The Complete Guide To Carbon Offsets

If you're confused about carbon offsetting, you're not alone. Misinformation and strong opinions about offsets abound, and it can be hard to know whether offsetting is the best (or the worst) action you can take to meet your net zero climate targets and promote climate change mitigation.

But as the UN confirmed, offsets are here to stay — and Sylvera is here to help you understand how they work and how to use them most effectively to help the planet.

カーボン・オフセットの究極のガイドブックです。 

カーボン・オフセットとは何ですか？

A carbon credit is not necessarily a carbon offset. A carbon credit only becomes a carbon offset when used for carbon offsetting, i.e. when it's retired to compensate for a company or individual's greenhouse gas emissions (GHGs). But carbon credits have uses other than carbon offsetting.

To understand carbon offsetting, it helps to first understand carbon footprints.

Everything you do releases carbon into the atmosphere — whether it's a Zoom meeting, buying the team lunch, or traveling to an industry event. A carbon footprint is measured by how many tonnes of carbon dioxide your lifestyle (or, in the corporate sense, your business's operations) puts into the atmosphere.

Carbon offsets act like the reverse of a carbon footprint. These projects help to either remove greenhouse gas emissions from the atmosphere or avoid additional carbon entering the atmosphere in the future. Individuals, companies, and governments can purchase carbon credits to compensate for the impact of their direct or supply chain emissions. Basically, for every tonne of carbon emitted, they can buy an equivalent tonne of carbon that's been removed or avoided to offset their own emissions.

クレジットとオフセット

The terms carbon credits and carbon offsets are often used interchangeably, but they're not quite the same thing.

A carbon credit represents one metric ton of carbon dioxide (CO2) avoided or removed from Earth's atmosphere. That's where the ‘carbon' in carbon offsetting comes from. It can also represent an equivalent amount of another greenhouse gas (GHG), measured in carbon dioxide equivalent (CO2e).

A carbon credit is not necessarily a carbon offset. A carbon credit only becomes a carbon offset when used for carbon offsetting, i.e. when it's retired to compensate for a company or individual's greenhouse gas emissions (GHGs). But carbon credits have uses other than carbon offsetting.

Carbon credits are tradeable units sold by project developers. They're created to avoid, remove, or reduce carbon emissions in the Earth's atmosphere. Said carbon emissions could be created by burning fossil fuels, cutting down trees, or many other things. Each carbon credit represents one metric ton of carbon dioxide (CO2) or an equivalent GHG that is or will be avoided or removed from the atmosphere. 

カーボン・オフセットの仕組み

If you're trying to achieve carbon neutrality, then your carbon offsetting process will work like this:

1. カーボンフットプリントの算出 組織、製品、サービスなどの温室効果ガス排出量を測定 （通常は暦年）。理想的には、事業やバリューチェーン（スコープ1、2、 3）全体から排出されるすべての排出量がここで考慮 されることになりますが、必ずしもそうとは限りません。

2. The credits are purchased: For each metric ton of CO2e, the organization purchases one carbon credit. These carbon credits are produced by carbon removal projects that remove GHGs from the atmosphere, like tree planting projects, or carbon avoidance projects that prevent GHGs from reaching the atmosphere in the first place, like renewable energy initiatives.

3. The credits are retired: The organization then “retires” or “cancels” the credits with the registry. This means that the credits cannot be traded again or claimed by anyone else, so the organization retiring the credits has the sole and permanent claim to the metric tons of Ce associated with those credits. As such, they can claim the environmental benefits as well.

If you're trying to achieve net zero, then your offsetting process will work like this:

1. カーボンフットプリントの計算

2. Aggressively reduce emissions within your operations and supply chains (with a goal to reduce emissions by 90% or more by a set date). Make more ambitious emissions cuts as the date gets closer.

3. 短期的には、残存する排出量を補うために、高品質のクレジットを購入します （ただし、事業活動によって発生する、絶対に避けられない少数の排出量に限ります）。
4. 退職単位。

カーボンオフセットの種類

There are many ways to remove carbon from the atmosphere and avoid more carbon entering the atmosphere. As such, voluntary carbon offsets fall into different categories and types.

炭素プロジェクトのカテゴリー

Broadly, carbon credit projects fall into two categories: avoidance and reduction projects, and removals projects. Avoidance projects fund activities that prevent GHG emissions that would have otherwise been emitted. Examples include nature-based projects that protect forests from deforestation, and renewable energy projects that build solar farms to eliminate reliance on fossil fuels.

