Study warns of overreliance on carbon dioxide removal in climate strategies

Study warns of overreliance on carbon dioxide removal in climate strategies
by Simon Mansfield
Melbourne, Australia (SPX) Feb 02, 2024

In a pivotal study published in Science, researchers have presented a cautionary perspective on the global reliance on carbon dioxide removal (CDR) strategies, shedding light on the significant challenges and potential adverse impacts associated with their large-scale deployment. The study, led by Alexandra Deprez of IDDRI-Sciences Po, critically assesses the current trajectory proposed by governments and industries which heavily leans on CDR to achieve the Paris Agreement climate objectives.

The findings of the paper suggest a considerable overestimation by the Intergovernmental Panel on Climate Change (IPCC) regarding the extent to which CDR technologies, specifically bioenergy with carbon capture and storage (BECCS), and afforestation, can safely contribute to meeting climate targets. This overreliance on future carbon removal, as opposed to immediate emission reduction and fossil fuel phaseout, poses significant risks to food security, human rights, and natural ecosystems. The research underscores a misalignment with the sustainable thresholds for land-based CDR methods once the implications for biodiversity and human livelihoods are factored in.

Co-author Prof. Paul Leadley from the University of Paris-Saclay emphasizes the unrealistic expectations set by the IPCC's feasible cost assessments for CDR. He points out the inherent conflict between the extensive land requirements for CDR and the imperative to preserve biodiversity, freshwater resources, and food security. According to the study, the ambitious upper limits of CDR could entail converting land three times the size of the United States for bioenergy crops or tree planting, potentially displacing over 300 million people into food insecurity.

Dr. Kate Dooley of the University of Melbourne adds to the discourse, advocating for a clear demarcation between emission reductions and carbon removals in government climate plans. She stresses the importance of restoring and maintaining natural ecosystems as part of meeting climate and biodiversity objectives, rather than relying on CDR to offset ongoing fossil fuel emissions.

The paper makes critical recommendations for policymakers and the scientific community, urging the estimation of a sustainable CDR budget that adheres to socio-ecological limits and the identification of viable pathways to 1.5C that do not depend on exceeding these thresholds. It also calls for responsible CDR governance to ensure that the limited sustainable supply is allocated to the most legitimate uses.

Furthermore, the researchers highlight the necessity for the upcoming cycle of IPCC reports to incorporate findings that adhere to sustainability limits, particularly as the world approaches the second half of a crucial decade for climate action. Alexandra Deprez concludes with a powerful message, framing the climate and biodiversity crises as interconnected challenges that cannot be solved through large-scale carbon dioxide removal alone. She advocates for a careful, scaled-down approach to CDR, combined with a rapid and just phaseout of fossil fuels, to truly meet global climate targets.

Research Report:Sustainability limits needed for CO2 removal