Geoengineering wird uns nicht vor der globalen Erwärmung neu retten. Neue Studie heißt | Schutz der polaren Regionen vor gefährlicher Geoengineering: Eine kritische Bewertung vorgeschlagener Konzepte und Zukunftsaussichten

Key sections of the news article:

>Their peer-reviewed research, published Tuesday, shows some of the untested ideas, such as dispersing particles in the atmosphere to dim sunlight or trying to refreeze ice sheets with pumped water, could have unintended and dangerous consequences.
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>The various speculative notions that have been floated, mainly via public relations efforts, include things such as spreading reflective particles over newly formed sea ice to promote its persistence and growth; building giant ocean-bottom sea walls or curtains to deflect warmer streams of water away from ice shelves; pumping water from the base of glaciers to the surface to refreeze it, and even intentionally polluting the upper atmosphere with sulfur-based or other reflective particles to dim sunlight.
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>Research shows the particle-based sunlight-dimming concept could shift rainfall patterns like seasonal monsoons critical for agriculture in some areas, and also intensify regional heat, precipitation and drought extremes. And the authors of the new paper wrote that some of the mechanical interventions to preserve ice would likely disrupt regional ocean ecosystems, including the marine food chain, from tiny krill to giant whales.
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>The paper counters a promotional geo-engineering narrative with science-based evidence showing the difficulties and unintended consequences of some of the aspirational ventures, he said. Most geoengineering ideas are climate Band-Aids at best. They only address symptoms, he added, but don’t tackle the root cause of the problem—greenhouse gas emissions.
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>“I think it’s fair to say that the promotion of some of these ideas have not provided a sense of just how difficult it would be,” Siegert said. “So what you get is the maximizing of the potential of doing it and minimizing the challenge of it ever happening. It becomes a sort of distorted, one-sided proposition.”
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>To assess the feasibility of five specific concepts, he said they developed a set of questions that could also apply to geoengineering proposals in areas other than the poles. In nearly every case, they found that the costs and logistics are prohibitive, and that there’s no reason to think they would be effective in protecting ice or reducing the impacts of global warming in other ways.
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>The first question, he said, is whether the idea would even work in practice. Then, it’s important to think about risks, both the obvious ones and the unexpected side effects that might come with any intervention large enough to affect the climate. Money is an obvious factor, since these kinds of projects could cost tens or even hundreds of billions of dollars.
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>The assessment shows that “no current geoengineering idea passes an objective and comprehensive test regarding its use in the coming decades,” he said.

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Journal link:

[Safeguarding the polar regions from dangerous geoengineering: a critical assessment of proposed concepts and future prospects](https://www.frontiersin.org/journals/science/articles/10.3389/fsci.2025.1527393/full)

Abstract:

>Fossil-fuel burning is heating the planet with catastrophic consequences for its habitability and for the natural world on which our existence depends. Halting global warming requires rapid and deep decarbonization to “net zero” carbon dioxide (CO2) emissions, which needs to be achieved by 2050 if warming is to remain within the limits set out by the 2015 Paris Agreement. However, some scientists and engineers claim that a mid-century decarbonization target will not be reached, and they propose that we should focus on technological geoengineering “fixes” or “climate interventions” that could delay or mask some of the impacts of global warming. They often cite the need to slow warming in polar regions because they are experiencing rates of warming higher than the global average, with severe and irreversible projected consequences both locally (e.g., on fragile ecosystems) and globally (e.g., on sea level). Several geoengineering concepts exist for polar regions, but they have not been fully examined by the polar science community, nor integrated with an understanding of polar dynamics and responses. Here, we evaluate five of those polar geoengineering concepts and highlight the significant issues and risks relating to technological availability, logistical feasibility, cost, predictable adverse consequences, environmental damage, scalability (in space and time), governance, and ethics. According to our expert assessment, none of these geoengineering ideas pass scrutiny regarding their use in the coming decades. Instead, we find that the proposed concepts would be environmentally dangerous. It is clear to us that the assessed approaches are not feasible, and that further research into these techniques would not be an effective use of limited time and resources. It is vital that these ideas do not distract from the priority to reduce greenhouse gas (GHG) emissions or from the critical need to conduct fundamental research in the polar regions.