古代の永久凍土と,より温暖な北極の未来です
Duane G Froese1, John A Westgate, Alberto V Reyes
1Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, AB T5M 0M3, Canada. duane.froese@ualberta.ca
まとめ
カナダの古代の永久凍土は,70万年以上前のもので,過去の温暖な時期を生き延びている. この発見は,地球温暖化による広範囲にわたる永久凍土の解凍を予測する気候モデルに挑戦しています.
科学分野:
- 地球科学 地球科学 地球科学
- 古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは
- 気候科学 気候科学
背景:
- 気候モデルでは,地球温暖化によって永久凍土が著しく劣化すると予測されており,蓄積された炭素を大量に放出する可能性がある.
- これらのモデルを評価することは,過去の温暖な気候における永久凍土の歴史的行動の理解が限られているため,困難です.
研究 の 目的:
- 永久凍土の長期的安定性と,過去の氷期間の温暖化イベントに対するその回復力を調査する.
- 温暖化への永久凍土の反応に関する気候モデルの予測を精錬するための経験的データを提供すること.
主な方法:
- 地質調査とカナダの亜北極圏の地下氷の堆積物の分析.
主要な成果:
- 年齢が70万年を超える地下氷の遺跡を発見.
- 証拠によると,この古代の地下氷は,過去の複数の間氷期を経て存続した.
結論:
- この地域の永久凍土は,現在の気候モデルによって予測されるよりも高い安定性を示しています.
- 過去のより暖かい氷河間期は,現在のより長く,この古代の地面氷の完全な融解を引き起こさなかった.
- この発見は,気候変動予測における永久凍土の炭素フィードバックメカニズムを再評価することを必要としています.
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