科学者は、地球の極を再凍結することは可能であり、非常に安価であると言います

新しい研究によると、入射する太陽光を減らして極を再凍結することは可能であり、非常に安価です。

地球の両極は、世界平均の数倍の速さで温暖化しています。 実際、今年初めに北極と南極の両方で記録的な熱波が報告されました。 高緯度での氷の融解と氷河の崩壊は、地球周辺の海面上昇を加速させるでしょう。 幸いなことに、入射する太陽光を減らして極を再凍結することは、非常に実現可能で安価です。 これは、2022 年 9 月 15 日に IOP Publishing で公開された新しい研究によると、 環境研究コミュニケーション.

科学者たちは、北緯 60 度、南北緯 60 度、おおよそアンカレッジとパタゴニアの南端で、高高度ジェットが微視的なエアロゾル粒子を大気に吹き込む、将来の可能性のあるジオエンジニアリング プログラムを考案しました。 43,000 フィート/13,000 メートル (航空機の航行高度より上) で噴射された場合、これらのエアロゾルは極に向かってゆっくりとドリフトし、表面のわずかに下を覆います。

筆頭著者のウェイク・スミスは次のように述べています。 スミス講師[{” 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