four are the ones worth funding. { "@context": "https://schema.org", "@type": "FAQPage", "mainEntity": [ {"@type": "Question", "name": "Is reforestation always better than afforestation?", "acceptedAnswer": {"@type": "Answer", "text": "Not always, but it is usually lower risk because it restores an ecosystem that recently existed. Afforestation helps on genuinely degraded non-natural land and harms intact grasslands, moorland or peat."}}, {"@type": "Question", "name": "Can afforestation damage the environment?", "acceptedAnswer": {"@type": "Answer", "text": "Yes. Planting trees on natural grasslands, peatlands or wetlands can reduce biodiversity and release long-stored soil carbon, sometimes outweighing the carbon the new trees absorb."}}, {"@type": "Question", "name": "Which removes more CO2, reforestation or afforestation?", "acceptedAnswer": {"@type": "Answer", "text": "It depends on the site. Reforestation of recently lost forest is generally more reliable, while afforestation delivers a net gain only when it avoids disturbing carbon-rich soils."}}, {"@type": "Question", "name": "What is the difference between reforestation and natural regeneration?", "acceptedAnswer": {"@type": "Answer", "text": "Reforestation actively plants trees, while natural regeneration removes the pressure and lets forest return by itself. Where a seed source survives, regeneration is often cheaper and more biodiverse."}}, {"@type": "Question", "name": "Does planting native species matter?", "acceptedAnswer": {"@type": "Answer", "text": "Considerably. Native species support the local food web, cope with local conditions and are far likelier to survive, which is what turns a planting number into an actual forest."}}, {"@type": "Question", "name": "Is a plantation the same as a forest?", "acceptedAnswer": {"@type": "Answer", "text": "No. A single-species plantation can store carbon but supports a fraction of the biodiversity and is usually managed for harvest rather than permanence."}}, {"@type": "Question", "name": "How can I tell whether a planting project is done properly?", "acceptedAnswer": {"@type": "Answer", "text": "Ask what the land was before, which species are planted, who maintains the site and how survival is monitored. Projects that can answer all four are the ones worth funding."}} ] }

23 Sep 2026

What Is a Carbon Credit? A Plain-English Guide

A carbon credit is a tradable certificate that represents one tonne of carbon dioxide equivalent (CO₂e) either avoided or removed from the atmosphere. In practice a credit lets a buyer take responsibility for emissions they cannot yet eliminate by funding a verified climate benefit somewhere else. The unit is deliberately simple — one credit, one tonne — but the quality behind that tonne is not. What gives a credit real value is how it was measured, whether an independent standard verified it, and whether it was permanently retired so the same tonne can never be sold or claimed twice. How a carbon credit is created and verified A project acts. A developer runs an activity that either prevents emissions, such as protecting a standing forest, or pulls carbon out of the air, such as growing new trees. The impact is measured. The tonnes of CO₂e are quantified against a baseline — what would realistically have happened without the project. An independent standard verifies it. Bodies such as Verra and Gold Standard audit the methodology and evidence before any credits are issued. Credits are issued, then retired. Each verified tonne gets a serial number on a public registry and becomes a real claim only once it is retired against a single buyer. The claim stays traceable. Anyone can look up the retired serial number, which is what stops one tonne being counted by several parties. Two systems, one confusing word "Carbon credit" describes two different instruments, and conflating them causes most of the confusion in the market: Compliance allowances exist inside regulated schemes such as the EU Emissions Trading System. A government issues a fixed number of permits to emit, and covered installations must surrender one per tonne emitted. The cap is the policy; the price is the consequence. Voluntary carbon credits are issued to specific projects for tonnes reduced or removed against a baseline, verified independently, and bought by organisations under no legal obligation to do so. Almost everything a company buys to "offset" is the second kind. If a supplier is vague about which they are selling, that is itself a useful signal. The distinction is unpacked further in carbon credits vs carbon offsets. Avoidance credits versus removal credits This is the distinction that matters most, and the one most often blurred. An avoidance (or reduction) credit stops a tonne from being emitted — it slows the problem but adds nothing back to the ledger. A removal credit physically takes a tonne of carbon out of the atmosphere and stores it in trees, soil, or rock. Both can be legitimate, but they are not interchangeable, and in a footprint report, mixing the two can make progress look larger than it really is. If you want to see what sits behind each type, our explainer on verified carbon credits sets out exactly what "verified" should guarantee. What decides a credit's price There is no