Refreezing Earth’s poles is doable and cheap, new study finds

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The poles are warming several times faster than the global average, causing record-breaking heat waves that were reported earlier this year in the Arctic and Antarctica. Melting ice and collapsing glaciers at high latitudes would accelerate sea level rise around the planet. Fortunately, according to a new study published today in Communication of environmental research.

The scientists presented a possible future program in which high-altitude jets 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 from a height of 43,000 feet (above airliner cruising altitudes), these aerosols would slowly drift poleward, slightly shading the surface below. “There is widespread and reasonable apprehension about the deployment of aerosols to cool the planet,” notes lead author Wake Smith, “but if the risk/benefit equation were to hold up anywhere, it would be at the poles”.

Particle injections would be done seasonally during the long days of local spring and early summer. The same fleet of jets could service both hemispheres, ferrying to the opposite pole as the seasons change.

Pre-existing military air-to-air tankers such as the aging KC-135 and A330 MMRT do not have enough payload at the required altitudes, while newly designed high-altitude tankers would prove much more effective. A fleet of about 125 such tankers could carry enough payload to cool the regions towards the 60°N/S poles by 2°C per year, bringing them back close to their average pre-industrial temperatures. The costs are estimated at $11 billion a year, less than a third of the cost of cooling the entire planet by the same magnitude of 2°C and a tiny fraction of the cost to achieve net zero emissions.

“While it might be a game-changer in a rapidly warming world, stratospheric aerosol injections just treat a symptom of climate change, not the underlying disease. It’s aspirin, not penicillin. It’s not a substitute for decarbonization,” Smith says.

Cooling at the poles would only provide direct protection for a small fraction of the planet, although mid-latitudes are also expected to experience some reduction in temperature. Given that less than 1% of the world’s human population lives in the targeted deployment areas, a polar deployment would pose far less direct risk to the bulk of humanity than a global program. “Nevertheless, any intentional rotation of the global thermostat would be of common interest to all of humanity and not just the province of Arctic and Patagonian nations,” Smith adds.

In summary, the current study is only a small preliminary step towards understanding the costs, benefits and risks of undertaking climate intervention at high latitudes. This gives further reason to believe that such tools could prove useful both in preserving the cryosphere near the poles and in slowing global sea level rise.

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More information:
Wake Smith et al, A Subpolar Concentration Stratospheric Aerosol Injection Deployment Scenario, Communication of environmental research (2022). DOI: 10.1088/2515-7620/ac8cd3

Provided by the Institute of Physics

Quote: Refreezing Earth’s Poles Feasible and Cheap, Says New Study (2022, September 16) Retrieved September 16, 2022, from cheap.html

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