Žemės ašigaliai šyla kelis kartus greičiau nei pasaulio vidurkis. Tiesą sakant, anksčiau šiais metais buvo pranešta apie rekordines karščio bangas tiek Arktyje, tiek Antarktidoje. Ledo tirpimas ir ledynų griūtis didelėse platumose paspartintų jūros lygio kilimą aplink planetą. Laimei, būtų nepaprastai įmanoma ir pigu pakartotinai užšaldyti stulpus sumažinant patenkančią saulės šviesą. Tai pagal naują tyrimą, paskelbtą 2022 m. rugsėjo 15 d. IOP Publishing. Aplinkos tyrimų komunikacijos.

Mokslininkai sukūrė potencialią būsimą geoinžinerijos programą, pagal kurią didelio aukščio purkštukai purškia mikroskopines aerozolio daleles į atmosferą 60 laipsnių šiaurės ir pietų platumose – maždaug Ankorige ir pietiniame Patagonijos gale. Įpurškus 43 000 pėdų / 13 000 metrų aukštyje (virš orlaivio plaukiojimo aukščio), šie aerozoliai lėtai nuslinks link ašigalio, užtemdydami paviršių šiek tiek žemiau.

Pagrindinis autorius Wake’as Smithas pažymi: „Yra plačiai paplitęs ir pagrįstas susirūpinimas dėl aerozolių panaudojimo planetai vėsinti, bet jei rizikos ir naudos lygtis pasiteisins bet kur, tai yra ašigaliai“. Smithas dėstytojas[{” 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