Lawrence Livermore National Laboratory contributed to this story. 

To reverse climate change, the United States needs to remove more carbon dioxide from the atmosphere than it produces. Scientists including Colorado State University Distinguished Professor Keith Paustian and members of his research team outline how it can be done – and how much it will cost – in two high-profile national reports. 

“Roads to Removal: Options for Carbon Dioxide Removal in the United States,” released Dec. 11, assesses methods for the nation to remove the greenhouse gas from the atmosphere at the gigaton scale. The report details carbon solutions down to the county level for all 3,143 counties in the United States, giving decision-makers location-specific actionable science. 

The holistic assessment was led by Lawrence Livermore National Laboratory and includes input from 68 researchers from 13 institutions. It was commissioned by the Department of Energy and received support from the ClimateWorks Foundation. 

Net-zero emissions by 2050

In 2022, the U.S. government established a goal to reach net-zero emissions of carbon dioxide by 2050, by reducing the amount of carbon emitted by U.S. economic activity, removing carbon dioxide from the atmosphere, and storing at least a billion tons of carbon per year. Roads to Removal lays out a road map to this goal and answers the question: How much CO2 is it possible to remove and at what cost? 

The report concludes that with today’s technologies, removing 1 billion metric tons of CO2 per year will cost roughly $130 billion annually by 2050, or about 0.5% of current GDP. This will require increasing the uptake of carbon in forests and on working agricultural lands, converting waste biomass into fuels and CO2, and using machines to remove CO2 directly from the air and inject it into deep geologic formations where it is permanently retained. This ensemble of lowest-cost approaches would create more than 440,000 long-term jobs and can be achieved using renewable energy sources, with currently available land and belowground geologic storage. 

“The world has waited too long to reduce greenhouse gas emissions, so now we’ve got to draw down the carbon dioxide in the atmosphere while aggressively reducing emissions as much as possible,” said Paustian, a professor of soil and crop sciences in the College of Agricultural Sciences and researcher with CSU’s Natural Resource Ecology Laboratory in the Warner College of Natural Resources. 

CSU team focused on croplands

The CSU team contributed to a chapter on carbon dioxide removal and storage in cropland soils. Using the trademarked DayCent computer model developed at CSU, they simulated about 37,000 cropland sites across the country, comparing alternate future scenarios in which agricultural conservation practices were implemented broadly to determine how much carbon dioxide could be stored in cropland soils.  

“The analysis demonstrates that immediately deployable soil carbon sequestering practices could play a significant role in a broader carbon dioxide removal strategy, while offering a host of environmental benefits,” said Amy Swan, who conducted the analysis with Paustian, Yao Zhang and Mu Hong, researchers with the Natural Resource Ecology Laboratory and Department of Soil and Crop Sciences. 

Roads to Removal identifies specific opportunities by location for soil and forest management, biomass conversion and direct air capture technologies, as well as geological resources. It provides information on various carbon dioxide removal transportation pathways, as well as regional and environmental justice considerations. These analyses will be useful for weighing alternatives and local benefits for specific projects. 

“Every geographical region has a unique story, as well as an opportunity to help take enough CO2 out of the air and meet our net-zero emissions goal by 2050,” said Lawrence Livermore National Laboratory scientist Jennifer Pett-Ridge, the report’s lead author.  

Social, economic and equity considerations

Another recent report from the National Academies of Sciences, Engineering and Medicine evaluates technologies, policies and societal factors needed for decarbonization and identifies the highest-priority actions to pursue in the next five to 20 years. “Accelerating Decarbonization in the United States: Technology, Policy, and Societal Dimensions” examines how the nation might achieve an equitable transition to net-zero carbon dioxide emissions. 

The report emphasizes the importance of engaging the public in planning new infrastructure and programs and supporting workers and communities to ensure a just energy transition away from fossil fuels. By reducing emissions, the report says the U.S. can expect improved health, more high-quality jobs and a stronger economy. 

Paustian, who was one of 20 authors, contributed expertise on land use and approaches to reduce agricultural emissions and sequester carbon in soils. 

“Land use – both agriculture and associated activities like deforestation in the tropics – collectively accounts for about 25% of global greenhouse gas emissions,” Paustian said. “By managing soils better, we can take CO2 out of the air and convert it into soil organic matter, which also makes our agricultural systems more productive and healthier.” 

Paustian coauthored a previous National Academies report on negative emissions technologies in 2019 that he said influenced the policy initiatives in the Inflation Reduction Act, the biggest climate investment in U.S. history. The law allocated $369 billion for energy security and climate change resilience, including $19.5 billion for climate-smart agriculture. 

Epicenter for climate science

As a leading expert in land use and greenhouse gas emissions, Paustian often is tapped to contribute to influential national and global assessments. Paustian and Stephen Ogle, a professor of ecosystem science and sustainability in the Warner College, served as lead authors on the Intergovernmental Panel on Climate Change’s guidelines for greenhouse gas inventories. Ogle and Paustian shared the 2007 Nobel Peace Prize with hundreds of other IPCC authors for their efforts to measure and counteract climate change. Ogle leads the annual estimate of U.S. greenhouse gas emissions from soils as part of the Environmental Protection Agency’s national greenhouse gas inventory that is reported to the UN Framework Convention on Climate Change. 

Colorado State University is a leader in climate research and education. Four CSU faculty members coauthored chapters in the Fifth National Climate Assessment, a state-of-the-science, congressionally mandated update intended to inform decision-making. The university recently launched the CSU Climate Initiative, which connects expertise and efforts across campus to address climate change. CSU also practices the climate science it develops; combined research activity and building operations at the Powerhouse Energy Campus has helped save more than 170 million metric tons of greenhouse gas from entering the atmosphere over the last two decades.  

The Roads to Removal report, along with fact sheets, maps, videos and a complete author list, is available at roads2removal.org. Read the National Academies’ Accelerating Decarbonization in the United States report here.