IPCC modeling of global emissions pathways that limit warming to 1.5° C includes large-scale deployment of commercial technologies that can remove carbon dioxide (CO2) from the atmosphere, offsetting current or past greenhouse gas emissions.
For example, direct air capture (DAC) pulls excess carbon dioxide directly from the ambient air. Bioenergy with carbon capture and sequestration (BECCS) uses biomass as a feedstock to produce electricity or fuels and captures the resulting CO2 emissions. The captured CO2 from both processes is used either as a feedstock in durable, long-lived products (such as concrete or carbon fiber) or safely stored deep underground, where it is naturally absorbed over time.
DAC combined with sequestration can achieve net-carbon removal when powered with clean energy and is easier to broadly scale up than other carbon-removal options. (For instance, BECCS’ scalability is limited by the availability of sustainable biomass.) Currently, the primary limiting factor to DAC is its high cost, which will decrease as it is deployed.
Technology Innovation Examples
DAC is an early-stage technology that pulls ambient air into a filter and uses chemical processes to remove CO2. The CO2-free air is released back into the atmosphere, while the captured CO2 can either be used in products or safely stored deep underground. There are two primary approaches to DAC: one uses a liquid-solvent technology and the other a solid-sorbent technology.
DAC can play a particularly key role in decarbonization because it is able to offset emissions from harder-to-abate sectors like energy-intensive manufacturing processes, heavy-duty transportation, and aviation.
BECCS involves capturing CO2 from biomass-fired electric power plants and biofuel production and safely storing it underground. BECCS can be a negative-emission technology if the stored CO2 is greater than the CO2 emitted during biomass production, transportation, and use. BECCS can be applied across several sectors of the economy, including electricity generation, biofuel production, and manufacturing products like steel and cement. For now, however, land-use competition between energy crops and food production represents a key barrier to the full deployment of this promising technology.
Research and Development
Federal investment in research and development (R&D) supports economic growth, drives down costs for key technologies, and promotes U.S. leadership on clean energy and climate. Investment in R&D for carbon removal technologies comes primarily from the U.S. Department of Energy’s (DOE’s) Office of Fossil Energy (FE). Further R&D for carbon removal comes from DOE’s Advanced Manufacturing Office, Bioenergy Technologies Office, Advanced Research Projects Area-Energy (ARPA-E), and its National Labs. However, current efforts have been limited in size and scope and are far from sufficient.
The federal government should establish a cross-cutting interagency effort that draws on the expertise of multiple federal agencies. Federal policymakers should also increase investment and enact programmatic reforms to ensure this effort focuses on advancing R&D for:
- Direct air capture (DAC); and
- Bioenergy with carbon capture and sequestration (BECCS).
Validation and Early Deployment
Before we can deploy promising clean energy technologies at scale, we must demonstrate and validate their cost and performance in real-world conditions. Demonstration projects reduce the economic and institutional risks of new technologies. As such, DOE should develop a robust portfolio of demonstration projects for technological carbon removal, including a near-term focus on DAC. To ease initial deployment, demonstration DAC plants should be co-located at sites that are suitable for underground carbon storage or have a demand for carbon utilization.
Federal tax credits, loan guarantees, and other fiscal incentives can help support the early deployment of DAC technologies by reducing the cost of DAC plants and driving private sector investment. Extending and expanding the existing 45Q tax credit, alongside other fiscal incentives such as loan guarantees, master limited partnerships, and private activity bonds, will accelerate the deployment of DAC.
Government purchasing power could make a substantial difference for DAC technologies that are near commercialization. Current procurement practices generally require cost-competitiveness with conventional fossil fuels, but a commitment from federal agencies—including the Department of Defense and Department of the Interior—would reduce the green premium associated with DAC-based fuels and give them a much-needed boost.
Risk-based Safety Standards
Since DAC with geologic storage is still an emerging technology for carbon removal, the federal government’s permitting process for saline storage remains slow and costly. The Environmental Protection Agency (EPA) must establish an efficient permitting process that effectively upholds local environmental safeguards. Until EPA can demonstrate that the regulatory path is efficient and predictable, investors may avoid these projects.
Permitting improvements will bring down project costs, reduce investment risks, and bolster DAC deployment. To further support carbon removal technologies, the federal government can assess geologic formations for storage suitability.
Rapid, Large Scale Deployment
Federal carbon prices should include a credit for carbon that is removed from the atmosphere using DAC and geologically stored. This can be accomplished through a carbon tax or a cap-and-trade system.
Clean Fuel Standard
A technology neutral clean fuel standard that incentivizes the use of low-GHG fuels can propel their deployment on a large scale. Likewise, the standard should be expanded to include fuels developed using carbon captured from DAC facilities. Such policies can establish an important market for DAC while reducing emissions across several sectors of the economy.