Carbon offsetting is often reduced to a simple calculation: estimate emissions, purchase an equivalent number of carbon credits, and claim that the impact has been addressed. In practice, the decision is much more complicated.
A tonne of carbon dioxide equivalent may look identical in a spreadsheet, but the project behind that tonne can be very different. Some projects prevent emissions, some reduce them, and others remove carbon from the atmosphere. Storage may last for very different periods, and the risks associated with each project can vary substantially.
For individuals and businesses trying to make more responsible climate decisions, the important question is therefore not only how many credits they purchase, but what those credits actually represent.
Offsetting should come after reduction
The most credible starting point is not buying credits. It is reducing emissions. A company can improve energy efficiency, electrify transport, redesign logistics or reduce waste. An individual can reconsider air travel, energy use, transport and consumption. These actions reduce emissions within the buyer’s own footprint.
Carbon credits can then be used to address residual emissions that cannot yet be eliminated. This distinction matters because offsetting cannot substitute for decarbonisation.
The revised Oxford Principles for Net Zero Aligned Carbon Offsetting explicitly place emissions reductions first. They also call for environmental integrity, transparency and an evolution of offsetting strategies as best practice develops.
Not all carbon credits represent the same climate action
The voluntary carbon market contains many types of projects. Some projects avoid emissions by preventing methane or other greenhouse gases from entering the atmosphere. Others generate renewable energy or improve energy efficiency. Nature-based projects can protect or restore ecosystems, while newer approaches seek to remove carbon directly from the atmosphere and store it for longer periods.
These mechanisms should not automatically be treated as interchangeable. Consider methane capture from a landfill. The project can prevent methane from being released and may also generate useful energy. Compare that with a carbon removal project designed to extract atmospheric CO₂ and store it for a long period.
Both activities may be measured in tonnes of CO₂e, but they address the climate problem in fundamentally different ways.
Why permanence matters
One of the most important developments in carbon markets is greater attention to permanence. Carbon stored in a forest, soil or wetland can be exposed to different risks from carbon stored in a geological formation or another engineered system.
This does not mean nature-based projects lack value. Ecosystem protection and restoration can provide biodiversity, water, soil and community benefits alongside climate benefits. It does mean that buyers should understand the durability characteristics of the credits they purchase.
The Oxford framework distinguishes between reductions and removals while placing increasing emphasis on removals and, over time, on more durable forms of storage. The revised Principles published in 2024 reinforce this transition.
The case for diversification
One way of dealing with differences between project types is diversification. Instead of concentrating an entire carbon portfolio in one technology or project category, a buyer can spread purchases across different mechanisms, locations and types of climate intervention.
This does not magically make every credit high quality. Due diligence remains essential.
Diversification is useful because carbon projects face different risks. A forestry project may face reversal risks associated with fire or land-use change. A technology project may face delivery, operational or scale-up risks. Different methodologies can also have different assumptions about baselines and additionality.
A diversified portfolio can therefore avoid relying excessively on one solution.
Coffset has built its current portfolio around this principle. Its impact portfolio includes projects across several Oxford categories, including emissions reductions, conservation, nature-based removals and long-lived removals.
Quality requires more than a certification logo
Certification is important, but buyers should not stop there. A useful project review should consider the methodology, baseline assumptions, additionality, monitoring, verification, permanence risks and the treatment of credits after purchase.
Transparency is especially important for individuals and smaller organisations that may not have specialist climate teams.
A platform can make this process easier by providing information about the underlying projects rather than presenting the purchase as a generic “green” product.
Coffset, for example, publishes information about its impact portfolio and the different categories of projects being supported. Its methodology also describes the emission factors used for footprint calculations and the verification standards associated with its carbon credits.
Why buying a portfolio can make sense
The idea of a portfolio is familiar in finance: diversification can reduce dependence on any individual investment.
There is a comparable rationale in carbon procurement. A buyer supporting several project types and geographies may reduce the consequences of a problem with any single project.
A portfolio also creates room for a transition over time. The Oxford Principles call for offsetting strategies to evolve, particularly toward greater use of carbon removals and more durable storage. That means a portfolio bought today does not need to have exactly the same composition as one bought several years from now.
This is particularly relevant for businesses planning for long-term climate targets.
The price of a tonne is not the whole story
Carbon credits can have dramatically different prices. It is tempting to assume that the cheapest tonne is automatically the most efficient purchase. But carbon credit prices reflect much more than the number of tonnes represented.
Project development costs, technology, certification, monitoring, geography, financing structures, supply and demand, and the expected durability of carbon storage can all influence the final price.
A €5 credit and a €50 credit should therefore not necessarily be evaluated using the same criteria as two identical commodities. The better question is what the buyer is financing and what evidence supports the claimed climate impact.
Measure first, then decide what to support
Carbon offsetting becomes more meaningful when it is connected to an actual emissions inventory. A person or organisation can first establish a baseline, identify its largest sources of emissions, and implement reduction measures. Once the remaining footprint is understood, carbon credits can be selected according to the buyer’s objectives and a broader climate strategy.
Digital tools can make that process easier for smaller organisations and individuals. Coffset’s platform combines carbon footprint calculation with access to verified carbon projects, allowing users to estimate their emissions before deciding what they want to compensate. The platform currently offers personal, travel, event and business-oriented calculations.
Carbon offsetting is evolving
The carbon market is still developing. New removal technologies are emerging, methodologies are being scrutinised, and companies are becoming more sophisticated about the difference between emissions reductions, carbon removals and claims associated with each. That evolution is a reason for caution, but also an opportunity.
A better carbon offsetting strategy does not need to promise that every tonne is identical or that purchasing credits eliminates the need for decarbonisation. Instead, it can acknowledge the limitations of today’s market while supporting projects that contribute to mitigation now and helping accelerate more durable solutions for the future.
The central principle is simple: reduce what you can, understand what you are buying, diversify where appropriate, and increasingly shift support toward credible carbon removal and durable storage.
That approach turns carbon offsetting from a one-time transaction into something more useful: a climate strategy that can improve as the market itself improves.