There is an ongoing debate about whether avoidance or removals projects are more effective. But in reality, both are essential in the fight against climate change. According to Sylvera’s Market Intelligence,  in 2025, removals credits make up 5% of carbon credit retirements. Avoidance credits make up 80% of retirements, and mixed credits (those that are categorised as sitting between both avoidance and removal) make up the remaining 15%.

炭素プロジェクトの種類

There are a number of project types in the VCMs. They all fundamentally serve to either avoid, reduce or remove emissions, but may also have additional benefits.

‍Nature-based solutions

REDD+ (Reduce Emissions from Deforestation and forest Degradation): these projects protect existing forests from both planned and unplanned deforestation. That way, the forests can continue sequestering carbon—and the carbon stored isn't released back into the atmosphere.

ARR (Afforestation, Reforestation and Revegetation): these projects increase carbon stocks by planting or assisting the natural regeneration of woody biomass. Many ARR projects happen in developing countries, but not all of them. They can happen anywhere to help offset emissions.

IFM (Improved Forest Management): these projects increase net carbon stocks or reduce GHG gas emissions through changes in existing, or business as usual (BAU), forest management practices. The avoided emissions are then turned into offset credits to be traded on the VCM.

Jurisdictional and Nested REDD+: these are REDD+ projects that ensure all forests in a national (i.e. whole country) or subnational (e.g. state or province) jurisdiction are considered when setting a baseline and monitoring deforestation to accurately measure carbon reduction.

再生農業：これらのプロジェクトは、周辺の生態系の回復と再生を助ける農業原則を実施します。

ブルーカーボン・プロジェクト：沿岸および海洋の生態系を保護・再生するプロジェクト。

‍Technology-based solutions

再生可能エネルギー風力発電や太陽光発電など、再生可能エネルギーを送電網に追加するプロジェクト。

直接大気回収技術によって大気から炭素を直接除去するプロジェクト。

Bioenergy with carbon capture and storage (BECCS): these projects capture CO2 emissions from industrial facilities and permanently store them in geological formations underground

Biochar: these projects convert agricultural waste or biomass into stable, carbon-rich char that is applied to soils for long-term carbon storage

Cookstoves: these projects distribute efficient cooking technologies that reduce fuel consumption and emissions in households relying on traditional biomass fuels

What are some examples of carbon offset projects?

世界各地の有名なカーボン・オフセット・プロジェクトをご紹介します。

‍Katingan Peatlands

The Katingan Peatland Restoration and Conservation Project is a popular and high-quality APD project in Indonesia. This ecosystem restoration initiative is focused on a peat swamp forest in Central Kalimantan and is managed by Indonesian company PT. Rimba Makmur Utama.

Without carbon credit funding, Katingan peatlands might not exist today, as the project area was under threat of conversion before project implementation. But thanks to the conservation project, and the country's carbon crediting program, a new forest patrol and observation team have been introduced to monitor the project and implement ecosystem restoration activities.

グアテカーボン・プロジェクト

Project Guatecarbon's full name is Reduction of Emissions from Avoided Deforestation in the Multiple Use Zone of the Maya Biosphere Reserve in Guatemala. The Guatemalan project is valid for 30 years, during which time it plans to reduce 37 million metric tons of CO2e. It is a REDD+ project that aims to protect regional forests from unplanned deforestation by farmers and ranchers, agro-exporting companies, and oil companies.

グアテカーボンプロジェクトがなければ、この地域の森林資源は、森林火災に影響されるなど、既存の森林減少の要因によって破壊されていたでしょう。

シャチとマンモス, Climeworks作

The world's leading Direct-Air Carbon Capture (DAC or DACC) company is Climeworks. Climeworks runs two carbon capture projects (Orca and Mammoth) in Hellisheidi, Iceland. These direct air capture plants remove carbon dioxide from the atmosphere and store it permanently underground. To date, Climeworks has multiple well-known companies investing in its carbon removal credits, including Stripe, Microsoft, PwC, Square, and H&M.

自主的な炭素市場とは何ですか？

Carbon credits are traded on voluntary carbon markets (VCMs). Voluntary Carbon Markets are international markets that allow the sale, trade and purchase of carbon credits. Often credits are bought by emitters, including individuals and organizations, to allow them to offset their greenhouse gas (GHG) emissions. 

