Updated on June 26, 2026 by Savita Bowman. Originally posted on November 18, 2021
Carbon, the sixth most abundant element found on Earth, can be released into our atmosphere in the form of carbon dioxide (CO2) and is the foundation of all life. The mechanism that balances the amount of CO2 in our atmosphere is called the carbon cycle, where carbon atoms continually travel from the atmosphere to the Earth and then back into the atmosphere. Much of the carbon on our planet is trapped in glaciers, rocks and underground sediments, while the rest is located in the ocean, atmosphere and in living organisms; in the carbon cycle, these are known as the reservoirs or sinks. Carbon can be released into the atmosphere as CO2 through a variety of both natural and man-made methods.
Strategically managing these carbon flows and leveraging carbon as a commodity is critical to U.S. energy security, industrial competitiveness and leadership in next-generation manufacturing and fuels, while also helping to reduce emissions. So, how do we capture the CO2 already in the atmosphere? There are multiple carbon dioxide removal (CDR) solutions, but before we get into those, it’s important to understand a few basics.
Carbon mitigation, encompassing both avoidance and abatement, utilizes technologies that capture or eliminate emissions at the source before they reach the air. Carbon mitigation solutions include a range of approaches, such as carbon capture, utilization and storage (CCUS) technologies to reduce emissions from power plants or industrial facilities, adding low-carbon fuel sources like nuclear or geothermal, or improving energy efficiency.
Alternatively, carbon removal refers to the process of removing CO2 that is already in the atmosphere. Carbon removal solutions range from engineered solutions such as direct air capture (DAC) and biomass energy with carbon capture and storage (BECCS) to natural solutions such as tree planting.
Think of it like a diet. You could eat healthy from the start to prevent unnecessary weight gain (mitigation), or you could fill up on all the tasty treats you want and try to work off the weight later by exercising (removal). However, any good nutritionist or personal trainer will tell you that you need both exercise and a healthy diet to live a healthy lifestyle. Similarly, businesses and nations need both mitigation and removal strategies to manage risk, stay competitive and meet evolving market demands from customers prioritizing low-carbon products.
Carbon removal is not a new concept – humans have been planting trees for years with the goal of capturing CO2 from the atmosphere. Though tree planting is one way to remove excess CO2, knowing how much CO2 is removed and how long it stays out of the atmosphere is still being researched and debated today.
Terrestrial ecosystems like forests, tropical rainforests and grasslands currently remove around 30 percent of CO2 emissions annually — that’s roughly 9.5 billion tons of CO2. There is significant room to scale these natural processes, creating new opportunities for our working lands. This potential lies in two key areas: forestry and domestic agriculture. Natural carbon removal solutions, typically having a permanence of 100 years, are lower in cost, averaging $50 or less per ton of CO2 removed. These solutions can also support rural economies and strengthen land productivity, offering benefits for landowners beyond carbon removal. For instance, forests in the United States generate more than $13 billion every year just from visitor spending.
Earth’s forests account for the vast majority of terrestrial carbon removal, removing roughly 8.8 billion tons of CO2 annually. Improved forest management, afforestation and reforestation are all considered forestry-based terrestrial natural carbon removal solutions, as there is no mechanical or chemical intervention to assist with the carbon removal process. The key difference between the three is as follows:
Soil carbon sequestration is another terrestrial natural carbon removal solution. Land management practices can be modified to increase carbon uptake of soil to result in a net removal of CO2 from the atmosphere.
Through agriculture, there are many ways to increase carbon in soils, including:
Though natural solutions are a crucial carbon removal tool, it is difficult to measure and monitor the amount of carbon removed through natural processes; therefore, scientists and researchers depend on assumptions and estimates to determine the rate of CO2 removed from the atmosphere. Additionally, with solutions such as soil carbon sequestration and forestry-based carbon removal, carbon stored in soils or plants can be released back into the atmosphere if they are disturbed (i.e. dug up, deforested, burned in a wildfire, displaced by humans moving through the area, etc.). Finally, terrestrial lands are in constant competition with developers or food supply chains due to limited space. In other words, converting farmland to forests would reduce the supply of food, space for power plants, communities, buildings and so on.
Engineered solutions provide an alternative to traditional routes like tree planting through technical intervention. Pathways like this are particularly useful as they are able to speed up the rate of CO2 removed for a fraction of the land space, in addition to increasing certainty in the amount of CO2 removed and how long it stays out of the atmosphere. Though many engineered solutions are able to remove CO2 from the atmosphere for a longer period of time, a common challenge with engineered solutions is that the cost, while coming down due to new innovations, is still often greater than natural solutions.
DAC is an engineered process that scrubs CO2 from the atmosphere like a giant air purifier. The CO2 that is collected can then be permanently stored underground in geologic formations or used to create other products such as plastics, building materials or synthetic fuels, or recover additional resources such as oil or critical minerals. These carbon utilization pathways strengthen domestic supply chain security and resource independence. DAC uses similar technology to CCUS, but the main difference is that CO2 extraction is done from the atmosphere instead of at point sources such as power plants or industrial facilities.
Carbon mineralization is a natural process where certain minerals react with CO2 in the atmosphere and turn it into a solid over hundreds, or even thousands, of years. Scientists have sped up this process by enhancing the exposure of these minerals to CO2 in the atmosphere or oceans, known as enhanced or engineered mineralization.
Engineered mineralization of CO2 can be done using mineral formations rich in alkalinity, such as basalt and peridotite, and alkaline industrial wastes, such as fly ash, kiln dust or iron and steel slag. There are three ways the reaction can occur:
Uses for carbon mineralization include enhanced mineral recovery, supporting American resource independence at a time of intense global demand for critical minerals.
