Los científicos dicen que volver a congelar los polos de la Tierra es factible y sorprendentemente barato

Enfriar los polos reduciendo la luz solar entrante sería factible y significativamente más barato, según una nueva investigación.

Los polos de la Tierra se están calentando varias veces más rápido que el promedio mundial. De hecho, a principios de este año, se registraron temperaturas récord tanto en el Ártico como en la Antártida. El derretimiento del hielo y el colapso de los glaciares en latitudes altas acelerarán el aumento del nivel del mar en el planeta. Afortunadamente, sería factible y significativamente más barato volver a congelar los polos reduciendo la luz solar entrante. Esto es según una nueva investigación publicada el 15 de septiembre de 2022 en IOP Publishing. Comunicación de Investigación Ambiental.

Los científicos han desarrollado un futuro proyecto de geoingeniería en el que aviones de alto vuelo rociarían partículas de aerosol microscópicas en la atmósfera en latitudes entre 60 grados norte y sur, aproximadamente en Anchorage y el extremo sur de la Patagonia. Si se inyecta a una altitud de 43 000 pies / 13 000 metros (por encima de la altitud de crucero de la línea aérea), estos aerosoles se desplazarán lentamente hacia el polo, sombreando ligeramente la superficie.

«Existe una preocupación generalizada y razonable sobre el despliegue de aerosoles para enfriar el planeta», señala el autor principal, Wake Smith, «pero si la ecuación riesgo/beneficio va a dar sus frutos en algún lugar, será en los polos». Smith es un profesor[{» attribute=»»>Yale University and a Senior Fellow at the Mossavar-Rahmani Center for Business and Government at Harvard Kennedy School.

Particle injections would be performed seasonally in the long days of the local spring and early summer. Both hemispheres could be serviced by the same fleet of jets, ferrying to the opposite pole with the change of seasons.

A tabular iceberg floating within Paradise Harbour, Antarctica. Credit: IOP Publishing

Pre-existing military air-to-air refueling tankers such as the aged KC-135 and the A330 MMRT don’t have enough payload at the required altitudes. However, newly designed high-altitude tankers would prove much more efficient. A fleet of roughly 125 such tankers could loft a payload sufficient to cool the regions poleward of 60°N/S by 2°C per year. This would be enough to return them close to their pre-industrial average temperatures. Annual costs are estimated at $11 billion. This is less than one-third the cost of cooling the entire planet by the same 2°C magnitude and just a tiny fraction of the cost of reaching net zero emissions.

“Game-changing though this could be in a rapidly warming world, stratospheric aerosol injections merely treat a symptom of climate change but not the underlying disease. It’s aspirin, not penicillin. It’s not a substitute for decarbonization,” says Smith.

Cooling at the poles would provide direct protection for only a small portion of the planet. However, the mid-latitudes should also experience some temperature reduction. Since less than 1% of the global human population lives in the target deployment zones, a polar deployment would entail much less direct risk to most of humanity than a global program.

“Nonetheless, any intentional turning of the global thermostat would be of common interest to all of humanity and not merely the province of Arctic and Patagonian nations,” adds Smith.

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

Reference: “A subpolar-focused stratospheric aerosol injection deployment scenario” by Wake Smith, Umang Bhattarai, Douglas G MacMartin, Walker Raymond Lee, Daniele Visioni, Ben Kravitz and Christian V Rice, 15 September 2022, Environmental Research Communications.
DOI: 10.1088/2515-7620/ac8cd3