Carbon dioxide (CO2) emitted into the atmosphere remains there for hundreds of years. As we know, this significantly impacts our climate: the enduring presence of CO2 contributes to the warming of our planet, which manifests through more frequent and severe weather events, rising sea levels and disruptions to ecosystems. The persistence of CO2 in the atmosphere makes it a critical factor in ongoing climate change, even as the world works to reduce new emissions.
Reducing carbon emissions is just half the battle
While reducing emissions is essential to mitigating climate change, it’s not enough to limit global warming to below 1.5°C. This is the threshold scientists as well as international bodies such as the IPCC consider crucial to avoid the most catastrophic impacts of climate change. Even with aggressive reductions in CO2 emissions, existing CO2 in the atmosphere will continue to drive global temperatures ever higher. Therefore, strategies that actively remove CO2 from the atmosphere must complement emission reduction efforts.
Carbon Dioxide Removal (CDR) technologies play a crucial role here. These technologies capture and store already emitted CO2 in a way that prevents it from contributing to global warming, effectively reversing some of the damage caused by past emissions.
A promising approach within the realm of CDR comes from German start-up Carbonsate. Their solution is inspired by natural processes, such as trees absorbing carbon during photosynthesis and storing it in their biomass. However, instead of being stored in trees, Carbonsate stores CO2 underground in the form of woody biomass. This prevents its decomposition and removes it from the carbon cycle for a certified duration of 100 years. However, according to Fabian Sperling, Co-Founder and CTO of Carbonsate, “our technology can store it safely for more than 1,000 years”.
This woody biomass is made from invasive trees and bushes that need to be removed from ecosystems, meaning local ecosystems are sustained rather than harmed. Wood, when preserved correctly, can stave off decomposition for a very long time, making it an ideal candidate for carbon storage. Sperling agrees; “archaeological sites have shown that wood can be conserved for thousands of years if the right conditions are created.”
What’s more, Carbonsate’s solution doesn’t rely on taking up swatches of land, but, once the initial storage chamber is built, can blend in with its surroundings. “We can store over 20,000 tonnes of CO2 on one hectare (100×100 metres) of land. The land can be used for a variety of purposes after our storage projects, for example for solar parks, agriculture, animal grazing and nature restoration.”
The process is then monitored in real-time and certified by carbon crediting program Puro.earth, which adds an extra carbon removal credit incentive for companies. And, with projects in Germany, Bulgaria, Colombia and Namibia, Carbonsate’s vision is worldwide. The pilot projects in Namibia and Colombia in particular “each already store around 500 tonnes of CO2”. The total global potential, if the calculations are correct, could be huge. According to Sperling, “fixing it to an exact number is difficult but at least two gigatonnes of CO2 can be captured when at scale. In Germany alone, the storage of wood that is currently burned could compensate for about 25 percent of all remaining emissions in 2040.”
Is Carbonsate overcompensating? CDR technologies draw scepticism
However, there has long been discussion about the usefulness of carbon dioxide removal (CDR) technology. Some argue that the growing hype around carbon dioxide removal could lead to a dangerous over-reliance on these technologies. This focus could, it’s argued, detract from the more critical need to reduce greenhouse gas emissions directly. The concern is that CDR could be seen as a “silver bullet,” causing policymakers and industries to delay essential emission reductions.
Likewise, carbon credits have met their fair share of judgement. Carbon credits are permits that allow organisations or countries to emit a certain amount of carbon dioxide or other greenhouse gases. The idea behind them is to provide economic incentives for reducing emissions by allowing entities that can easily reduce emissions to sell their excess reductions to those that find it more challenging. However, a 2023 investigation by The Guardian found that over 90 percent of carbon credits sold by the world’s largest carbon offsetting certifier were totally ineffective. In 2017, the European Commission also found that 85 percent of carbon credits purchased from the UN’s Clean Development Mechanism (CDM) by the EU didn’t actually reduce emissions.
ForTomorrow – How Stockpiling CO2 Emissions Could Help the Climate
We have to drastically reduce global CO2 emissions in the next few years if we are to achieve the Paris climate targets. A young startup from Germany believes that buying up those emissions could help us achieve that goal.
While Carbon Dioxide Removal (CDR) technologies like those developed by Carbonsate present a promising approach to addressing the persistent challenge of existing CO2 in the atmosphere, it’s helpful not to view them as a replacement for pointed emission reduction efforts. The scepticism surrounding CDR technologies and carbon credits highlights the need for a balanced strategy that prioritises direct emission reductions while investing in reliable and verifiable carbon removal solutions. As these technologies are refined over time, we argue that they could certainly have a place in a broader, multifaceted approach to climate action.
