Arctic geoengineering

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Arctic sea ice coverage as of 2007 compared to 2005 and also compared to 1979-2000 average 2007 Arctic Sea Ice.jpg
Arctic sea ice coverage as of 2007 compared to 2005 and also compared to 1979-2000 average

Arctic geoengineering is a type of climate engineering in which polar climate systems are intentionally manipulated to reduce the undesired impacts of climate change. As a proposed solution to climate change, arctic geoengineering is relatively new and has not been implemented on a large scale. It is based on the principle that Arctic albedo plays a significant role in regulating the Earth's temperature and that there are large-scale engineering solutions that can help maintain Earth's hemispheric albedo. [1] According to researchers, projections of sea ice loss, when adjusted to account for recent rapid Arctic shrinkage, indicate that the Arctic will likely be free of summer sea ice sometime between 2059 and 2078. [2] Advocates for Arctic geoengineering believe that climate engineering methods can be used to prevent this from happening. [2] [ better source needed ]

Contents

Current proposed methods of arctic geoengineering include using sulfate aerosols to reflect sunlight,[ citation needed ] pumping water up to freeze on the surface, and using hollow glass microspheres to increase albedo. These methods are highly debated and have drawn criticism from some researchers, who argue that these methods may be ineffective, counterproductive, or produce unintended consequences. [3]

Background

The rapid decline of Arctic sea ice has drawn attention to feedback loops that could accelerate global warming and has motivated proposals for climate intervention.

The Arctic's albedo plays a major role in regulating how much solar radiation is reflected away from Earth's surface. [1] As sea ice melts and the region's albedo decreases, less sunlight is reflected, causing additional warming. [1] This creates a positive feedback loop, known as the ice-albedo feedback loop, where rising temperatures cause further ice loss. [4] If this process continues, it could push the climate system past critical tipping points. [4]

Melting Arctic ice may also release methane, a powerful greenhouse gas stored in permafrost as methane clathrate. [5] Methane release could drive additional warming, creating another feedback loop. [6] A 3 °C rise above pre-industrial temperatures could thaw 30–85% of Arctic permafrost, risking major climate impacts. [6] [ clarification needed ] The IPCC Fourth Assessment Report (2007) projected that Arctic late-summer sea ice could largely disappear by the late 21st century, [6] [ needs update ] although significant retreat was already evident by 2007. [6] [ needs update ] In response, climate engineering has been proposed to slow or reverse these trends. [7]

Supporters of Arctic geoengineering argue it could stabilize permafrost carbon stores and limit further warming. [7] Arctic permafrost holds an estimated 1,700 billion metric tons of carbon—about 51 times the amount of annual global fossil fuel emissions. [8] Permafrost soils across the Northern Hemisphere contain about twice as much carbon as the atmosphere, and Arctic air temperatures have risen roughly six times faster than the global average. [7] Continued ice loss could substantially accelerate global warming. [7] Arctic sea ice also helps regulate global temperatures by limiting the release of strong greenhouse gases. [7]

Proposed geoengineering strategies aim to protect existing sea ice and encourage new ice growth. Methods include reducing sunlight reaching the surface, promoting freezing, and slowing melt rates. [7] [9] Approaches include stratospheric sulfate aerosol injection, pumping seawater onto ice to thicken it, and covering ice with hollow glass spheres to enhance reflectivity. [9] [8] These methods vary widely in cost, complexity, and technical feasibility. [9]

Solar radiation modifications (SRM) methods

This paragraph is an excerpt from Solar radiation modification.[ edit ]
Solar radiation modification (SRM) (or solar geoengineering or solar radiation management), is a group of large-scale approaches to reduce global warming by increasing the amount of sunlight (solar radiation) that is reflected away from Earth and back to space. Among the potential methods, stratospheric aerosol injection (SAI) is the most-studied, [10] : 350  followed by marine cloud brightening (MCB); others such as ground- and space-based methods show less potential or feasibility and receive less attention. SRM could be a supplement to climate change mitigation and adaptation measures, [11] : 1489  but would not be a substitute for reducing greenhouse gas emissions. [12] SRM is a form of climate engineering or geoengineering, and might be able to prevent some kinds of tipping. [13]