カーボン・オフセットは規制されていますか？

Unlike compliance carbon markets, VCMs are not currently regulated by a centralized authority, such as a government. However, stricter requirements around transparency are emerging. For example, the SEC's draft guidance on climate-related disclosures suggests that organizations using offsetting will have to disclose a range of information about the credits they have bought and retired, as well as what other actions they are taking to mitigate their climate impacts (particularly emission reductions). This will increase public scrutiny of climate strategies, opening up reputational risks for organizations with low ambition climate strategies.

There are also an increasing number of initiatives offering guidance to organizations wanting to use offsets most effectively. Most recently, the VCMI (Voluntary Carbon Markets Integrity Initiative) published a draft code of practice outlining how to use offsetting as part of a credible climate strategy.

プロジェクト開発者はどのようにしてクレジットを市場に出すのですか？

To bring credits to the carbon market, project developers must select relevant methodology from carbon certification bodies such as Verra and the Gold Standard and be validated by an auditor. These methodologies also require projects to demonstrate quality parameters such as additionality. Then, the project can appear on a carbon registry, and after that, developers monitor the project's activities to assess how many credits a project can generate once it has officially started. This monitoring report is verified by an auditor and published on the registry alongside other project documentation, and the credits are issued.

カーボン・オフセットは悪いこと？

Over the years, companies have been called out for greenwashing when using carbon offsets instead of prioritizing the more difficult task of reducing emissions from their business activities.

また、規格外のカーボン・プロジェクトが団体から投資を受け、不祥事として注目を集めた例もあります。このため、市場はリスクが高いという評判が立っていますが、結局のところ、規制のないボランタリー市場では、すべての炭素クレジットが同じように作られるわけではないことが浮き彫りになっています。

「このセクターには、植林されずに残された幻の木や、森林保護によってどれだけの炭素が削減されるかという期待を大きく膨らませたベースライン予測など、スキャンダルがつきものです。透明性の欠如、不確かな仮定の使用、不十分なプロジェクト監査によって、オフセットは詐欺師の目的地となり、その結果、誰もが苦しんでいます。- サム・ギル、Sylvera共同設立者兼社長

Although carbon offsets are imperfect, they're a crucial asset in the global transition to a greener future, and for supporting the developing world at the same time.

“If we're to have a hope of preventing catastrophic global warming, offsets must be one of several tools in our arsenal,” says Sam. “While land use is currently responsible for nearly a quarter of all global emissions, with careful stewardship it could become a carbon sink—capable of removing 20 years' worth of CO2 based on 2018 levels.”

高品質のカーボン・クレジットが、ネット・ゼロの道筋や緩和の階層に沿ったより広範な気候戦略の一環として利用される場合、オフセットは短期的な気候変動対策を強化し、世界の脱炭素化を加速するための貴重なツールとなります。オフセットだけでは気候変動を解決することはできませんが、オフセットは私たちの武器として不可欠です。

1トンのCO2をオフセットするのにかかる費用は？

自主的な炭素市場は自由市場であるため、カーボンクレジット （CO2排出量1トン）の価格は大きく変動します。カーボン・クレジットの質とは、そのプロジェクトが実際にそのプロジェクトが行うと言う量の炭素を回避・除去し、そのプロジェクトに投資しなければその炭素は回避・除去されなかったであろうという確信度のことです。

Carbon credit prices vary dramatically based on project type and quality. Right now, nature-based solutions like REDD+ projects average around $7 per credit, while ARR (afforestation, reforestation, and revegetation) projects command approximately $24, and IFM (improved forest management) credits average $16. Technology-based carbon dioxide removal (CDR) projects cost significantly more due to higher implementation costs and greater perceived durability—biochar projects average $177, while direct air capture (DAC) credits can exceed $500. 

Quality ratings directly impact pricing, with buyers typically paying an additional $5 per rating band for higher-rated ARR projects and $2 per rating band for REDD+ projects. This pricing differential reflects the market's growing recognition that high-integrity credits, verified by independent agencies, deliver more reliable carbon impact and reduce the risk of greenwashing accusations.

While many companies seek out lower-priced carbon credits, thinking that purchasing more for the same amount will make more impact on the planet, the reverse is more often the case. That's why we recommend working with a partner like Sylvera to assess the quality of your carbon credits, and if necessary, invest in fewer, high-quality credits, rather than purchasing a large number of low quality credits that don't make the impact you're looking for (and, in a worst case scenario, might see your brand accused of greenwashing).