single price of carbon, because a credit is a claim on a specific project rather than a commodity: Project type — removals cost more than avoidance; engineered removals cost far more than nature-based ones. Vintage — the year the tonne was verified. Recent vintages generally command more, since buyers discount credits issued under superseded methodologies. Co-benefits — verified community and biodiversity outcomes add a premium. Geography and volume — some regions are in higher demand, and larger purchases price better. Ranges and what they buy are set out in how much carbon offsets cost. How to check a credit is what it claims Ask for the serial numbers and look them up in the public registry. A genuine retirement names the beneficiary and cannot be reversed. Ask which methodology and version the project used, not just which registry certified it — quality now varies far more between methodologies than between standards. Check the vintage and ask why, if it is old. For forestry, ask about the buffer pool and the monitoring plan that covers fire, disease and reversal. Confirm the retirement timeline in writing before you pay. The failure mode to avoid is buying a credit nobody can look up. If it cannot be verified by a third party, it cannot safely go in your report. How businesses buy, retire, and use credits Most companies begin by measuring, because you cannot credibly offset what you have not counted. A free tool such as the Evertreen CO₂ calculator turns activity data into an estimated footprint, and the business then buys credits equal to the tonnes it wants to cover. Crucially, the purchase becomes a genuine claim only when the credit is retired in your name on the registry — buying without retiring leaves the tonne available for someone else to count. Retirement is the step that turns a receipt into an accountable outcome, and credible buyers cut their own emissions first, using quality credits for the remainder rather than as a licence to keep polluting. One accounting note worth stating plainly: under the SBTi corporate net-zero standard, credits do not count towards emission-reduction targets. They sit outside the target, with removals neutralising residual emissions at net zero. Buying credits versus planting trees directly An audited credit gives you a documented tonne today; planting gives you a visible, growing removal you can follow for years. With Evertreen you can combine both: certified Verra and Gold Standard credits are available on request when you need registry-grade tonnes, while trees in named, located projects from £1.5 per tree act as a complementary, long-term removal you can follow through each project's location, photos and updates. The goal is not to crown one label the winner but to match the tool to the claim — audited tonnes now, or a real tree putting down roots and adding removal over time. Frequently asked questions Does one carbon credit always equal one tonne of CO2? Yes. By definition one credit equals one tonne of CO2 equivalent. What varies is quality: how the tonne was measured, whether an independent standard verified it, and whether it was retired. What does retiring a carbon credit mean? Retiring permanently cancels the credit on its registry and assigns the tonne to a single buyer, so it cannot be resold or double-counted. Until a credit is retired, the climate claim is not complete. What is the difference between avoidance and removal credits? Avoidance credits prevent emissions that would otherwise happen, while removal credits take carbon dioxide out of the atmosphere and store it. Both can be useful, but they should be reported separately rather than treated as equal. Who issues carbon credits? Independent standards such as Verra and Gold Standard issue credits to projects after third-party auditors validate the design and verify the results. Can individuals buy carbon credits? Yes, usually through a provider that aggregates and retires on their behalf, since registries are set up for institutional accounts. Are carbon credits the same as an EU ETS allowance? No. An allowance is a government-issued permission to emit within a regulated cap, while a voluntary credit is issued to a project for a verified tonne reduced or removed. How do I avoid buying a worthless credit? Insist on registry serial numbers you can look up, ask for the methodology and vintage, and treat a price far below the market for that project type as a question rather than a bargain. { "@context": "https://schema.org", "@type": "FAQPage", "mainEntity": [ {"@type": "Question", "name": "Does one carbon credit always equal one tonne of CO2?", "acceptedAnswer": {"@type": "Answer", "text": "Yes, by definition one credit equals one tonne of CO2 equivalent. What varies is quality: how the tonne was measured, whether an independent standard verified it, and whether it was retired."}}, {"@type": "Question", "name": "What does retiring a carbon credit mean?", "acceptedAnswer": {"@type": "Answer", "text": "Retiring permanently cancels the credit on its registry and assigns the tonne to a single buyer so it cannot be resold or double counted. Until retirement, the climate claim is not complete."