As the world faces the challenges of the climate crisis and critical threshold levels or tipping points may be reached soon, a disputable idea is gaining momentum as a potential solution: solar geoengineering – the deliberate reflection of sunlight to cool the planet. Advocates argue it could buy us time. Critics warn of unknown risks. Some see it as a possible emergency break if temperatures spiral out of control. Others call it a dangerous distraction that undermines meaningful climate action.
Research into solar geoengineering is advancing, including exploration of techniques such as stratospheric aerosol injection, which would involve spraying tiny reflective particles into the upper atmosphere to mimic the cooling effect of volcanic eruptions, and marine cloud brightening, which aims to enhance the reflectivity of low-lying marine clouds. While stratospheric aerosol injection is not being conducted, these technologies are being studied with increasing urgency in the global north. In the global south, however, they remain largely invisible to public discourse and policymaking.
That must change – and fast.
The global south is at the forefront of the climate crisis. Our regions are experiencing rising temperatures, extreme heat and altered rainfall patterns, which threaten health, food and water security. Wildfires, heatwaves, droughts, floods, and storms are becoming more frequent and severe; together with rising seas they exacerbate existing inequalities and pose significant challenges to development and public wellbeing.
While solar geoengineering has the potential to lower global temperatures, its effects would be unevenly distributed across different regions. Some areas might benefit, others might suffer harmful consequences, such as altered rainfall patterns or ecological shifts. Comprehensive research is needed to accurately determine who would benefit and who would suffer, and how to alleviate any adverse impacts. However, failing to do so inclusively could lead to geopolitical tensions and exacerbate climate injustice.
Including the global south in any conversation about technologies that could alter the global climate is not only urgent – it is possible
Governments in the global south face tough questions. Most haven’t taken a public stance on solar geoengineering. Research funding is scarce, and public debate is nearly nonexistent. The result? A risky silence and a growing gap in knowledge, capacity and influence.
This needs to change – urgently.
But including the global south in any conversation about technologies that could alter the global climate is not only urgent – it is possible. We are home to scientific talent and diverse worldviews that can inform global decisions about solar geoengineering. Excluding us risks repeating the colonial dynamics that have historically shaped climate policy: solutions designed for us but not with us.
There are some signs of constructive change emerging. The Degrees Initiative, for example, has begun funding scientists from the global south to study how solar geoengineering might affect their own regions. And the UK’s Advanced Research and Invention Agency is also funding researchers from the global south to explore the governance and ethics of geoengineering approaches. However, such efforts remain small and dramatically under-resourced.
We need public research on solar geoengineering led by institutions in the global south. We need research networks rooted in southern universities. We need funding that supports south-south collaboration. We also need a global governance framework that ensures equity, transparency and informed consent.
Engagement does not imply endorsement. Understanding solar geoengineering does not necessarily mean supporting its use. Instead, it means empowering ourselves to ask critical questions, assess potential benefits and risks, take part in policy discussions rooted in local realities, and challenge decisions made elsewhere.
Solar geoengineering is not a solution. It won’t stop ocean acidification or end our dependence on fossil fuels. At best, it’s a temporary bandage. The risks of unintended consequences, political misuse or abrupt termination remain huge. But ignoring it won’t make it go away. If it is ever considered as part of a planetary emergency response, we must not let it be shaped behind closed doors. Climate justice demands a transparent approach.
Any effort to correct the path of our planet after generations of polluting must be debated in the light.
Ines Camilloni is a vice-chair of the Intergovernmental Panel on Climate Change’s working group I for the seventh assessment cycle. She is a professor in the atmospheric and ocean sciences department at the University of Buenos Aires and senior researcher at the Center for Atmosphere and Ocean Research (Cima)
