What is CDR - Carbon Dioxide Removal?

Shravane Balabasqer
January 15, 2022

What is CDR - Carbon Dioxide Removal?

The principal driver of climate change is the greenhouse effect, caused by the vast quantities of carbon dioxide (CO2) emitted as the byproduct of industrial processes, transportation, electricity generation, and other anthropogenic sources. 

Despite modern measures to reduce carbon emissions, atmospheric CO2 continues to grow by an average of 2.3ppm per year. In fact, the recent 2.6ppm jump between 2019 and 2020 was the fifth-highest yearly increase since the NOAA started recording CO2 in 1958.

As we addressed in previous posts, most measures are involved in reducing carbon dioxide emissions, such as using more sustainable processes, reducing energy consumption, or switching to materials that don’t generate so much CO2 when manufactured. However, we also showed that more recent proposed methods could actually help remove CO2 from the air—not just lower the levels at which it’s produced.

Carbon dioxide removal (CDR) is a geoengineering method of changing the Earth's atmosphere to remove carbon dioxide. Over the years, CDR has been proposed as a climate engineering technique that could act as an alternative to reducing greenhouse gas emissions. Alternatively, it can also potentially help us buy time for other mitigation strategies to take effect.

In this article, we explore carbon dioxide removal and how it can be used to help mitigate the effects of climate change.

What is Carbon Dioxide Removal?

Carbon dioxide removal is a carbon offset method involving carbon capture and sequestration. Specifically, carbon dioxide removal refers to technologies developed to remove carbon dioxide from the atmosphere to mitigate or defer global warming. These technologies are often called geoengineering techniques when used outside of typical environmental management contexts. 

The most commonly discussed carbon dioxide removal technique is Carbon Capture and Storage (CCS), which aims to capture carbon emissions during energy production, rather than release them into the atmosphere. 

There are currently no formally defined methods for carbon removal in international climate policy discussions. Although carbon removal is essential to maintaining Earth's carbon balance, its role in climate negotiations remains underdeveloped as few international requirements for carbon offset projects exist. 

How Does Carbon Dioxide Removal Work?

A carbon removal project can be implemented through several methods, including afforestation and reforestation. Methods proposed include those that directly remove the gas from the air and those that manage the carbon in biomass and biofuel. 

Biological processes use microorganisms that consume carbon dioxide and photosynthesis to sequester them in plants and soils. Meanwhile, geological methods inject carbon dioxide into underground reservoirs such as oil and gas fields, saline aquifers, or deep-sea sediments. There is also new direct air capture (DAC) technology, which extracts carbon dioxide from the atmosphere using chemical solvents.

Common Methods of Carbon Removal

When it comes to the different methods of carbon removal, there are a few ways to go about it today. 

Afforestation and Reforestation

Afforestation is the process of planting trees in an area that previously held none. Reforestation is the natural or artificial regeneration of forests on land that has been degraded or deforested. 

Trees absorb carbon dioxide as they grow, so increased forest cover results in a reduction of carbon dioxide in the air. For example, the World Economic Forum’s 1t.org initiative aims to plant, conserve, and restore a total of 1 trillion trees by the year 2030. This initiative alone could result in up to a third of the carbon reductions required to meet the targets laid out in the Paris Agreement.

Carbon Capture and Storage

Carbon Capture and Storage (CCS) is a carbon offset method that involves trapping carbon emissions from sources such as power plants, then storing it away in underground geological formations to prevent its reintroduction into the atmosphere. 

Carbon capture is often accompanied by offset is an act of reducing emissions and greenhouse gases to compensate for or negate emissions made elsewhere. Offsets are usually measured in carbon dioxide equivalent tonnes. 


Another example is Biochar, a form of carbon-rich charcoal made by heating biomass in the absence of oxygen. The carbon trapped in biochar is highly stable and can remain in the soil for centuries, unlike the carbon-neutral process of organic decomposition or biomass burning. 

This effectively makes biochar a carbon sequestration process that reduces CO2 levels in the atmosphere, while simultaneously enriching the soil.

Direct Air Capture

Lastly, Direct Air Capture refers to a variety of processes that directly extract carbon dioxide from the atmosphere, and store it safely without harming the environment. These processes typically utilize chemical compounds, such as potassium hydroxide, that bind with CO2 molecules. 

What are the Benefits of Carbon Dioxide Removal?

CDR has several positive effects on the environment, helping to both alleviate climate change and improve environmental quality in other ways. For example, CDR can help reduce the incidence or concentration of acid rain, resulting in improved water quality and a reduction in seawater acidity.

There are many potential benefits associated with CDR technologies, including:

  • Reducing the amount of carbon dioxide in the atmosphere and helping to mitigate climate change
  • Helping to stabilize the climate and preventing further temperature increase
  • Reducing ocean acidification
  • Preserving natural ecosystems and habitats
  • Supporting sustainable agriculture practices
  • Generating new economic opportunities

Disadvantages of Carbon Dioxide Removal

CDR technologies are important because they have the potential to directly remove carbon out of the atmosphere, which is often seen as preferable to reducing carbon emissions. However, their role in climate negotiations has been less developed than other methods because they may involve significant technological risks. 

One primary concern with all CDR methods is permanence—ensuring that carbon remains sequestered for a long time. Critics also argue that carbon removal could allow policymakers to delay more aggressive emissions reductions, which would have negative consequences in the long run.

Additionally, there is the risk that carbon dioxide removal could be used as a justification for continued fossil fuel development and consumption. Despite these concerns, many experts believe that carbon removal should be a part of any serious strategy for mitigating climate change.

CDR technology is currently more expensive when compared to reducing emissions, but there are a number of potential technological pathways that could bring down costs. There are also ways to minimize the risks associated with CDR deployment, including ensuring that the CO2 is permanently stored.

Carbon Dioxide Removal for Climate Solutions

Each method has its own benefits and drawbacks, so choosing the suitable method for your specific situation is essential. For example, if you're looking for a way to offset your own emissions, then planting trees is a great option. But if you're looking for a way to reduce emissions from a factory or other large-scale operation, then capturing and storing carbon dioxide might be a better choice.

No matter what method you choose, it's important to remember that carbon removal is just one part of the solution to combat climate change. We also need to reduce our emissions and invest in renewable energy sources. That being said, CDR will likely play a crucial role in helping us reach our climate goals.

Of course, reducing emissions isn’t an undertaking you can just set out to perform. You need some way of measuring your methods and determining the best approach. 

That’s where Carbon Analytics comes in—we allow you to determine your emission levels at the process level. And this helps you make decisions about where to focus your carbon dioxide emission removal or reduction efforts.

Book a demo with us today if you want to know more about making your business greener and more sustainable!

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