Excessive Reliance on Carbon Removal Could Jeopardise Net Zero Goals: Oxford Law Experts Warn

A new interdisciplinary study led by researchers at the University of Oxford has warned that excessive dependence on carbon dioxide removal (CDR) technologies could undermine global efforts to meet net-zero targets and limit warming to 1.5°C under the Paris Agreement.

Published in the journal Climate Policy, the study examines how international law governs governments’ reliance on CDR — methods that remove CO₂ from the atmosphere and store it permanently, such as afforestation or engineered carbon capture — and sets out a series of legal “guardrails” intended to prevent CDR from becoming a substitute for urgent emissions cuts.

With global temperatures already reaching record highs, the authors argue that while CDR will be an essential component of climate action, betting heavily on future removals carries serious risks. Many governments, they note, are increasingly relying on speculative large-scale CDR deployment to offset continued emissions today — a strategy that could lead to dangerous overshoot of the Paris Agreement’s 1.5°C temperature goal.

Legal Duty of ‘Due Diligence’

Central to the analysis is the international legal obligation of due diligence, clarified in the International Court of Justice’s 2025 Advisory Opinion on Climate Change. This principle requires states to take all reasonable measures to prevent climate harm, guided by precaution, best available scientific evidence, and international standards — including the pillars of the Paris Agreement.

Applying this standard, the researchers conclude that governments are legally required to pursue deep and rapid emissions reductions in the near term, while adopting a precautionary approach to the uncertainties surrounding large-scale CDR.

The study finds that excessive reliance on removals violates this duty by increasing the risk of significant temperature overshoot — which states are obligated to minimise both in magnitude and duration.

Professor Lavanya Rajamani of Oxford’s Faculty of Law, a lead author of the study, said:

“In an uncertain world, some states are gambling on the future deployment of CDR techniques to meet their climate targets in place of more ambitious near-term mitigation measures. This approach risks overshooting the Paris temperature goal and causing serious, pervasive and irreversible climate harms. Our findings emphasise that near-term emissions reductions and feasible CDR strategies are not only ethical imperatives — they are legal requirements.”

Co-author Dr Rupert Stuart-Smith of the Oxford Sustainable Law Programme added that many national climate plans depend on unclear assumptions and unproven technologies.

“Legal guardrails are essential to avoid passing climate risks on to future generations and to ensure that CDR does not substitute for the emissions reductions urgently needed now.”

Guardrails on Carbon Removal

The legal framework identified by the researchers establishes both substantive and procedural constraints on how states may use CDR in their climate strategies.

Substantively, governments must:

• Prioritise emissions reductions over removals
• Ensure CDR strategies are technically and socially feasible
• Minimise environmental and social harms
• Avoid overreliance on removals carried out abroad through international credits

Procedurally, states are required to:

• Transparently disclose projected emissions and removals
• Distinguish between different types of CDR
• Clearly explain assumptions underpinning long-term mitigation pathways

The study concludes that many existing national climate plans fall short of these legal standards, relying too heavily on future removals while delaying immediate action.

Call for Realism and Transparency

According to the authors, international law already provides a clear benchmark for evaluating climate strategies. Aligning national policies with this framework will require sharper focus on near-term emissions cuts, greater transparency, and more realistic assessments of what CDR can safely deliver.

The research — titled Legal guardrails on states’ dependence on carbon dioxide removal to meet climate targets — is a collaboration between the University of Oxford, Imperial College London, Humboldt University of Berlin, the Potsdam Institute for Climate Impact Research, and Austria’s International Institute for Applied Systems Analysis.

The writer of this article is Dr. Seema Javed, an environmentalist & a communications professional in the field of climate and energy