Carbon removal and carbon capture matter because somewhere between 15–40% of the carbon dioxide that humanity emits will remain in the atmosphere for up to a thousand years, with roughly 10– 25% of it persisting for tens of thousands of years. Removing and sequestering that carbon dioxide could permanently reduce climate risk by slowing or even reversing climate change.
There is a critical difference, however, between carbon removal and carbon capture: carbon capture prevents carbon from reaching the atmosphere and carbon removal removes carbon after it is already in the atmosphere.
Carbon capture and storage (CCS) captures carbon dioxide released by burning fossil fuels from a smokestack or flue, such as in a coal-fired power plant or a cement factory, before it is released into the atmosphere. It is then put into long-term storage –sequestering that carbon dioxide underground. There are three steps:
This prevents that fossil carbon from entering the atmosphere, but it does not directly reduce atmospheric carbon dioxide levels.
Carbon capture, use, and storage technologies (CES) could capture more than 90% of carbon dioxide (CO2) emissions from power plants and industrial facilities. It is important to remember, however, that there are only 22 CCS facilities currently operating in the United States with the capacity to capture 0.4% of the nation’s total annual CO2 emissions. As of spring 2024, there are 1007 carbon capture projects in the world. Of these, a total of 228 capture plants are currently in operation, compared to 51 in 2019 and 194 large scale CCS facilities globally in 2022.
Carbon capture, utilization, and storage (CCUS) also captures carbon as described above but recycles it into short-lived products, such as synthetic fuel or food and beverages. Once again, it does not directly reduce atmospheric carbon dioxide levels. Startups have explored reusing captured carbon in novel ways like jet fuel and automobile seats, and also in the production of “blue hydrogen,” which can support the decarbonization of industry, trucks, and ships.
Carbon removal, also known as carbon dioxide removal (CDR) is the process of capturing carbon dioxide (CO2) from the atmosphere and locking it away for decades or centuries in plants, soils, oceans, rocks, saline aquifers, depleted oil wells, or long- lived products like cement.
Processes that only capture CO2 from fossil fuel consumption do not count as carbon removal, regardless of what they do with the carbon, because they are not removing the CO2 that is already in the atmosphere. The U.S. will need 2 gigatons of carbon removal annually in order to meet a target of net-zero emissions.
There are varying approaches to carbon removal, each with their own tradeoffs, costs, local benefits or negative impacts, and stages of technology development. Some methods include: tree and forest management (reforestation, restocking, silvopasture, cropland agroforestry, urban reforestation); farms and soils (cover crops, composting, grazing management); biomass carbon removal and storage (from plants or algae); direct air capture (DAC); carbon mineralization; and ocean-based approaches.
One approach to carbon removal leverages the ocean’s natural capacity as a carbon sink. Marine carbon dioxide removal (mCDR) is still in the very early stages of funding and research, and more work needs to be done to ensure these technologies will not have adverse impacts on the ocean. Methods include the intentional sinking of seaweed, artificial downwelling and upwelling, coastal wetland restoration, nutrient fertilization, and ocean alkalinity enhancement. In 2023, the U.S. developed an Ocean Climate Action Plan and put forth $24 million in funding for mCDR research projects - it is unclear if this work will continue under the Trump administration. There are currently 45 research trials in mCDR globally.
Under the Biden administration, the Inflation Reduction Act and the Bipartisan Infrastructure Law included the “largest support for carbon capture to date.” The Bipartisan Infrastructure Law included $12 million in carbon removal investments, including funding for 4 new DAC hubs, a DAC technology prize competition, carbon storage testing, geologic carbon sequestration research, and a forest restoration program. The Inflation Reduction Act provided $2 billion for natural CDR, and expanded section 45Q tax credits, initially created in the Energy Improvement and Extension Act of 2008.
Meanwhile, the Trump administration’s approach to carbon capture and removal has been summed up as “incoherent” and “disjointed.” While the 45Q tax credit was expanded further under the One Big Beautiful Bill Act, the Trump administration has also frozen or rescinded much of the federal funding provided under the IRA and the Bipartisan Infrastructure Law, proposing to reduce CDR funding in the annual budget from 70 million to 4 million. Three carbon removal projects in Louisiana, Illinois, and California are now “dead” after losing $16 million in funding from the federal government, and the startup behind the projects is relocating pilot plants to Canada. The DOE terminated 24 awards worth $3.7 billion for carbon capture and storage projects, and applications are down 55% for new projects in the U.S. The uncertainty created by the Trump administration’s muddled approach is undermining the U.S.’s status as a leader in carbon dioxide removal.
Critics warn that CCUS and CDR should not be a substitute for cutting greenhouse gas emissions. The viability of the technology at scale is still uncertain, and the results are still relatively miniscule: only around 0.1% of global carbon emissions are currently captured and stored underground or reused. Some climate activists claim investing in CCUS and CDR is “greenwashing,” as it allows for the continued operation of existing plants, an excuse to delay shuttering plants and transitioning to cleaner energy, and prolonging dependence on fossil fuels. The fossil fuel industry has supported carbon-capture, which critics say reveals the motivation behind this technology is not climate mitigation or adaptation, but profit.
Communities are protesting the building of new pipelines for carbon dioxide transport, which have environmental and public safety risks. After a carbon dioxide pipeline ruptured in Mississippi in 2020, 45 people were hospitalized, and residents are still experiencing health issues and poisoning.
An investigation by WIRED into one carbon removal startup, Running Tide, is a case in point for the dangers of profit-motivated technofixes: the startup sold 2.8 million tonnes of carbon-removal credits to Microsoft with technology that didn’t work, and in fact might have only further harmed the environment by dumping pollution into the ocean.
Measurement, reporting and verification (MRV) standards are key for responsible CDR projects, with a focus on local impacts. It is important to ask who is profiting from any given carbon removal project, and to investigate if and how each new project will intensify reliance on fossil fuels, and exacerbate environmental injustices.
CREDIT: AMERICAN UNIVERSITY (AU)
