Top climate experts say that some geoengineering-based climate solutions may be cures worse than the disease, with severe knock-on effects that could harm people and the environment, while reducing pressure to deal with root causes directly.
These findings were published in a new paper appearing in Frontiers in Science, taking a close look at five big ideas aimed at salvaging the fragile and melting Arctic and Antarctic environments. Geoengineering solutions aim to use technology to mitigate the effects of global warming, not to deal with the root causes, but they can come with a host of political, ecological, and legal hurdles.
Five Flawed Geoengineering Proposals
“These ideas are often well-intentioned, but they‘re flawed. As a community, climate scientists and engineers are doing all we can to reduce the harms of the climate crisis—but deploying any of these five polar projects is likely to work against the polar regions and planet,” said lead author Prof Martin Siegert from the University of Exeter.
1. Stratospheric Aerosol Injections (SAI): One of the most obviously alarming ideas is SAI, which plans to essentially block sunlight by seeding reflective particles like sulfate aerosols in the sky. In theory, this would push away the solar heat that greenhouse gases trap, mitigating the warming itself. So far, only computer models have demonstrated the technique’s effectiveness.
This idea carries with it grave risks, such as depleting ozone. This entirely separate environmental concern led to a push for a significant reduction in aerosol use in the first place. Additionally, such interference could create major changes to global climate patterns, a massive concern that has been part of the change from discourse around “global warming” to “climate change.”
2. Sea Curtains/Walls: Instead of addressing the heat itself, this idea would attempt to halt increasingly warm ocean water from reaching ice shelves. It would take the form of massive, flexible, buoyant walls or curtains anchored to the seabed, acting as a barrier around glacial waters. No real-world field tests have ever been conducted on these ideas, leaving their effectiveness largely theoretical.
The most significant issues with implementing this concept are similar to those associated with any large-scale infrastructure, but with the added complexity of being located in remote polar regions. Exactly who would have the authority to erect such a project is unclear, and maintenance would be unending. Erecting these barriers could also be catastrophic to the ocean ecosystem, disrupting the migration and feeding patterns of whales, seals, and seabirds. Implementing such an idea would carry a bare minimum $80 billion price tag over ten years, which is before considering the cost of repairing any unintended side effects that the structure generates.
3. Sea Ice Management: This category involves continued maintenance efforts designed to stave off impending glacial melt. Techniques proposed for such a plan include layering seawater on top of the ice to build glaciers back up artificially and using a top scattering of glass microbeads to reflect sunlight, similar to a surface version of SAI, and thereby reducing a glacier’s temperature.
Like sea curtains, no field testing has determined the effectiveness of bead scattering for reducing ice melt. That lack of testing leads to a greater uncertainty: what may be the long-term negative consequences of darkening the ice?
4. Basal Water Removal: Moving from the surface to the underside of a glacier, this idea would pump away the water underneath the glacier. By doing so, geoengineers hope to reduce ice loss by slowing ice sheet flow.
So far, only limited drilling attempts have been made to determine the method’s effectiveness. Experts worry that the pumps themselves may damage the ice, as they require massive infrastructure, trading one environmental stressor for another. Those dangers include fuel leaks from the equipment, which can poison subglacial waters.
5. Ocean Fertilization: A final idea would involve tinkering with the oceanic ecosystem. In ocean fertilization, geoengineers suggest increasing phytoplankton blooms by seeding polar oceans with nutrients, including iron. The goal is to use the dying phytoplankton to pull carbon into the ocean depths as the microscopic creatures expire.
While researchers have performed some experiments utilizing the concept, the results were inconclusive. Exactly which organisms will thrive on the newly introduced nutrients is also difficult to predict, potentially leading to unintended ecosystem imbalances.
“If we instead combine our limited resources towards treating the cause instead of the symptoms, we have a fair shot at reaching net zero and restoring our climate’s health,” said co-author Dr Heidi Sevestre from Arctic Monitoring and Assessment Programme Secretariat.
Geoengineering Complications
The same issue plaguing real-world testing of these ideas will be present in their implementation: the harsh and remote nature of polar regions. Experts who participated in the analysis warn that, broadly speaking, all of these ideas would require personnel deployments to these areas on a scale far beyond anything that has previously been considered. The logistics and operating challenges would be immense, which experts warn that geoengineering proponents are not adequately considering. Additionally, extensive and challenging political negotiations would be required for any entity to begin work, given the international nature of the areas concerned.
Beyond the challenges of putting these ideas into action, they may simply be distractions. All of these ideas carry a strong appeal to those with a vested interest in continuing to emit greenhouse gases, while none of these solutions can likely be erected at the speed and scale required to have a meaningful effect, even if they do manage to show some efficacy.
“While research can help clarify the potential benefits and pitfalls of geoengineering, it’s crucial not to substitute immediate, evidence-based climate action for as-yet unproven methods. Crucially, these approaches should not distract from the urgent priority of reducing emissions and investing in proven mitigation strategies,” said Dr Sevestre.
“The good news is that we have existing goals that we know will work. Global heating will likely stabilize within 20 years of us reaching net zero. Temperatures would stop climbing, offering substantial benefits for the polar regions, the planet, and all lifeforms,” said Prof Siegert.
The paper, “Safeguarding the Polar Regions from Dangerous Geoengineering: A Critical Assessment of Proposed Concepts and Future Prospects,” appeared in Frontiers in Science on September 9, 2025.
Ryan Whalen covers science and technology for The Debrief. He holds an MA in History and a Master of Library and Information Science with a certificate in Data Science. He can be contacted at ryan@thedebrief.org, and follow him on Twitter @mdntwvlf.