과학자들은 지구의 극을 재동결하는 것이 가능하고 매우 저렴하다고 말합니다.

지구의 극은 지구 평균보다 몇 배 더 빠르게 온난화되고 있습니다. 실제로 올해 초 북극과 남극에서 기록적인 폭염이 보고되었습니다. 고위도에서 녹는 얼음과 붕괴하는 빙하는 지구 주변의 해수면 상승을 가속화할 것입니다. 다행히도 들어오는 햇빛을 줄여 극지방을 다시 얼리는 것은 매우 실현 가능하고 저렴할 것입니다. 이는 IOP Publishing의 2022년 9월 15일에 발표된 새로운 연구에 따른 것입니다. 환경 연구 커뮤니케이션.

과학자들은 고도의 제트기가 남북 60도 위도(대략 앵커리지와 파타고니아 남단)의 대기 중으로 미세한 에어로졸 입자를 분사하는 잠재적인 미래 지구 공학 프로그램을 고안했습니다. 43,000피트/13,000미터(항공기 순항 고도 이상)에서 분사되는 경우 이러한 에어로졸은 극쪽으로 천천히 이동하여 약간 아래 표면에 음영을 줍니다.

수석 저자인 Wake Smith는 “지구를 식히기 위해 에어로졸을 배치하는 것에 대해 광범위하고 합리적인 두려움이 있지만 위험/이득 방정식이 어느 곳에서나 성과를 거두려면 극과 극에 있습니다.”라고 말합니다. 스미스 강사[{” 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