}}, {"@type": "Question", "name": "What is the difference between avoidance and removal credits?", "acceptedAnswer": {"@type": "Answer", "text": "Avoidance credits prevent emissions that would otherwise happen, while removal credits take carbon dioxide out of the atmosphere and store it. They should be reported separately."}}, {"@type": "Question", "name": "Who issues carbon credits?", "acceptedAnswer": {"@type": "Answer", "text": "Independent standards such as Verra and Gold Standard issue credits to projects after third-party auditors validate the design and verify the results."}}, {"@type": "Question", "name": "Can individuals buy carbon credits?", "acceptedAnswer": {"@type": "Answer", "text": "Yes, usually through a provider that aggregates and retires on their behalf, since registries are set up for institutional accounts."}}, {"@type": "Question", "name": "Are carbon credits the same as EU ETS allowances?", "acceptedAnswer": {"@type": "Answer", "text": "No. An allowance is a government-issued permission to emit within a regulated cap, while a voluntary credit is issued to a project for a verified tonne reduced or removed."}}, {"@type": "Question", "name": "How do I avoid buying a worthless carbon credit?", "acceptedAnswer": {"@type": "Answer", "text": "Insist on registry serial numbers you can look up, ask for the methodology and vintage, and treat a price far below the market for that project type as a question rather than a bargain."}} ] }

8 Sep 2026

How Do Trees Absorb CO2? The Science, Simply

Trees absorb CO₂ through photosynthesis: their leaves take in carbon dioxide from the air, use energy from sunlight and water drawn up through the roots to convert it into sugars, release oxygen as a by-product, and lock the leftover carbon away in new wood. A growing tree is essentially carbon pulled out of the sky and stored as solid trunk, branch and root — though how quickly and how much it captures depends heavily on the species, its age and the local climate. How photosynthesis captures carbon, step by step Leaves breathe in. Tiny pores called stomata open and draw carbon dioxide from the surrounding air. Sunlight powers the reaction. Chlorophyll captures light energy, which the leaf uses to split water and rearrange the carbon. Sugars are built. Carbon, hydrogen and oxygen recombine into glucose — the fuel and the building material for new growth. Oxygen is released. The oxygen left over from splitting water is returned to the air we breathe. Carbon is locked in. The tree turns those sugars into wood, so the carbon stays put for decades or even centuries. The counterintuitive part: a tree is mostly made of air Ask most people where a tree's mass comes from and they say the soil. It mostly comes from the atmosphere. The carbon in a five-tonne trunk arrived as carbon dioxide gas, one molecule at a time, through pores on the leaves. Soil supplies water and mineral nutrients, but the bulk of the structure is assembled from air and sunlight. This is why a forest works as a carbon store at all: growth is the mechanism. A tree that is not adding wood is not adding carbon, which is also why a mature, slow-growing forest stores an enormous amount while absorbing relatively little each year, and a young, fast-growing one does the opposite. Where the carbon actually goes Most of the captured carbon becomes the physical structure of the tree — the trunk, branches, bark and roots — while a meaningful share also enters the soil through fallen leaves, dead roots and the fungi living around them. Roughly half of a tree's dry weight is carbon, so a mature, heavy tree represents years of patient, compounding absorption rather than a one-off deposit. That is also why healthy soil matters as much as the canopy: undisturbed ground can hold as much carbon as the trees standing on it. The trees you can follow on your Evertreen forest keep sequestering more each year as they add wood, instead of capturing a fixed amount once and then stopping. How much CO₂ does one tree absorb? Honestly, it varies a lot. A commonly cited range is ≈ 10–40 kg of CO₂ per year for an established tree, but the real figure swings widely with species, growth rate, rainfall, soil and how much room the tree has to spread. The timing matters as much as the total: young saplings absorb very little in their first years — sometimes well under a kilogram — then accelerate sharply as their leaf area and wood volume expand, before tailing off again in old age. That early lag is why treating a freshly planted sapling as an instant 20 kg saving is misleading, and why any single one-tree-equals-a-number claim is best read as a rough long-run average, not a first-year guarantee. The sizing arithmetic is in how many trees to offset your carbon footprint. What happens to the carbon when a tree dies This is the question that separates a carbon store from a carbon sink, and it deserves a straight answer: much of it comes back. As deadwood decays, microbes break down the carbon compounds and release CO₂ back into the atmosphere. If the tree burns, the release is immediate. Some carbon does persist — in stable soil compounds, in long-lived timber products, in the next generation of trees that grow using the nutrients released. But permanence is a real constraint, not a technicality, and it is exactly why certified forestry projects hold a share of credits