Stratospheric aerosol injection

SAI concentrated in polar regions is a proposed glacial geoengineering method to slow the melting of polar ice. It involves injecting small reflective particles, such as sulfur dioxide, high into the atmosphere over polar areas. These particles would reflect some sunlight back into space, leading to localized cooling and helping to preserve glaciers and sea ice. [14] Scientists have suggested that targeting aerosols at high latitudes could address polar amplification—the faster warming of the poles compared to the rest of the planet—more effectively than spreading aerosols evenly around the globe. [15] [16] Climate model studies show that polar-focused SAI could significantly reduce summer ice loss and slow sea-level rise. [17] [18] More recent research suggests that adjusting where and how aerosols are released—such as focusing injections between 60° and 70° latitude—could offer a better balance between cooling the poles and limiting disruptions to tropical weather systems like monsoons. [14] [19] However, even regional SAI could cause unintended side effects, such as weakening the polar vortex and altering global rainfall patterns. [15] [20]

Marine cloud brightening

MCB is a proposed glacial geoengineering method that would involve spraying fine seawater droplets into the atmosphere to make clouds more reflective, thereby cooling the surface below. In polar regions, MCB would aim to enhance cloud reflectivity over the oceans to reduce regional warming and slow ice loss. Research has suggested that targeting MCB at high latitudes could help stabilize Arctic sea ice without producing as many side effects as global interventions. [21] Observational studies of natural cloud brightening in the Southern Ocean have also shown that increasing cloud droplet concentration can significantly boost cloud reflectivity, supporting the potential effectiveness of polar-focused MCB. [22] The Centre for Climate Repair at Cambridge has proposed developing MCB techniques specifically to "refreeze" the Arctic by restoring the reflectivity of polar clouds (Centre for Climate Repair at Cambridge). [23]

Ocean albedo enhancement

Ocean albedo enhancement would aim to make open ocean surfaces near the poles more reflective, reducing the amount of solar energy absorbed by the water. One idea is to generate microbubbles or apply reflective foams across the ocean surface to increase its brightness. Studies suggest that even modest increases in surface reflectivity could contribute to localized cooling and help slow the loss of sea ice. [24] [25] Proposed techniques include releasing air bubbles from ships or using surface treatments to create a whiter ocean surface (https://climateinterventions.org/interventions/reflective-foams-and-bubbles-on-oceans/). [26] However, large-scale deployment of these methods remains theoretical. Challenges include maintaining a sufficient concentration of bubbles or foam over time, potential impacts on marine ecosystems, and the difficulty of covering large ocean areas in a sustainable way. [27]

Glass beads to increase albedo

Ice911, a non-profit organization whose goal is to reduce climate change, conducted an experiment in a lab. [28] They found that releasing reflective material on top of ice increased its albedo. [28] The reasoning behind this finding is that raising the ice's surfaces reflectivity increases its ability to reflect sunlight and therefore reduces the temperature on the ice's surface. [28] Of the materials used, Ice911 found glass was not only effective in raising the ice's albedo, but it was also financially feasible and environmentally friendly. [29] The team then moved forward and conducted field tests in California, Minnesota, and Alaska. [29] In all field testing locations, the albedo were increased in ice that had the glass beads poured on top of it compared to the ice that didn't have the glass beads added to its surface. [29] The findings indicate the glass beads placed on top of the ice increased the ice's reflectivity. [29]

Mechanical and engineering methods

Building thicker sea ice

It has been proposed to actively enhance the polar ice cap by spraying or pumping water onto the top of it which would build thicker sea ice. [30] [31] [32] A benefit of this method is that the increased salt content of the melting ice will tend to strengthen downwelling currents when the ice re-melts. [33] Some ice in the sea is frozen seawater. Other ice comes from glaciers, which come from compacted snow, and is thus fresh water ice.

