Cheat Sheet: What you need to know from the National Academies report on carbon removal

From the Carbon180 Team

This week, the National Academies of Sciences released a new report titled, “Negative Emissions Technologies and Reliable Sequestration: A Research Agenda.” Carbon removal solutions pose a number of opportunities for the United States. These solutions can help fight climate change, provide a space for American leadership, and bring significant economic benefits. The kicker? These solutions have not yet received adequate public investment despite their significant potential. The report, conducted by the who’s who of the carbon removal space, recommends that the US Federal Government invest billions of dollars over the next few decades in an Apollo Program on carbon removal.

The full report explores the “safe” and “economic” (read: cost-effective) potential of a whole portfolio of carbon removal solutions (called negative emissions technologies or NETs in the report) and outlines the research agenda needed to realize their promise. It has a number of important takeaways for policymakers, foundations, and other folks working in this space. Our team studied the report yesterday and pulled out the most important and interesting findings, listed below:

Moral hazard, debunked: “Any argument to delay mitigation efforts because NETs will provide a backstop drastically misrepresents their current capacities and the likely pace of research progress.” (page 7) We need rapid emissions reductions and carbon removal in order to meet our climate goals. Carbon removal is not an excuse to delay action on climate. That said, several emission reduction research efforts would also support the advancement of negative emissions technologies. Policymakers and foundations should explore these synergies and utilize them to effectively allocate funding.

Sorry, no silver bullet: “However, the least expensive and least disruptive solution involves a broad portfolio of technologies, including those with positive, near-zero, and negative emissions. In addition, a broad portfolio of technologies (including multiple NETs) improves the ability to manage unexpected risks from nature and mitigation actions.” (page 2) We can’t pick a winner from the portfolio of carbon removal solutions. Every solution today has a number of significant constraints — for example, the amount of arable land, the amount of energy required — and therefore pursuing a portfolio of options is the smartest way to structure a research agenda.

Helping with the hard to scrub: “For example, few alternatives to chemical fuels are likely to exist for commercial aviation. One option for zero net aviation emissions would be deployment of $100/tCO2 NETs to capture and store 2.5 kg of CO2 for each liter of aviation fuel consumed. This will add ~25 cents per liter of fuel. This is just one example of how NETs might be conceptually bundled with emissions sources that are difficult to eliminate.” (page 2) The report explores the idea that carbon removal solutions can help “scrub” the difficult to decarbonize sectors of the economy to help fight climate change. This means that where traditional emissions reductions are too expensive or disruptive, low-cost carbon removal alternatives can help offset these remaining emissions.

Research… and more research: “Even NETs that are relatively mature will benefit from additional research to reduce costs and negative impacts and to increase co-benefits.” (page 4) While many of the land sector solutions like afforestation and improved forest management are ready for adoption today, there is significantly more research that can be done on “frontier technologies” that have not yet been deployed broadly.

Good news for food: “To the extent that many practices improve soil health and productivity, carbon removal activities could contribute towards meeting increased food and fiber demands without increasing the area of land under agriculture.” (page 80) Increasing global demand for food will be a big competitor for land in a carbon-constrained world. The more carbon-removing agricultural practices can also reduce land constraints, the better.

Forests, not all they’re chopped up to be?: Previous meta-analysis on the potential for natural carbon removal strategies (most notably Griscom et. al in PNAS 2017) concluded that forestry solutions (e.g. reforestation, afforestation, and improved forest management) have significantly larger carbon sequestration potential than presented in this NAS report. This difference likely comes down to the assumptions that inform the “practically achievable” amount of land that can be converted to forests based on how much we can intensify agriculture and shift our diets away from meat consumption. The discrepancy in assumptions between these two sources shows that even small changes in diets and agricultural productivity can significantly impact the amount of land available for forest restoration and signal that agricultural carbon sequestration may be equally as important as forest approaches.

Direct air capture closer to paying off than we had thought: “The major barrier to large-scale direct air capture is the high current cost. If made less expensive, direct air capture technologies could be scaled up to remove very large amounts of carbon.” (page 248) While direct air capture (DAC) systems are reported as costing greater than $500/t CO2 today, the report provides incredibly detailed calculations that show that DAC costs could reasonably fall to ranges between $100-$300/ton CO2 when deployed at greater scale. Furthermore, the report concludes that “to develop commercially-viable direct air capture systems, funding levels will need to shift toward development and demonstration” to bring prototypes to “early-of-a-kind” commercial projects. These commercial-scale demonstrations can offer the learning opportunities needed to cut DAC costs to the ranges presented in the study. Furthermore, the report notes that while DAC is unlikely to be deployed for non-climate co-benefits, its deployment requires significantly less land and water than other carbon removal solutions, which would leave land available for other uses and minimize potential negative impacts to biodiversity.

The US can still lead on climate: “The committee believes that its conclusions and recommendations are generally robust, simply because the economic rewards for success would be so large. This is due to the ongoing commitment by the U.S. government to reduce the contributors to climate change, as evidenced by the recently adopted 45Q rule that provides a $50/tCO2 tax credit for capture and storage, and the ongoing commitment to the Paris target by states, local governments, corporations, and other countries.“ (page 2) Surprisingly, this report argues that the United States can, and currently is, leading on climate change. With the significant economic potential outlined by this report and the proven bipartisan support for these solutions, carbon removal can provide an opportunity for the US to retain its leadership in technology development, innovation, and climate change.

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