Five highly publicised polar geoengineering concepts are unlikely to help and could harm Antarctica and the Arctic, according to new research from an international consortium including scientists from Monash University.
The new assessment, published in Frontiers in Science, examined five of the most developed geoengineering concepts currently being considered for use in Antarctica and the Arctic.
It found the technological ‘geoengineering’ concepts, proposed to delay or address the impacts of climate breakdown in these regions, could harm ecosystems, international relations, and reduce our chances of reaching net zero by 2050.
Globally renowned Antarctic expert and Monash University Professor Steven Chown, who is also Director of the Securing Antarctica’s Environmental Future research program, said the new paper finds that the concepts are likely to cost billions of dollars, while reducing pressure on policymakers and carbon-intensive industries to reduce greenhouse gas emissions.
"In considering these five geoengineering concepts, Antarctic policymakers, at their most recent meeting, have adopted a precautionary approach to geoengineering in the region, and largely agreed that none of the five concepts outlined meet essential criteria to be considered safe, responsible and feasible,” Professor Chown said.
The five geoengineering concepts examined are:
- Stratospheric aerosol injections (SAI): Releasing sunlight-reflecting particles such as sulfate aerosols into the atmosphere to reduce the sun’s warming effect
- Sea curtains/walls: Flexible, buoyant structures anchored to the seabed that aim to prevent warm deep water from reaching and melting ice shelves
- Sea ice management: Artificially thickening ice by pumping seawater onto it, or scattering glass microbeads on remaining sea ice to increase its reflectivity
- Basal water removal: Pumping subglacial water away from underneath glaciers in an effort to slow ice sheet flow and reduce ice loss
- Ocean fertilisation: Adding nutrients such as iron to polar oceans to stimulate blooms of phytoplankton, which are microscopic creatures that draw carbon into the deep ocean when they die.
The research examined each concept against the likely scope of implementation, effectiveness, feasibility, negative consequences, cost, and existing governance frameworks that would allow timely deployment at scale.
According to the assessment:
- None of the ideas benefit from robust real-world testing.
- Each of the five ideas were found to risk intrinsic environmental damage.
- Each concept would cost at least $10 billion to set up and maintain. Among the most expensive are sea curtains, projected at $80 billion over 10 years for an 80 km structure.
- Either no governance frameworks exist, or would restrict deployment of such concepts, are largely opposed to them, or would require extensive political negotiation and the creation of new governance structures and infrastructure.
- Even if the proposals offered some benefit, none can be deployed at sufficient scale or speed to tackle the climate crisis within the limited time available.
Although the authors acknowledge the importance of explorative research, they say that continuing to pursue these five polar geoengineering concepts could shift focus from the urgent systemic change needed to cut greenhouse gas emissions.
Monash University Antarctic researcher Dr Felicity McCormack, from the School of Earth, Atmosphere and Environment, said the proposals risk splitting monetary and research resources when time is of the essence.
"Our time, money and expertise should be focussed on reaching net zero emissions,” Dr McCormack said.
"Although research can help clarify the potential benefits and pitfalls of geoengineering, it is crucial that such research does not distract from the urgent priority of reducing emissions and investing in proven mitigation strategies."
Read the paper online: doi.org/10.3389/fsci.2025.1527393
RESEARCHERS
Professor Steven Chown, Director at Monash-led Securing Antarctica’s Environmental Future research program, Professor at Monash School of Biological Sciences
Professor Andrew Mackintosh, Head of Monash School of Earth, Atmosphere and Environment, Chief Investigator at Securing Antarctica’s Environmental Future research program
Dr Felicity McCormack, Senior Lecturer at Monash School of Earth, Atmosphere and Environment, Chief Investigator at Securing Antarctica’s Environmental Future research program
ASSETS AVAILABLE
Illustrations of geoengineering proposals available here.
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