The poles are warming several times faster than the global average, causing record heat waves that were reported earlier this year in both the Arctic and Antarctica. Melting ice and the collapse of glaciers at high latitudes would accelerate sea level rise around the planet. Fortunately, refreezing the poles by reducing sunlight would be both feasible and remarkably cheap, according to new research published today in Environmental Research Communications.
Scientists have outlined a possible future program in which high-flying aircraft would spray microscopic aerosol particles into the atmosphere at latitudes of 60 degrees north and south – roughly Anchorage and the southern tip of Patagonia. If injected at an altitude of 43,000 feet (above airliner cruise altitudes), these aerosols would slowly drift poleward, slightly shading the surface below. “There is widespread and sensitive concern about deploying aerosols to cool the planet,” notes lead author Wake Smith, “but if the risk/benefit equation paid off anywhere, it would be at the poles.”
Particle injections would be performed seasonally during the long days of the local spring and early summer. The same fleet of aircraft could serve both hemispheres, flying to the opposite pole as the seasons change.
Pre-existing military air-to-air refueling tankers, such as the aging KC-135 and A330 MMRT, do not have sufficient payload at the required altitudes, while newly designed high-altitude tankers would prove much more efficient. A fleet of about 125 such tanks could lift enough payload to cool the regions poleward of 60°N/S by 2°C per year, which would bring them close to their pre-industrial average temperatures. The costs are estimated at $11 billion annually – less than a third of the cost of cooling the entire planet by the same magnitude of 2°C and a fraction of the cost of achieving net zero emissions.
“In a rapidly warming world, stratospheric aerosol injections only treat a symptom of climate change, not the underlying disease. It’s aspirin, not penicillin. It’s not a substitute for decarbonisation,” says Smith.
Cooling at the poles would provide direct protection for only a small part of the planet, although mid-latitudes should also experience some reduction in temperature. Since less than 1% of the global human population lives in the target deployment areas, a polar deployment would involve far fewer direct risks to most of humanity than a global program. “However, any intentional turning of the global thermostat would be in the common interest of all humanity and not just the province of the Arctic and Patagonian nations,” adds Smith.
In summary, the current study is only a small and preliminary step toward understanding the costs, benefits, and risks of the high-latitude climate intervention enterprise. It provides further reason to believe that such tools could prove useful both for preserving the cryosphere near the poles and for slowing global sea-level rise.
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Wake Smith et al., A Deployment Scenario of Subpolar Focused Stratospheric Aerosol Injection, Environmental Research Communications (2022). DOI: 10.1088/2515-7620/ac8cd3
Provided by the Institute of Physics
Citation: Refreezing Earth’s Poles Feasible and Cheap, New Study Finds (2022, September 16) Retrieved September 20, 2022, from https://phys.org/news/2022-09-refreezing-earth-poles-feasible-cheap.html
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