Researchers at the Massachusetts Institute of Technology (MIT) have unveiled significant findings regarding carbon dioxide removal (CDR) strategies, crucial for addressing climate change. Published on January 29, 2025, in the journal Environmental Research Letters, the study identifies biochar and enhanced weathering as promising additions to existing CDR methods.
With global temperatures surpassing 1.5 degrees Celsius above preindustrial levels, the urgency for effective CDR solutions has intensified. The study expands the CDR options beyond traditional methods like bioenergy with carbon capture and storage (BECCS) and afforestation, incorporating biochar—charcoal derived from plant matter—and enhanced weathering, which involves spreading finely ground rock to accelerate carbon storage.
Key findings suggest that diversifying CDR portfolios is the most cost-effective strategy for achieving net-zero emissions. This approach minimizes the adverse impacts on agriculture and energy consumption while maximizing carbon removal potential. By 2100, a diversified strategy could lead to the removal of approximately 31.5 gigatons of CO2 annually.
Lead author Solene Chiquier emphasizes the importance of this diversification, stating, "Relying on a single CDR option can exacerbate negative effects on land use and energy supply." The study indicates that while biochar and enhanced weathering are cost-competitive, direct air capture technologies remain less viable due to high costs.
Furthermore, the study underscores the need for region-specific CDR strategies, as local conditions significantly influence the effectiveness of these methods. For instance, afforestation could be particularly beneficial in regions like Brazil and Africa.
Finally, the researchers warn that delaying the implementation of these CDR strategies could lead to increased carbon prices globally, hindering efforts to meet climate goals. They advocate for immediate policy and financial incentives to expedite deployment.