Biomass is the term typically used to refer to plant material that has absorbed CO2 from the atmosphere and can be used as a fuel to produce electricity or heat. BECCS is an engineered process that captures emissions when the biomass is converted into energy to prevent those emissions from getting back into the atmosphere. From a carbon cycle perspective, it can be a net reduction of CO2 from the atmosphere. BECCS has the added benefit of producing energy while removing emissions. The captured CO2 can then either be stored underground in geologic formations or in long-lived products like concrete.
Biochar is a carbon-rich product that resembles black dirt and is created through a process called pyrolysis. Pyrolysis thermally decomposes organic materials like wood chips, plant residues, manure or other agricultural waste products at high temperatures in the absence of oxygen or gasification. This process transforms biomass into a more stable form that can sequester CO2. Because biochar is so rich in CO2, farmers and cultivators use it to increase soil fertility and crop yield, making it an economical investment beyond being a carbon management tool.
Similar to how DAC filters CO2 out of the atmosphere, direct ocean capture (DOC) scrubs CO2 from seawater through chemical separation. By lowering the carbon levels in the water, it restores the ocean's capacity to naturally absorb fresh CO2 from the atmosphere.The ocean already absorbs over 30% of global CO2 emissions, making it one of the planet's largest natural carbon sinks. Additionally, the ocean contains roughly 50 times more carbon than the atmosphere, creating a substantial reservoir that could support large-scale carbon removal if technologies can be deployed efficiently and sustainably.
Ocean alkalinity enhancement (OAE) is an engineered pathway that increases the ocean’s natural capacity to absorb and store atmospheric CO2. The process typically involves adding alkaline materials, such as finely ground minerals or alkaline compounds, to seawater. These substances increase the water’s alkalinity, enabling it to convert dissolved CO2 into stable bicarbonate and carbonate ions that can remain stored in the ocean for hundreds to thousands of years.
Coastal blue carbon refers to plants, soils and vegetation that are typically grown in coastal areas such as marshes, mangroves, wetlands and seagrass. Blue carbon ecosystems remove CO2 at ten times the rate of tropical forests and store three to five times more carbon per acre, making them an especially valuable natural carbon removal solution. Conversely, ecosystem loss releases stored CO2 back into the atmosphere, turning carbon sinks into sources, which makes their preservation particularly important for mitigating emissions. Coastal conservation and restoration also strengthens coastal resilience, protecting infrastructure and local economies by mitigating damages from storms and flooding, making them a valuable investment beyond their carbon removal and storage.
With so many carbon removal pathways emerging, it’s important to determine what makes a carbon removal solution “high-quality.” There are several factors to consider, including whether the solution requires energy, how durable it is or how long the CO2 stays out of the atmosphere, whether it can scale to extract large quantities of CO2 cost-effectively, whether the amount of CO2 can be quantified and whether the CO2 removed can be verified by a third party. To add on another layer of complexity, characteristics that make the cut can be subjective. However, for simplicity’s sake, the base-level characteristics any carbon removal pathway should be able to have are certainty in measurability, durability, verifiability and scalability using clean power or clean fuels.
Over the past several years, private industry has played a pivotal role in accelerating carbon dioxide removal (CDR) technologies, both through direct investment and the creation of early markets for carbon removal credits. Major corporations have made commitments to reach net zero emissions, such as Microsoft, and have helped catalyze demand for carbon removal by signing long-term offtake agreements to offset their emissions, including a 10-year, million ton removal deal with Liferaft, a U.S.-based biochar company. Driven by ambitious decarbonization goals like Microsoft’s, voluntary demand for carbon offsets is expected to grow 4 to 13 times by 2030, increasing the market value from an estimated $15 billion to $30 billion by 2030. Other private sector initiatives, including the $100 million XPRIZE for carbon removal and billion-dollar fundraising by firms like Climeworks, further demonstrate the increasing commercialization of and confidence in the sector. At the same time, new coalitions and market intermediaries, such as advance purchase commitments and carbon credit marketplaces and verifiers, have begun to establish more stable revenue streams for CDR providers. These developments illustrate how private sector engagement is not only driving technological innovation but also shaping the economic infrastructure needed to scale carbon removal into a potentially trillion-dollar industry.
Currently, the Office of Hydrocarbons and Geothermal Energy, Office of Critical Minerals and Energy Innovation (CMEI), Office of Science and Advanced Research Projects Agency-Energy (ARPA-E) are the main Department of Energy (DOE) offices that are working to advance CO2 removal technologies. Though there has been a flurry of new carbon removal companies in the last year, many of them have focused on DAC and are still in the early technology readiness phase. There are other pathways, particularly enhanced mineralization and biomass carbon removal, that still require more research and development in addition to DAC. Research in this space focuses on how to remove CO2 economically and impactfully at scale to avoid significant resource inputs while removing the greatest amount of CO2. Studying and testing various pathways would enable the deployment of a suite of competitive solutions.
As carbon removal remains a novel solution, cost has been a large consideration in the deployment and operation of engineered solutions in particular. Federal incentives such as the Section 45Q tax credit and the DOE’s Air Capture Prize program are crucial financial tools for the deployment and operation of DAC technologies. However, in order to incentivize the deployment of a diverse portfolio of CO2 removal solutions, a tech-inclusive structure is needed to allow other measurable and permanent carbon removal and storage pathways.
Due to the diverse range of carbon removal solutions with varying levels of technology readiness and carbon removal capacity annually, a portfolio approach is needed. As such, technologies that are able to remove CO2 with high permanence, measurability and economic viability should be prioritized.