企業のネット・ゼロ目標におけるカーボン・オフセットの位置づけは？

Using carbon credits has been a popular choice to help many companies achieve their climate goals, for a number of reasons. Unlike other approaches to corporate decarbonization, such as insetting, carbon credits provide an immediate way to make a climate contribution. The main work entails conducting proper due diligence to ensure you invest in high-quality projects. Rather than establishing their own projects, which can take years, companies can purchase carbon offsets virtually instantly through the voluntary carbon markets. 

カーボン・クレジットは柔軟性も高い。企業はオフセットを1トン単位で購入できるため、必要に応じて規模を拡大したり縮小したりすることができます。オフセットは、企業が気候変動に関する目標をより早く達成するのに役立つだけでなく、長期的な脱炭素化に注力する一方で、既存の排出量を埋め合わせることもできます。また、オフセットは、企業が気候変動への投資を多様化し、関心のあるプロジェクトのポートフォリオ全体に関与する機会を提供します。

When it comes to treating carbon credits as an investment, “the most strategic players are looking at moving upstream in the value chain and trying to secure quality supply ahead of time,” says Torsten Lichtenau, Senior Partner at Bain & Company. “Carbon credits are an asset and should be treated as such on the balance sheet.”

しかし、ネット・ゼロを主張する企業が増えれば、炭素クレジットの需要が供給を容易に上回り、コストが上昇し、気候変動へのコミットメントが一部の企業にとって財務的責任となる可能性があります。「最も先進的な企業は、おそらくバランスの取れた見方をしています。

ミティゲーション・ヒエラルキー

Carbon credits play a crucial role in the private sector's ability to accelerate the global transition to net zero, but only as part of a strategic mitigation hierarchy. According to the SBTi, “purchasing high-quality carbon credits in addition to reducing emissions along a science-based trajectory can play a critical role in accelerating the transition to net-zero emissions at the global level.”

This means that offsetting is just one piece of an effective climate strategy. Although carbon neutrality can be achieved simply by offsetting existing greenhouse gasses, net zero (an increasingly popular goal) requires that a company first reduce emissions as much as possible before offsetting.

What's the difference between carbon neutral and net zero? Carbon neutral organizations compensate for, or offset, their emissions each year by purchasing and then canceling carbon credits. Setting a net zero target means committing to reduce GHG emissions as much as possible (usually by at least 90%) by a target date (generally no later than 2050, to align with global climate goals) and “neutralizing” any remaining emissions with removals credits (not just reduction/avoidance credits). Read more →

エクイノールのカーボン・マーケット担当副社長、マーガレット・ミストリーが説明します：「エクイノールでは、緩和の階層に従っています。「まず回避し、次に削減し、他の対策が優先された場合にのみオフセットします。

At Sylvera, we recommend companies follow the mitigation hierarchy. First, avoid creating additional carbon emissions (for example, if you're hosting an event for the first time, consider doing so online). Second, reduce the emissions you're already producing (for example, invest in energy-saving appliances, switch to providers offering renewable energy, and upgrade to electric vehicles). Finally, when you've done as much as possible to avoid and reduce your company's emissions, look for high-quality carbon credits to offset the difference.

カーボンオフセットに新しい言葉は必要ですか？

The UN's COP27 report and the SBTi's Net Zero Standard recommendations on carbon offsetting echo a theme that is gaining popularity in carbon markets. Both emphasize the importance of beyond value chain mitigation (BVCM) which refers to contributing over and above the impact of your own value chains.

バリューチェーンの緩和の先にあるものとは？

Rather than simply calculating and then ‘offsetting' the carbon emissions of your company and its value chain, you must think about contributing outside of your own operations. How and where else can your company leave a lasting and positive environmental impact?

This is why some people talk about needing a new word to replace ‘carbon offsets'. Perhaps ‘mitigation contributions' or ‘carbon donations' would be more appropriate.

At Sylvera, we fully support BVCM, and we encourage companies to think less about ‘offsetting' their operating emissions to become net zero or carbon neutral, but rather a non-negotiable way for companies to contribute above and beyond to a healthier planet.