A proposed method to build thicker sea ice is to use wind powered water pumps. These pumps contain a buoy that has a wind turbine attached to it, which functions to transfer the wind energy to power the pump. [34] The buoy also has a tank attached to it to store and release water as necessary. [34] In theory, pumping 1.3 meters of water on top of the ice, at the right time, could increase the ice's thickness by 1.0 meter. [34] The goal of this pump is to increase ice thickness in a way that is energy efficient. [34] Pumps powered by wind have been successfully used in the Antarctic to increase ice thickness. [34]

Decreasing water salinity

Decreased salinity of ocean water causes it to become less dense, which in turn causes changing ocean currents. [35] [36] For this reason, it has been suggested [37] that locally influencing salinity and temperature of the Arctic Ocean by changing the ratio of Pacific and fluvial waters entering through the Bering Strait could play a key role in preserving Arctic sea ice. The purpose would be to create a relative increase of fresh water inflow from the Yukon River, while blocking (part) of the warm and saltier waters from the Pacific Ocean. Proposed geoengineering options include a dam [38] connecting St. Lawrence Island and a threshold under the narrow part of the strait.

Limitations and risks

Adverse weather conditions

Because geoengineering is a relatively new concept, there are no real studies on the ramifications of these new technologies and how they may affect weather patterns, ecosystems, and the climate in the long term. [39] Certain methods of arctic geoengineering, such as injecting sulfate aerosol into the stratosphere to reflect more sunlight, or marine cloud brightening, may trigger a chain of events that may be irreversible. [40] For the case of sulfur injection, such effects may include ocean acidification or crop failure due to either delayed precipitation patterns, or by reducing the amount of sunlight needed for them to grow. [41] The latter effects are similar for marine cloud brightening. The process involves using boats to increase sea water aerosol particles in the clouds closest to Earth's surface in order to reflect sunlight. [40] [42]

Rapid Ozone Depletion

Nobel laureate Paul Crutzen proposed a method of geoengineering in which emitting sulfates into the lower atmosphere would lead to global cooling and theoretically help tackle climate change. [43] The possible downside of this is that injecting sulfates into the stratosphere has the potential to lead to ozone depletion. [43] The process by which this works is that sulfate particles come into contact with atmospheric chlorine and chemically alter them. This reaction is estimated to have the possibility to deplete between one-third and one-half of the ozone layer over the Arctic if it goes into effect. [43] A proposed alternative to prevent this from happening is to swap out sulfates for calcite particles, the idea being that this is the material emitted into the atmosphere during a volcanic eruption. [44] [45] [8] There have not been any prototypes of such an experiment thus far, and while this method would not reverse the damage already done to the environment, it may aid in reducing some of the long-term potential damage.

Effectiveness of reflective particles

There are concerns surrounding the effectiveness of using glass, and other reflective particles, to increase albedo. [3] A study conducted by Webster and Warren found these particles actually increase the melting rates of sea ice. [3] Webster and Warren argue that spreading glass over new ice works because the new ice is formed during the months with little sunlight; thus, the effectiveness of the glass beads cannot definitively be credited to the beads themselves. [3] Additionally, Webster and Warren argue the glass beads used in the study absorbed dark substances and overall decreased the albedo, which could potentially lead to a faster melting rate of sea ice.

