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       From giant underwater curtains to scattering glass beads across the ice, these proposals to combat the impact of the climate crisis on the poles have been rejected by a group of scientists as “unimaginably expensive” and “dangerous.”
       Geoengineering methods, including the use of particulate matter to block sunlight and the use of extracted seawater to thicken ice sheets, have generated considerable controversy in the scientific community. Proponents argue that studying “emergency brake” solutions would be invaluable given the slow pace of carbon dioxide emissions reduction.
       However, a new analysis argues that proposed solutions for the polar regions are so flawed that no amount of research can solve the problems, and that these solutions only address the symptoms, not the root causes, of the climate emergency.
       Researchers argue that further study of these schemes would be a waste of time and money that could be better used to reduce emissions. Critics point out that the analysis focuses only on the negative consequences of geoengineering schemes, without comparing them to the damage caused by global warming.
       The Arctic and Antarctic are warming much faster than other parts of the Earth. Shrinking ice sheets are causing sea levels to rise, and the exposure of dark, sun-absorbing oceans is causing even greater temperature increases.
       Rob DeConto, a professor at the University of Massachusetts Amherst and one of the 42 scientists involved in the analysis, said, “These geoengineering solutions are expensive and pose enormous risks to the fragile polar environment. They also distract from the root cause of the climate crisis—the continued burning of fossil fuels—a problem we know perfectly well how to solve with existing technologies. Expecting these geoengineering solutions to make a difference is dangerous and unrealistic.”
       ”Everyone has the right to conduct research as long as it adheres to ethical and responsible principles,” said Martin Siegert, a professor at the University of Exeter who led the analysis. “But sometimes we have to think hard about how to prioritize truly effective research.”
       ”These (proposals) are simply unfeasible, especially given the need for decarbonization over the next 30-40 years. They are too large-scale to be addressed through research.”
       He stated that some researchers and foundations, as well as some companies seeking patents, are promoting these ideas with unrealistic optimism. “We hope to achieve net-zero emissions by 2050,” Segert added. “Anything that deviates from this goal will make the world less safe and less livable.”
       Sigurd said that even if global warming exceeds pre-industrial levels by 1.5 to 2 degrees Celsius, cutting emissions remains the fastest way to restore safe temperatures.
       In May of this year, the UK government announced a plan for geoengineering field experiments from the Arctic to the Great Barrier Reef, a government-funded project. Sigurd did not directly criticize the Advanced Research and Development Agency’s project, but stated, “How the UK uses its R&D and innovation funds should certainly carry equal weight with the UK’s decarbonization commitments.”
       The results of an evaluation of proposals for geoengineering projects in the polar regions were published in the journal *Frontiers in Science*. The researchers used six criteria to evaluate a range of proposals: effectiveness, cost, scale and timeframe, environmental risks, management issues, and potential false hopes. They concluded that none of the proposals passed the evaluation.
       Injecting seawater into Arctic sea ice could artificially thicken and protect it. But, as Dr. Heidi Sevist of the Arctic Monitoring and Assessment Project puts it, “This would require deploying millions of devices on drifting, fragmented ice. This is technically, logistically, and economically impractical. Furthermore, managing sea ice across national borders presents enormous challenges.”
       Sprinkling large numbers of tiny glass beads on ice may help reflect more sunlight, but Professor Stephen John of Monash University in Australia says these glass beads could be toxic to wildlife and fundamentally alter the reproduction of krill and other organisms.
       Perhaps the most well-known geoengineering solution is the injection of reflective particles into the stratosphere to block sunlight. Dr. Valérie Masson-Delmotte of the University of Paris-Saclay in France argues that such a large-scale project would need to be continued for many years to avoid the “termination shock” caused by rapid temperature rise. She also notes that even in winter, this solution would be ineffective, as the poles are perpetually in darkness.
       John stated that other ideas, such as installing a giant underwater curtain at a depth of 1,000 meters to prevent warm water from reaching the ice sheet and causing it to melt, are extremely difficult. He added that due to the extreme danger posed by giant icebergs, only one ship has successfully reached the required location so far.
       Meltwater beneath glaciers lubricates them as they descend into the ocean, prompting some researchers to propose drilling deep wells to extract this water. However, researchers suspect this would only accelerate the movement of other parts of the ice sheet.
       The final plan calls for releasing nutrients into the ocean to stimulate the growth of phytoplankton, which, when dead, will absorb carbon in the deep sea. Masson-Delmotte stated that, in addition to requiring large numbers of ships, this plan could also deplete ocean oxygen levels and harm marine ecosystems.
       Dr. Bessanne Davis of Newcastle University welcomed the new analysis: “Until now, the academic debate has been largely one-sided, focusing primarily on those who support or propose these measures. A response to this debate is long overdue.”
       Dr Phil Williamson, from the University of East Anglia, said the researchers had found “serious scientific shortcomings and clearly insurmountable management problems”.
       However, researchers in geoengineering and other fields have criticized the report. Dr. Peter Irwin of the University of Chicago (who is also the editor-in-chief of SRM360) stated, “The analysis in the report is too one-sided, highlighting the side effects, drawbacks, and potential risks of misuse of stratospheric aerosol injection. Stratospheric aerosol injection could halt global warming for several years at relatively low cost. It is not an alternative to emissions reductions, it has side effects, and it is very difficult to manage, but when used correctly, it appears to significantly reduce climate risks.”
       Dr. Sean Fitzgerald of the University of Cambridge said: “Unfortunately, we face serious environmental damage if we don’t carry out geoengineering. Therefore, we shouldn’t say we shouldn’t conduct further geoengineering research, but rather discuss the relative risks.”
       Analysts estimate that each geoengineering option would cost approximately $80 billion, but Professor Matthew Watson of the University of Bristol argues that this is still less than the cost of large-scale emissions reductions. He notes that reducing emissions to zero is “highly unrealistic,” so more information about geoengineering options is needed before completely ruling them out.
       Professor Andrew Shepherd of Northumbria University stated, “To some extent, we may need to protect the Earth’s ice sheets for future generations, so understanding how to do this safely is crucial. Our scientific community would be much stronger and healthier if geoengineering were not such a controversial topic.”