Technology that removes carbon dioxide and other greenhouse gases from the atmosphere is seen by the Dutch government, among others, as a promising way to become climate neutral.1It would also offer opportunities for green growth in our economy and society.
In the Climate Wiki on the page Wondermiddelen (Miracle Cures), we ask critical questions about this. (N.B. For references, please refer to the wiki page.)
Removing a highly diluted gas (~0.04%) such as CO₂ from the atmosphere is technically challenging, energy-intensive and expensive. Unlike renewable energy, it has no direct use. Its value is entirely socially and politically constructed. Without strong government policy, there is no profit to be made, which is why all companies involved depend on CO₂ compensation to bring this to market.
Carbon dioxide removal (CDR) involves deliberate human activities that remove CO₂ already present in the atmosphere and store it permanently in geological formations, soils, oceans or products. It includes natural methods such as afforestation and technological methods such as direct air capture with storage. CDR reduces the overall concentration of atmospheric CO₂, actively lowering greenhouse gas levels and counteracting climate change. In addition to rapidly reducing greenhouse gas emissions, the upscaling and expansion of CDR on land are urgent priorities if we are to meet the temperature target of the Paris Agreement.
There are many CDR methods for capturing and storing CO₂ with varying levels of development, cost, potential and sustainability. Each method has sustainability risks that may limit its long-term application.
Carbon Capture and Storage (CCS) captures CO₂ emissions directly from point sources such as power plants or industrial installations before the CO₂ reaches the atmosphere. The captured CO₂ is then transported and stored underground. CCS prevents new emissions from entering the atmosphere, but does not remove CO₂ that is already present in the air. Therefore, CCS is considered an emission reduction technology, not a removal technology.
Direct Air Capture (DAC) refers to technological systems that extract CO₂ directly from the ambient air, separate it and then store it (e.g. in geological formations) or reuse it (e.g. as a raw material for synthetic fuels).
The authors of an article in Frontiers in Climate (employed by the company ClimeWorks) see DAC as a valuable contribution to achieving net-zero emissions, provided that it can be scaled up to remove gigatonnes of CO₂ per year by 2050. At present, its capacity is no more than approximately 10,000 tonnes.
Carbon removal is a technology that is far from sufficiently developed to achieve net zero by 2050. It requires enormous amounts of energy that cannot be used for other useful purposes, even if renewable energy is used. It is incredibly expensive, especially given the scale required to remove carbon on a global scale.
Ken Rice calculated for his blog …and Then There’s Physics how much energy is needed to remove enough CO₂ from the atmosphere. If we want to use DAC to limit total warming to 1.5 °C, while emitting enough to reach 2.5 °C, DAC would need to use about 30% of all the electricity we will need over the next 80 years. It would be better to use this electrical energy to prevent these emissions, rather than using DAC to remove what has already been emitted later on. Due to the cumulative nature of emissions, ‘later’ is the worst option.
At the current rate, CO₂ storage capacity is expected to be around 700 million tonnes per year in 2050, only 10% of what is needed. Without a coordinated global effort and rapid policy changes, it seems unlikely that net zero targets will be achieved with carbon removal ambitions. CCS and DAC should not distract us from the truly effective approach to climate change, namely the accelerated phase-out of fossil fuels.
The question of where to store the carbon is also crucial. The planet can store much less carbon dioxide deep underground than previously thought. A new estimate suggests that geological storage space for carbon could run out as early as 2200. Moreover, there is a risk that carbon dioxide will leak from underground reservoirs and return to the atmosphere. So we cannot rely on it to meet the urgent need to slow down climate change.
Some of the places with the greatest storage potential, such as Indonesia, Brazil and some countries in Africa, could ultimately be stuck with a problem they did not cause. The researchers’ solution is clear: drastically reduce emissions now.
Discover more from Scientist Rebellion Netherlands
Subscribe to get the latest posts sent to your email.