Abstract

Drawing upon interviews with experts involved in mCDR research projects both academic and entrepreneurial, we highlight four thematic tensions that orient their thinking but are often unstated or left implicit in scientific and technical assessments:

1. the relevance of ‘naturalness’ as a criterion of evaluation for mCDR approaches;
2. the perceived need to accelerate research and development activities via alternative paradigms of evidence-building;
3. a framing of mCDR as a form of waste management that will, in turn, generate new (and currently poorly understood) forms of environmental pollutants; and
4. a commitment to inclusive governance mixed with difficulty in identifying specific stakeholders or constituencies in mCDR interventions.

Introduction

The prospect of deploying new technologies for carbon dioxide removal (CDR) has gained considerable attention, as reductions in greenhouse gas emissions fail to keep pace with climate stabilization targets (Intergovernmental Panel on Climate Change, 2023). (…)

Conclusions

(…) Our examination of these tensions leaves us with a number of outstanding questions.

1. If we acknowledge that mCDR cannot return oceans to a pristine or natural state, and that it inevitably introduces significant changes in marine environments, how much change to the oceans is ‘too much’?
2. If we must urgently develop an appropriate knowledge base to decide on mCDR deployment, how do we ensure that research acceleration does not occur to the detriment of understanding the full range of impacts and involving affected groups?
3. Even if we conceive of mCDR as a form of planetary waste management, how do we ensure adequate attention to understanding and mapping the material impacts and byproducts that it will generate, and what mechanisms could prevent burdening vulnerable communities with these new environmental harms?
4. Finally, who should ‘count’ as a relevant public for mCDR projects, and what should be the manner of their involvement in governance processes? None of these questions can be ‘resolved’ simply by expanding empirical research efforts, but they can be formulated with greater precision, and in ways that allow a fruitful dialogue among experts, and between them and the larger public.