Photo by Chris Marquardt
Leading polar scientists have issued a stark warning that five widely publicised geoengineering proposals for the Arctic and Antarctica are unlikely to work, could harm fragile ecosystems, and risk diverting attention from urgent emissions reductions.
The comprehensive assessment, published in Frontiers in Science, examined technological interventions proposed to delay or mitigate climate impacts in polar regions. The international team, involving experts from more than 30 organisations across six continents, concluded that none of the five schemes currently benefit from robust real-world testing and all face severe logistical, financial, environmental and governance challenges.
“These ideas are often well-intentioned, but they’re flawed,” lead author Professor Martin Siegert from the University of Exeter said. “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.”
Five interventions under scrutiny
The assessment evaluated proposals that have gained significant attention and research funding in recent years. These include stratospheric aerosol injections to reflect sunlight away from polar regions; underwater sea curtains or walls anchored to the seabed to prevent warm water from reaching ice shelves; sea ice management through pumping seawater onto ice to artificially thicken it or scattering glass microbeads to boost reflectivity; basal water removal by pumping subglacial water from beneath glaciers to slow ice sheet flow; and ocean fertilisation using nutrients such as iron to stimulate phytoplankton blooms that draw carbon into the deep ocean.
According to the researchers, each proposal faces fundamental problems. The interventions were found to lack scientific feasibility at the required scale, risk intrinsic environmental damage, require billions in set-up and maintenance costs, face major governance challenges, and lack adequate consideration of the extreme logistical difficulties of working in polar regions.
“The polar regions are among the harshest environments on Earth, where even basic logistics are extremely difficult,” Dr Alessandro Silvano from the University of Southampton said. “Implementing geoengineering at this scale would demand an unprecedented human presence in the polar regions—something far beyond what has ever been attempted.”
Environmental and ecological risks
The assessment identified specific environmental dangers for each intervention. Sea ice management carries particular ecological risks, with glass beads potentially darkening ice surfaces and water pumps requiring vast infrastructure. The Arctic Ice Project, which aimed to use glass bead technology to slow ice melt, was recently shut down after ecotoxicological tests revealed potential risks to the Arctic food web.
Basal water removal presents additional concerns. The researchers warned that a reduced flux of ice into the grounding zone could paradoxically lead to rapid glacier retreat if mass losses at the front from iceberg calving and submarine melt do not change. “A system that is already close to instability could be ‘pushed over the edge’ if the ice supply were insufficient to keep the grounding zone stable,” they wrote.
Governance challenges
The political and legal complexities of implementing polar geoengineering emerged as a major concern. Antarctica operates under an international treaty system requiring consensus among dozens of countries, and has never authorised projects at the proposed scales.
At the most recent Antarctic Treaty meeting, according to the paper, “the CEP advised the ATCM that a precautionary approach should be taken towards geoengineering activities and that, at this point, geoengineering methods in the Antarctic should not be conducted due to their unknown environmental consequences.”
Arctic interventions face different but equally daunting challenges. Most of the region falls under national jurisdictions of eight Arctic countries, including Russia. Current geopolitical tensions make coordinated action unlikely, whilst Indigenous communities whose traditional ways of life depend on polar ecosystems have already voiced strong opposition.
The false promise argument
The researchers’ central concern is that pursuit of these geoengineering proposals risks delaying the systemic changes needed to achieve net zero emissions by 2050.
“Mid-century is approaching, but our time, money, and expertise is split between evidence-backed net zero efforts and speculative geoengineering projects,” Siegert said. “We’re hopeful that we can eliminate emissions by 2050, as long as we combine our efforts towards reaching zero emissions.”
Professor Mike Bentley from Durham University expressed particular concern about the potential for these proposals to provide cover for continued fossil fuel use. “My biggest worry is that those with vested interests in continuing to burn fossil fuels will use some of these geoengineering ideas as an excuse not to take action because they perceive a solution is near. That’s simply not true. The solution is rapid and deep reductions in greenhouse gas emissions.”
The assessment emphasised that global heating will likely stabilise within 20 years of reaching net zero, with temperatures stopping their climb and offering substantial benefits for polar regions, the planet, and all life forms.
Mixed expert reaction
Whilst the assessment received broad support from polar scientists, some experts cautioned against dismissing research into climate intervention technologies entirely.
Professor Matthew Watson from the University of Bristol noted that the paper “highlights a series of concerns, felt by many, but in a very one-sided way,” arguing that stratospheric aerosol injection has been studied through natural analogues like the 1991 Mount Pinatubo eruption.
Professor Shaun Fitzgerald raised the question of who should decide whether geoengineering research proceeds. “There are many on the front line of the effects of climate change and who are least able to adapt, such as those from low lying islands in the Pacific where sea level rise from melting glaciers threatens to wipe out their countries, who deserve to be listened to,” he said.
However, Professor Anna Hogg from the University of Leeds welcomed the paper, noting that “geoengineering has received increased attention in recent years, as it sadly looks increasingly likely that it will be very difficult to meet the net zero goals by 2050.” She added that the interventions “lack evidence that they are effective in achieving their stated goals, are prohibitively costly, and would be challenging to install and govern given the geopolitical complexities of the Arctic and Antarctic.”
Broader context
The assessment comes as polar regions experience rapid change. Antarctic sea ice reached near-record lows in 2025, whilst recent studies have documented accelerating ice sheet melt and ecosystem disruption. The researchers acknowledge the urgency of the polar crisis but argue that proven emissions reduction strategies offer the most reliable path forward.
The team noted that whilst their assessment focuses on polar areas, other geoengineering ideas such as marine cloud brightening and space-based solar reflectors also need rigorous evaluation against similar criteria.