Carbon Removal Explained

Think of the Earth’s atmosphere as a bathtub: the CO2 the world emits is the water filling it up. Regrettably, we’ve reached the point where there is too much water in the tub, and turning off the tap won’t solve the problem. Instead, we urgently need to pull the plug.

From carbon avoidance to carbon removal

When it was first discovered that there was too much carbon dioxide in the atmosphere and the Earth’s temperature was heating up, CO2 levels were pretty low. At the time, it could be argued that we could alleviate climate change by simply stopping adding further amounts of carbon dioxide. Unfortunately, the world wasn’t aligned with this objective, and we’ve now reached the point where the atmosphere is pre-loaded with too much CO2, causing a seemingly unstoppable climate crisis.

To go back to the bathtub comparison, turning off the tap and keeping the current level of water – or CO2 in our atmosphere – would still tip us over the point where the world heats up by over 1.5 or 2 degrees Celsius. That’s why we must implement measures that actively remove carbon dioxide from the atmosphere, reducing it from its current frightening levels.

This analogy highlights the difference between carbon avoidance and carbon removal technologies. Carbon avoidance refers to renewable energies such as solar and wind power that simply replace the use of fossil fuels and therefore stop new CO2 from entering our atmosphere. Meanwhile, carbon removal describes the few current technologies and projects that literally eliminate greenhouse gas from the atmosphere. The reality of our situation is that to achieve net-zero, carbon removal will become the most critical solution at our disposal, while the importance of carbon avoidance will diminish.

Nature-based systems vs. technology-driven solutions

To understand why carbon removal technologies are now essential, we only need to look at the facts and figures about the climate crisis. Even if all the signatories of the Paris Agreement hit their nationally determined contributions, the world will still be 35 billion tonnes of CO2 over where we need to be in terms of removals. We have a massive mountain to climb, with not long to reach the summit. We must be actively removing 10 billion tonnes of CO₂ from the atmosphere annually by the year 2050 (at the latest). From that year onwards, that figure jumps to 20 billion tonnes.

We must be actively removing 10 billion tonnes of CO₂ from the atmosphere annually by the year 2050 (at the latest).”

The handful of different carbon removal technologies currently available can broadly be split into two areas: nature-based systems and technology-driven solutions.

Nature-based systems involve enhancing natural processes, such as tree planting, which the public tends to prefer. However, they are inherently unstable and quite slow. Since they remove carbon over a very long period of time, this results in extended verification periods and a significant risk of them going wrong. Going back to tree planting, as the world’s temperature heats up, the likelihood of wildfires increases in multiple areas worldwide. Increasing tree planting means increasing the risk of adding fuel to a wildfire.

On the other side, technology-driven solutions, such as direct air capture, require significant up-front infrastructure costs. They also offer limited co-benefits, existing simply to only remove carbon from the atmosphere.

A couple of solutions sit in the middle of being nature-based and technology-driven, one being enhanced weathering. Enhanced weathering is the acceleration of natural rock weathering, a proven process that has been happening in nature for millennia.

We have a solid understanding of this natural process, including how it can be accelerated relatively simply by smashing up rocks into tiny pieces and spreading them on land. Furthermore, it’s an incredibly durable carbon removal solution, since the CO2 removed from our atmosphere through enhanced weathering gets locked out for hundreds of thousands of years. To have a natural process like enhanced weathering with very high durability of carbon removal is quite rare, making it an incredibly compelling carbon dioxide removal technology.

Enhanced weathering removes CO2 from the atmosphere and locks it out for hundreds of thousands of years.

Carbon removal with added benefits

If you imagine a Venn diagram highlighting the plus points of both nature-based systems and technology-driven solutions, enhanced weathering sits bang in the middle. That’s because the process also delivers some very meaningful co-benefits in improving the structure and nutrient cycle of soil.

Enhanced weathering comes in many different guises, with many different rock types capable of delivering this carbon removal function. At UNDO, we use basalt. While this type of rock is slightly slower in its carbon removal function than other rock types, it contains some vital plant nutrients, such as phosphorus and potassium. By spreading crushed basalt rock over degraded agricultural land, we’re adding significant benefits to the soil while removing carbon from the atmosphere. Improving soil structure also results in better water retention and, therefore, lower irrigation requirements.

The future of the carbon removal market

So how will the carbon removals market evolve over the coming years? It will be defined by the increase in organisations needing to fulfil net-zero commitments. Simply put, businesses won’t be able to meet sustainability pledges and commitments without involving carbon removal solutions. Therefore, carbon removal will become the premium product in the offsetting market, with demand growing exponentially and prices increasing until supply catches up. To successfully scale up proven technologies, such as enhanced weathering, and increase supply, massive investment to establish technology readiness and methodologies is of utmost importance.

No matter how effective their emissions reduction plan, organisations will still have a carbon footprint.

If they aren’t already doing so, organisations must immediately start thinking of implementing strategies to reduce their carbon footprint through operational changes, whether that’s over the next 10, 20 or 30 years. However, they must understand that they will still have a carbon footprint, no matter how effective a reduction plan they apply. These residual or leftover emissions will need to be addressed through carbon removal. It will be a dangerous game to set a target for reducing carbon from your business and rely on buying carbon credits alone because there is a high chance that they will all be already taken. That’s why I implore businesses to not only be active in the carbon removal market but also invest in it to assure future supply.

Forging a career in the carbon removal sector

But what about individuals? Lifestyle changes that reduce personal carbon footprints are already well known. However, what I believe is incredibly exciting for individuals is forging a career in the carbon removal sector. The global offsetting market is currently valued at US$1 billion, with McKinsey predicting an increase to US$50 billion by 2030 – that’s only eight years away. This growth shows the opportunities on offer and why people should pivot their careers and get involved in carbon removal. For the sector to succeed, I think we need to have the same brain drain into carbon removal that happened in the financial services sector in the 1990s.

Many brilliant people are already working in this space, but we need more individuals to get involved, given the expected growth and colossal investment in the pipeline. However, perhaps most importantly, it’s also a chance to do something meaningful in life. Because when you think about it – is anything more essential than the survival of our planet as we know it?

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Simon Manley

Head of Carbon

Specialising in carbon removal standards and methodologies, Simon ensures UNDO's projects generate verifiable, high-integrity carbon removal credits. His expertise is crucial in navigating the fast-evolving carbon removal sector, aligning UNDO's efforts with the global mission to mitigate climate change.