See also


References

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  2. 1 2 Boé, Julien; Hall, Alex; Qu, Xin (15 March 2009). "September sea-ice cover in the Arctic Ocean projected to vanish by 2100". Nature Geoscience. 2 (5). Springer Nature: 341–343. Bibcode:2009NatGe...2..341B. doi:10.1038/ngeo467. ISSN   1752-0894.
  3. 1 2 3 4 Webster, Melinda A.; Warren, Stephen G. (27 March 2023). "Regional Geoengineering Using Tiny Glass Bubbles Would Accelerate the Loss of Arctic Sea Ice". Earth's Future. 10 (10). doi: 10.1029/2022EF002815 . ISSN   2328-4277. S2CID   252748547.
  4. 1 2 Fleming, James R. (2007). "The Climate Engineers" (PDF). The Wilson Quarterly. Retrieved 27 March 2023.
  5. ↑ Herrmann, Victoria (25 April 2016). "How Methane Affects the Arctic - Infographic".
  6. 1 2 3 4 "As the Arctic sea ice melts, be wary of 'Methane Emergency' claims". CarbonBrief. 14 August 2012.
  7. 1 2 3 4 5 6 Chen, Yating; Liu, Aobo; Moore, John C. (15 May 2020). "Mitigation of Arctic permafrost carbon loss through stratospheric aerosol geoengineering". Nature Communications. 11 (1): 2430. Bibcode:2020NatCo..11.2430C. doi:10.1038/s41467-020-16357-8. ISSN   2041-1723. PMC   7229154 . PMID   32415126.
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  9. 1 2 3 Bennett, Alec P.; Bouffard, Troy J.; Bhatt, Uma S. (25 May 2022). "Arctic Sea Ice Decline and Geoengineering Solutions: Cascading Security and Ethical Considerations". Challenges. 13 (1): 22. doi: 10.3390/challe13010022 . ISSN   2078-1547.
  10. ↑ Ipcc (9 June 2022). Global Warming of 1.5°C: IPCC Special Report on Impacts of Global Warming of 1.5°C above Pre-industrial Levels in Context of Strengthening Response to Climate Change, Sustainable Development, and Efforts to Eradicate Poverty (1 ed.). Cambridge University Press. doi:10.1017/9781009157940.006. ISBN   978-1-009-15794-0.
  11. ↑ Intergovernmental Panel on Climate Change (2021). Climate Change 2021: Mitigation of Climate Change – Working Group III Contribution.
  12. ↑ Helwegen, Koen G.; Wieners, Claudia E.; Frank, Jason E.; Dijkstra, Henk A. (15 July 2019). "Complementing CO2 emission reduction by solar radiation management might strongly enhance future welfare". Earth System Dynamics. 10 (3): 453–472. doi: 10.5194/esd-10-453-2019 . ISSN   2190-4979. even if successful, SRM can not replace but only complement CO2 abatement.
  13. ↑ Futerman, Gideon; Adhikari, Mira; Duffey, Alistair; Fan, Yuanchao; Irvine, Peter; Gurevitch, Jessica; Wieners, Claudia (10 October 2023). "The interaction of Solar Radiation Modification and Earth System Tipping Elements". EGUsphere: 1–70. doi: 10.5194/egusphere-2023-1753 .
  14. 1 2 Smith, Wake; Bhattarai, Umang; MacMartin, Douglas G; Lee, Walker Raymond; Visioni, Daniele; Kravitz, Ben; Rice, Christian V (1 September 2022). "A subpolar-focused stratospheric aerosol injection deployment scenario". Environmental Research Communications. 4 (9): 095009. Bibcode:2022ERCom...4i5009S. doi:10.1088/2515-7620/ac8cd3. ISSN   2515-7620.
  15. 1 2 Jackson, L. S.; Crook, J. A.; Jarvis, A.; Leedal, D.; Ridgwell, A.; Vaughan, N.; Forster, P. M. (28 February 2015). "Assessing the controllability of Arctic sea ice extent by sulfate aerosol geoengineering". Geophysical Research Letters. 42 (4): 1223–1231. Bibcode:2015GeoRL..42.1223J. doi:10.1002/2014GL062240. ISSN   0094-8276.
  16. ↑ Nalam, Aditya; Bala, Govindasamy; Modak, Angshuman (May 2018). "Effects of Arctic geoengineering on precipitation in the tropical monsoon regions". Climate Dynamics. 50 (9–10): 3375–3395. Bibcode:2018ClDy...50.3375N. doi:10.1007/s00382-017-3810-y. ISSN   0930-7575.
  17. ↑ Sun, Weiyi; Wang, Bin; Chen, Deliang; Gao, Chaochao; Lu, Guonian; Liu, Jian (October 2020). "Global monsoon response to tropical and Arctic stratospheric aerosol injection". Climate Dynamics. 55 (7–8): 2107–2121. Bibcode:2020ClDy...55.2107S. doi:10.1007/s00382-020-05371-7. ISSN   0930-7575.
