Governments and businesses have been putting excessive faith in the future removal of carbon dioxide (CO2) from the atmosphere, rather than focusing on urgently reducing emissions and transitioning away from fossil fuels. New research published in Science highlights the dangers of this approach, revealing an incomplete understanding of the detrimental consequences of carbon dioxide removal for people, food security, and natural ecosystems. The study argues that the current estimates of carbon dioxide removal potential, as reported by the Intergovernmental Panel on Climate Change (IPCC), significantly overestimate the capacity of methods such as bioenergy with carbon capture and storage, and tree-planting, to achieve climate targets safely.
A Revised Perspective
The IPCC plays a crucial role in synthesizing the latest scientific literature to inform their reports. However, recent advancements in scientific understanding necessitate a reevaluation of carbon dioxide removal options and their alignment with sustainability goals. Lead author Alexandra Deprez from IDDRI-Sciences Po emphasizes the risks associated with relying on extensive carbon dioxide removal efforts, which could endanger food security, human rights, and natural ecosystems. The proposed scale of carbon dioxide removal could also push the boundaries of planetary limits in irreversible ways.
Unrealistic Deployment Expectations
The researchers analyzed the climate science literature behind the most recent IPCC reports and examined the pathways necessary to limit global warming to 1.5°C. They found that the thresholds for sustainable land-based carbon dioxide removal utilizing bioenergy crops, forestry, and ecosystem restoration were much lower than what the IPCC reports conveyed. When accounting for the risks to biodiversity and human livelihoods, the expectations for carbon dioxide removal deployment were significantly overestimated. Co-author Prof. Paul Leadley from the University of Paris-Saclay warns that the current estimates of technical and economic potentials should not guide the limits to carbon dioxide removal. Instead, issues such as biodiversity, freshwater usage, and food security should take precedence.
The IPCC’s latest mitigation report (AR6 WGIII) addresses the challenges of meeting the ambitious climate goals of the Paris Agreement, including identifying the technical and economic limits to carbon dioxide removal options. However, the upper end of the proposed limits for bioenergy with carbon capture and storage, and afforestation/reforestation could require an area of land exceeding 29 million km2, more than three times the size of the United States. If implemented on such a scale, this could potentially plunge over 300 million people into food insecurity, almost equivalent to the entire population of the US. Furthermore, analysis of existing climate commitments reveals that countries are planning to produce twice the recommended amount of fossil fuels by the end of the decade, and by 2060, using a land area for carbon removal close to the total global cropland available.
Co-author Dr. Kate Dooley from the University of Melbourne asserts that carbon dioxide removal, particularly into land and forests, should not be used as a legitimate offset for ongoing fossil fuel emissions. Instead, government climate plans should establish separate and transparent targets for emission reductions and removals that limit reliance on the latter. Meeting climate and biodiversity commitments should be achieved through the restoration and preservation of natural ecosystems. The paper also calls on the scientific community to provide essential guidance in informing future IPCC reports, which will be critical in shaping climate action during this decade.
The Interconnected Crises
The study underlines the interconnected nature of the climate and biodiversity crises, emphasizing that large-scale carbon dioxide removal alone will not solve either of these problems. It is crucial for governments, businesses, and scientific experts to adopt a holistic approach that focuses on reducing emissions, transitioning to renewable energy sources, and protecting natural ecosystems. Only through a comprehensive and multifaceted strategy can we effectively address the challenges posed by climate change and safeguard the well-being of both humanity and the planet.
The research sheds light on the risks associated with relying heavily on future carbon dioxide removal. It calls for a reevaluation of the current estimates and emphasizes the need to prioritize emission reductions and sustainable practices. By recognizing the limitations and potential consequences of carbon dioxide removal methods, we can develop more effective climate action plans that balance environmental, social, and economic considerations. Only through such a proactive and holistic approach can we achieve the goals of the Paris Agreement and safeguard the future of our planet.