By Alia Hassan, Director of International Policy
The Convention on Biological Diversity (CBD)’s COP16 wrapped up last weekend in Cali, Colombia, bringing solar geoengineering (SG) once again to the forefront of discussions on biodiversity and climate change. I attended the biodiversity COP to follow discussions on the decisions that had been drafted, and meet with representatives of parties to the Convention, UN bodies and observer organizations. As attention turns to the annual global climate negotiations at the UNFCCC COP29 in Baku, Azerbaijan next week, here are some key takeaways and reflections from the latest biodiversity COP.
COP16 reaffirms previous decisions on SG
The CBD has been a forerunner in considering geoengineering’s implications for biodiversity. The CBD’s precautionary approach, first established in 2010 through Decision X/33, discourages large-scale geoengineering until science can adequately address its risks to biodiversity, though it permits limited, controlled research. This precautionary principle is a key aspect of the CBD’s approach to new and emerging technologies, aiming to protect biodiversity from potential harm. Since addressing climate-related geoengineering in COP10, the CBD addressed this issue at COP11 through decision XI/20, and at COP13 with XIII/14.
The decision of COP16 reaffirms the precautionary approach toward climate geoengineering and emphasizes continuity with previous CBD decisions on this issue, in particular CBD decision X/33, XI/20, and XIII/14 that endorse a precautionary approach to climate-related geoengineering, urging countries to be cautious with geoengineering activities that may affect biodiversity. The decision reaffirms that addressing climate change should prioritize reducing greenhouse gas emissions and enhancing natural carbon sinks. It also encourages ecosystem-based approaches to climate adaptation and mitigation, which can provide biodiversity co-benefits without the uncertain impacts associated with geoengineering. Echoing decision XIII/14, the COP16 decision reaffirms the need for further transdisciplinary research to better understand SG’s potential effects on biodiversity (especially concerning marine and coastal biodiversity), ecosystems, socio-economic dynamics, and cultural issues. It also recognizes the importance of incorporating insights from indigenous and local communities in discussions on geoengineering. Finally, it encourages Parties to share information on any measures taken in alignment with the precautionary guidance established in decision X/33.
Addressing fragmented governance
The fragmentation of governance efforts across different UN bodies is an ongoing challenge in SG discussions. Moving forward, there is a need for coherence in the efforts undertaken by different UN bodies, perhaps under the auspices of the UNFCCC, which could offer a more comprehensive approach. As we look to the upcoming UNFCCC COP29 (and more realistically to COP30), following CBD’s guidance, parties could explore ways to create a unified, inclusive governance structure that prioritizes climate justice. Inclusive deliberation—bringing together diverse voices, especially from climate-vulnerable communities—will be essential to crafting a just, science-informed approach to SG governance.
Importantly, the CBD references to the broad concept of “climate geoengineering” can be misleading. Solar geoengineering and carbon dioxide removal (CDR) approaches each carry distinct risks, methods, and implications for ecosystems. This is especially relevant as CDR is moving at a much faster pace, with some techniques ready to be implemented at scale. Clearer distinctions in terminology would not only sharpen policy conversations but also help stakeholders understand the unique considerations and potential trade-offs each approach entails. This would allow decision-makers to engage in more targeted discussions about SG implications specifically, separate from CDR, which often aligns more closely with emission reduction strategies.
Final thoughts
As discussions on SG become more prominent, there are legitimate concerns over its potential impacts on biodiversity. Among other risks, solar geoengineering raises questions about unintended ecological consequences that could disrupt ecosystems in unforeseeable ways. Yet, as we consider these risks, we must also remember the undeniable threat posed by a warming world on biodiversity. Rising temperatures are already affecting species’ survival, migration, and reproduction patterns. Any discussion on SG’s risks should therefore weigh these alongside the more known harms of unchecked global warming.
The CBD has set a valuable precedent in SG governance by applying a precautionary approach. However, with climate risks intensifying, a cohesive, globally inclusive strategy is essential. As the UNFCCC COP29, COP30 and UNEA-7 approach, we have an opportunity to advance unified, justice-centered governance that responsibly addresses SG’s complex risks and ethical implications.