  18. ↑ Tilmes, S.; Jahn, Alexandra; Kay, Jennifer E.; Holland, Marika; Lamarque, Jean-Francois (16 February 2014). "Can regional climate engineering save the summer Arctic sea ice?". Geophysical Research Letters. 41 (3): 880–885. Bibcode:2014GeoRL..41..880T. doi:10.1002/2013GL058731. ISSN   0094-8276.
  19. ↑ Bednarz, Ewa M.; Butler, Amy H.; Visioni, Daniele; Zhang, Yan; Kravitz, Ben; MacMartin, Douglas G. (3 November 2023). "Injection strategy – a driver of atmospheric circulation and ozone response to stratospheric aerosol geoengineering". Atmospheric Chemistry and Physics. 23 (21): 13665–13684. Bibcode:2023ACP....2313665B. doi: 10.5194/acp-23-13665-2023 . ISSN   1680-7324.
  20. ↑ Caldeira, Ken; Wood, Lowell (13 November 2008). "Global and Arctic climate engineering: numerical model studies". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences. 366 (1882): 4039–4056. Bibcode:2008RSPTA.366.4039C. doi:10.1098/rsta.2008.0132. ISSN   1364-503X.
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  22. ↑ Mace, Gerald G.; Benson, Sally; Humphries, Ruhi; Gombert, Peter M.; Sterner, Elizabeth (1 February 2023). "Natural marine cloud brightening in the Southern Ocean". Atmospheric Chemistry and Physics. 23 (2): 1677–1685. Bibcode:2023ACP....23.1677M. doi: 10.5194/acp-23-1677-2023 . ISSN   1680-7324.
  23. ↑ Centre for Climate Repair, University of Cambridge. "Refreeze the Arctic".
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  25. ↑ Webster, Melinda A.; Warren, Stephen G. (October 2022). "Regional Geoengineering Using Tiny Glass Bubbles Would Accelerate the Loss of Arctic Sea Ice". Earth's Future. 10 (10). doi:10.1029/2022EF002815. ISSN   2328-4277.
  26. ↑ UArctic. "Reflective foams and bubbles on oceans".
  27. ↑ Strawa, A.; Olinger, S.; Zornetzer, S.; Johnson, D.; Bhattacharyya, S.; Ivanova, D.; Field, L. (March 2025). "Application of Hollow Glass Microspheres in the Arctic Ocean Would Likely Lead to a Deceleration of Arctic Sea Ice Loss" ‐ A Critique of the Paper by Webster and Warren (2022)". Earth's Future. 13 (3). doi:10.1029/2024EF004749. ISSN   2328-4277.
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  34. 1 2 3 4 5 Desch, Steven J.; Smith, Nathan; Groppi, Christopher; Vargas, Perry; Jackson, Rebecca; Kalyaan, Anusha; Nguyen, Peter; Probst, Luke; Rubin, Mark E.; Singleton, Heather; Spacek, Alexander; Truitt, Amanda; Zaw, Pye Pye; Hartnett, Hilairy E. (19 December 2016). "Arctic ice management: ARCTIC ICE MANAGEMENT". Earth's Future. 5 (1): 107–127. doi: 10.1002/2016EF000410 . S2CID   133195273.
  35. ↑ Ray, C. Claiborne (25 August 2017). "Melting Icebergs Alter the Oceans". The New York Times .
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  37. ↑ Schuttenhelm, Rolf (13 September 2008). "Diomede Crossroads". Archived from the original on 25 July 2011.
  38. ↑ "Could a Massive Dam Between Alaska and Russia Save the Arctic?". HuffPost. 27 November 2010.
  39. ↑ Milman, Oliver (15 December 2022). "Can geoengineering fix the climate? Hundreds of scientists say not so fast". TheGuardian.com .
  40. 1 2 Harvey, Fiona (17 May 2022). "Climate geoengineering must be regulated, says former WTO head". TheGuardian.com .
  41. ↑ Kaufman, Rachel (11 March 2019). "The Risks, Rewards and Possible Ramifications of Geoengineering Earth's Climate".
  42. ↑ Latham, John; Bower, Keith; Choularton, Tom; Coe, Hugh; Connolly, Paul; Cooper, Gary; Craft, Tim; Foster, Jack; Gadian, Alan (13 September 2012). "Marine cloud brightening". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences. 370 (1974): 4217–4262. Bibcode:2012RSPTA.370.4217L. doi:10.1098/rsta.2012.0086. PMC   3405666 . PMID   22869798.
  43. 1 2 3 "Hazards of Geoengineering".
  44. ↑ Keith, David W.; Weisenstein, Debra K.; Dykema, John A. (12 December 2016). "Stratospheric solar geoengineering without ozone loss". Proceedings of the National Academy of Sciences. 113 (52): 14910–14914. Bibcode:2016PNAS..11314910K. doi: 10.1073/pnas.1615572113 . PMC   5206531 . PMID   27956628.
  45. ↑ Matthews, Dylan (30 November 2018). "Geoengineering is a last-ditch option to stall global warming — and it's getting a first test". Vox.
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