企業は炭素クレジットをどのように評価すべきでしょうか？

The lack of regulation in VCMs means the quality of a project and credit can vary greatly depending on variables such as carbon performance, additionality, permanence, and co-benefits. These are the defining attributes of whether a project is of high quality or not. To thoroughly assess a carbon project's performance requires a significant amount of time and resources. Without proper due diligence, you could invest in poorly designed, low quality projects, which do not achieve meaningful climate impact or even harm communities and could result in significant financial loss and, reputational damage.

“[At Equinor] we fully expect to be scrutinized on the offsets we use, and as such we've got very high thresholds for quality in terms of what kind of offsets we will use,” says Margaret Mistry. “The thresholds include how the offsets are verified, what type of projects they relate to, whether they're also addressing community co-benefits, biodiversity and so on.”

もしクレジットが、大気から回避または除去されたCO2e排出量1トンを確実に表すものでなければ、そのクレジットは排出量を補償するものであると主張することはできません。組織が自信を持ってこの主張を行うためには、十分なデューデリジェンスを行うことが不可欠です。

There are four key factors to consider when conducting due diligence on carbon credits

• カーボン・パフォーマンスカーボン・プロジェクトが、その炭素回避・除去活動を正確に報告しているかどうか。 プロジェクト開発者が発行するクレジットの数が、プロジェクトによって回避または除去された炭素の量と同じであることを確認します。
• 追加性特定のプロジェクトによって回避または除去される排出量が、炭素収入なしには回避または除去されなかったことを保証し、過剰クレジットのリスクを定量化します。
• 永続性回避または除去された炭素が、長期的に大気中に排出されないという確信の度合いを指します 。‍
• コベネフィット炭素プロジェクトの中には、排出削減以上の効果をもたらすものもあります。可能な限り、コベネフィットを探しましょう。

Each of these factors is extremely difficult to quantify independently, and most firms won't have the tools, infrastructure, or access to the right data to do so in-house.

Our Market Intelligence helps buyers and investors avoid fragmented data with a unified view of pricing, quality, supply and demand data that enables confident decision-making in a complex market.

Sylvera 、企業がインパクトの高い炭素クレジットに投資するのをどのように支援しています。

高品質でインパクトの大きいクレジットに確実に投資する最善の方法は、Sylveraような信頼できるパートナーと協力することです。

Sylvera's independent ratings platform was designed to give sustainability leaders, traders and asset managers confidence in the VCMs. Our carbon project reports are comprehensive and accessible, and can be used by sustainability teams to help educate board members and other key decision-makers about specific carbon credit investments, their potential impact, and how to best manage the risks associated with the VCMs.

With Sylvera's carbon intelligence platform, you can:

• Save time and money on due diligence, and protect your organization's reputation
• 市場全体を俯瞰し、品質と価格を横並びで比較することで、誤った投資や機会損失を避けることができます。
• カーボン・オフセット・プロジェクトの実績とリスクを継続的にモニタリング

Sylvera's mission is to be a source of truth for carbon markets. We help corporate sustainability leaders, carbon traders and asset managers confidently evaluate and invest in the best carbon credits by providing comprehensive and accessible insights on carbon projects.

私たちの特徴は？

Project-type-specific frameworks: We build rigorous frameworks and production systems for every project category to accurately test project design, carbon accounting, and climate impact claims. Sylvera's frameworks are peer-reviewed by a committee of experts and carbon market stakeholders – including project developers & registries – to ensure scientific consensus. We publish our frameworks so buyers understand exactly what we test and how we do it. Read our white paper for more information.

圧倒的な深さと正確さ：プロジェクト設計文書（PDD）とすべてのモニタリング報告書からデータを抽出、洗浄、整理します。そして、排出削減または除去の主張を検証し、プロジェクトの経済性を評価するために、炭素、ベースラインの強さ、財務的追加性モデルを一から丹念に構築します。当社のプロジェクト評価は、市場で最も包括的であり、中核的なプロジェクト特性の詳細な分析、洞察に満ちたデータの視覚化、インタラクティブなマップを提供します。

Sylvera 、機械学習モデルの訓練と実行に複数の種類のデータを利用しています。それぞれ異なるデータを提供することで、特定の特徴を検出することができます。

独立したデータ検証：当社の専門アナリストは、高度な機械学習（ML）技術、検証済みの独立データ、および独自のフィールドデータを活用して、クレジット発行やクレームの正確性を検証します。例えば、自然ベースのソリューションを格付けする際には、市場をリードする地理空間MLモデルを使用しています。

Need help investing in high-impact carbon credits? Request a demo today.