Faced with an escalating climate crisis, the scientific community and decision-makers are frantically searching for effective methods to reduce the concentration of carbon dioxide (CO2) in the atmosphere. Alongside the necessary and drastic reduction of greenhouse gas emissions, it is becoming increasingly clear that technologies for actively removing existing CO2 from the air will also be required. In this context, an innovative approach that harnesses the power of nature, supported by modern science, is attracting growing attention: genetically enhanced agricultural crops.

Researchers from the prestigious University of California, San Diego (UC San Diego), specifically from the Scripps Institution of Oceanography and the School of Global Policy and Strategy (GPS), have presented a study suggesting that plants with genetically enhanced, significantly enlarged root systems represent a feasible and potent strategy for sequestering vast amounts of carbon dioxide from the atmosphere and storing it long-term in the soil. This agricultural method could be a key part of the solution for achieving negative emissions, necessary for climate stabilization.

The Scale of the Carbon Removal Challenge

The latest reports from the Intergovernmental Panel on Climate Change (IPCC) leave no room for doubt: for humanity to have a realistic chance of limiting global warming and avoiding the most catastrophic consequences of climate change, such as extreme weather events, mass crop failures, and the spread of diseases, it is necessary to remove between five and sixteen billion tons of CO2 from the atmosphere annually by mid-century. This monumental task comes on top of the existing imperative to stop or at least radically slow down the daily release of new amounts of greenhouse gases as soon as possible. Failure to act in time pushes the planet to the brink of irreversible changes.

Despite the urgency and enormous scale of the required Carbon Dioxide Removal (CDR), there has been a lack of realistic estimates of how quickly individual CDR technologies can be implemented and scaled up in real-world conditions. Daniela Faggiani-Dias, a climate scientist at Scripps Oceanography and UC San Diego’s Deep Decarbonization Initiative and the study's lead author, highlights precisely this gap. Her team's analysis suggests that crops with enhanced carbon storage properties could, within just 13 years of initial deployment, annually remove between 0.9 and 1.2 billion tons (gigatons) of CO2. This amount is approximately seven times greater than the total volume of CO2 offsets currently offered on the global market.

"There is a scientific consensus that we will need to significantly increase CDR capacity to achieve net-zero emissions – on top of drastically reducing our greenhouse gas emissions," emphasizes Faggiani-Dias. "However, research on how CDR can realistically be scaled – considering not only technical limitations but also the speed of diffusion and feasible pathways – is very scarce. This is precisely the novelty of our study. We provide a detailed analysis of the challenges of scaling CDR and propose a framework for assessing how quickly and to what extent new, highly uncertain technologies can be deployed. Although our analysis focuses on carbon-enhanced crops, the framework is applicable to other CDR approaches and helps identify key uncertainties in scaling potential."

Agriculture as an Unexpected Ally

Why might genetically enhanced crops have an advantage in the race against time? The UC San Diego research team compared this approach with other proposed carbon removal methods, such as Direct Air Capture (DAC) technologies, enhanced rock weathering that binds CO2, or ocean carbon capture. The conclusion is that many of these alternative strategies require the development of entirely new industries, technological processes, and infrastructure practically from scratch. Years, if not decades, are needed for testing, optimization, ensuring safety, and achieving economic viability, with the constant risk of unintended consequences.

On the other hand, genetic crop enhancement builds upon the existing, globally widespread, and highly developed agricultural industry. This industry has a long history of adopting innovations – from hybridization, through the development of fertilizers and pesticides, to modern tillage techniques and, of course, genetic modification. There is an established infrastructure for development, testing, seed distribution, and knowledge transfer to farmers. Although the focus has primarily been on increasing yields, redirecting some of these capacities towards the goal of carbon sequestration seems a significantly faster and more feasible path.

Soil: The Neglected Carbon Sink

An additional advantage lies in the soil itself. Centuries of intensive agriculture, particularly practices like deep plowing, have led to significant loss of organic carbon from arable land worldwide. Paradoxically, this depleted soil now represents a huge potential carbon sink. Plants with deeper and denser root systems not only fix more carbon through photosynthesis but also actively deposit it deeper into the soil through their roots. There, carbon can remain stored for a long time, especially in more stable forms of organic matter, effectively removing it from the atmospheric cycle. Processes like the exudation of organic compounds from roots and the decomposition of root biomass further contribute to building carbon stocks in the soil, while also improving its structure, fertility, and water retention capacity.

Historical Lessons and Scaling Potential

To estimate the realistic speed at which carbon-enhanced crops could spread, the researchers analyzed historical examples of the introduction of other agricultural innovations. They observed how much time was needed for technologies like hybrid seeds, pesticide use, improved fertilizers, or crop rotation to become widespread and what obstacles they faced.

The most similar innovation, offering the most relevant lessons, is the introduction of genetically modified (GM) crops. GM technology brought significant benefits to farmers (e.g., resistance to pests or herbicides, higher yields) and the industries supplying them with seeds and other inputs. However, its introduction was and remains accompanied by controversies, regulatory challenges, and resistance from parts of the public, which significantly affected the speed and extent of adoption.

Analyzing the history of GM crop diffusion in countries that permit them, the scientists determined that it took an average of about 11 years from the initial, early adoption phase to achieve widespread use on a significant portion of arable land. This timescale provides a basis for an optimistic assessment of the rapid scaling potential for carbon-enhanced crops as well, provided similar obstacles are overcome.

Regulatory Hurdles and Public Perception

Regulatory barriers and public perception are precisely the key uncertainty factors. Although the technology for enhancing crops for carbon may differ from classic GM crops (the focus is not necessarily on introducing genes from other species, but on enhancing the plant's natural properties), it will likely face similar regulatory frameworks and skepticism in some parts of the world. The study points out that, despite proven benefits in yield and reduced pesticide use, GM crops have to date occupied only about 13 percent of total agricultural land globally.

For carbon-enhanced crops to avoid a similar "ceiling" in diffusion, strong incentives will be needed. The study authors suggest that mechanisms like carbon credit markets, where farmers would be financially rewarded for the amount of carbon their crops store in the soil, could be key to encouraging the adoption of this practice. Transparent communication about the benefits and safety of the technology is also needed to build public trust and facilitate regulatory approval.

Part of the Broader Decarbonization Picture

Despite the promising potential, the study authors clearly emphasize that genetically enhanced crops are not a "silver bullet" that will single-handedly solve the climate crisis. Even if they reach the estimated removal potential of over a billion tons of CO2 per year, this is still only a fraction of what is globally required. This approach must be an integral part of a comprehensive strategy that includes rapid emissions reductions from all sectors (energy, transport, industry), the development and deployment of other CDR technologies, and changes in land use and consumption patterns.

Daniela Faggiani-Dias reminds us that all efforts towards carbon removal must go hand in hand with the fundamental transformation of the global economy towards low-carbon or zero emissions. The focus must remain on preventing further release of greenhouse gases into the atmosphere.

The research behind these conclusions was funded by a combination of private philanthropy through the Scripps Institution of Oceanography, funds from the Electric Power Research Institute (EPRI) through the Deep Decarbonization Initiative at UC San Diego, and the Peter Cowhey Center on Global Transformation at the UC San Diego School of Global Policy and Strategy. Experts from other institutions also participated in the study, including David Victor and Ryan Hanna from UC San Diego’s Deep Decarbonization Initiative, Jeffrey Sachnik and Yangyang Xu from Texas A&M University, Wolfgang Busch from the Salk Institute in La Jolla, California – where you can also look for accommodation, and Jack Gilbert from Scripps Oceanography.

Source: University of California