in a shared buffer pool against fire, disease and clearance, and why monitoring matters more than planting volume. A forest that is protected for a century stores carbon; a forest that is planted for a photograph does not. Trees versus other carbon removal Trees are cheap, immediately available, and deliver biodiversity, water and community benefits alongside carbon — but they are slow and their permanence must be managed. Soil carbon is enormous in aggregate and genuinely difficult to measure, which is why it is harder to certify. Engineered removals such as direct air capture store carbon far more durably, but cost an order of magnitude more per tonne and are limited in scale today. These are complements, not competitors. Planting is the option that is available now, at a price most organisations can act on, with visible co-benefits. How Evertreen estimates this — conservatively Rather than quoting one flattering figure, Evertreen uses a transparent method for estimating tree CO₂ that deliberately leans conservative and accounts for species and real growth over time; you can read the full approach in how we estimate tree CO₂. Because each project shares its location, progress photos and updates, the growth behind those estimates is something you can follow rather than take on trust. And if you want to size your own footprint before planting from £1.5 per tree, our free CO₂ calculator gives you a grounded, no-obligation starting point. Frequently asked questions Do trees absorb CO₂ at night? Photosynthesis needs light, so active carbon capture happens during daylight hours. At night trees respire and release a small amount of CO₂, much as we do, but across a full 24-hour cycle a healthy, established tree remains a clear net absorber. How much CO₂ does a tree absorb in a year? Often somewhere around 10–40 kg once it is well established, but this varies hugely by species, age, soil and climate, and is far lower — sometimes near zero — in a tree's first few years. Do older or younger trees absorb more? Fast-growing, established trees usually absorb the most each year because they are adding the most new wood. Very young saplings capture little at first, and very old trees slow down again, so a tree's strongest years for absorption are typically in its productive middle age. Where does a tree's mass come from? Overwhelmingly from carbon dioxide in the air, combined with water. Soil supplies water and minerals rather than the bulk of the structure. What happens to the carbon when a tree dies? Much of it returns to the atmosphere as the wood decays or burns, though some persists in soil, in timber products and in subsequent growth. This is why permanence and monitoring matter. Do forests store carbon in the soil too? Yes, and in many ecosystems the soil holds as much carbon as the trees above it, accumulated through leaf litter, dead roots and fungal networks. Which trees absorb the most CO₂? Fast-growing species in warm, wet conditions accumulate biomass quickest, and mangroves are exceptional because of the carbon locked into their sediment. The species suited to the site usually beats the fastest grower on paper. { "@context": "https://schema.org", "@type": "FAQPage", "mainEntity": [ {"@type": "Question", "name": "Do trees absorb CO2 at night?", "acceptedAnswer": {"@type": "Answer", "text": "Photosynthesis needs light, so active capture happens in daylight. At night trees respire and release a small amount of CO2, but over a full day a healthy established tree is a clear net absorber."}}, {"@type": "Question", "name": "How much CO2 does a tree absorb in a year?", "acceptedAnswer": {"@type": "Answer", "text": "Often around 10 to 40 kg once well established, varying hugely by species, age, soil and climate, and far lower in a tree's first few years."}}, {"@type": "Question", "name": "Do older or younger trees absorb more CO2?", "acceptedAnswer": {"@type": "Answer", "text": "Fast-growing established trees absorb the most each year because they add the most new wood. Very young saplings capture little and very old trees slow down again."}}, {"@type": "Question", "name": "Where does a tree's mass come from?", "acceptedAnswer": {"@type": "Answer", "text": "Overwhelmingly from carbon dioxide in the air combined with water. Soil supplies water and minerals rather than the bulk of the structure."}}, {"@type": "Question", "name": "What happens to the carbon when a tree dies?", "acceptedAnswer": {"@type": "Answer", "text": "Much of it returns to the atmosphere as the wood decays or burns, though some persists in soil, timber products and subsequent growth, which is why permanence and monitoring matter."}}, {"@type": "Question", "name": "Do forests store carbon in the soil?", "acceptedAnswer": {"@type": "Answer", "text": "Yes. In many ecosystems the soil holds as much carbon as the trees above it, accumulated through leaf litter, dead roots and fungal networks."}}, {"@type": "Question", "name": "Which trees absorb the most CO2?", "acceptedAnswer": {"@type": "Answer", "text": "Fast-growing species in warm, wet conditions accumulate biomass quickest, and mangroves are exceptional because of carbon locked into their sediment. The species suited to the site usually outperforms the fastest grower on paper."}} ] }