陸上の生態系による炭素交換の最近のパターンとメカニズム
D S Schimel1, J I House, K A Hibbard
1Max Planck Institute für Biogeochemie, Jena, Germany. schmiel@ucar.edu
Nature
|November 9, 2001
まとめ
陸上の生態系は,大気中の二酸化炭素を吸収して,1990年代に重要な炭素吸収器となった. 主に北部の地域におけるこのシフトは,気候変動を制限するのに役立つが,長期的な安定性とプロセスに不確実性を伴う.
科学分野:
- 地球システム科学 地球システム科学
- エコロジー エコロジー エコロジー
- 気候科学 気候科学
背景:
- 陸上と海洋の生態系は,人類による二酸化炭素排出量の約50%を吸収する.
- 炭素の交換を理解することは,大気と気候の変化を予測するために非常に重要です.
- この炭素吸収の長期的な安定性は依然として不確実である.
研究 の 目的:
- 地球上の生態系における地球的および地域的な炭素交換パターンの概要を提示する.
- 1980年代から1990年代までの地上の炭素吸収源の進化を分析する.
- 地上の炭素交換の変化に寄与する要因を特定する.
主な方法:
- 大気中の二酸化炭素と酸素データの分析.
- グローバルなおよび地域的な炭素交換パターンの評価.
- 土地利用の変化と炭素循環に影響を与える環境要因のレビュー.
主要な成果:
- 陸上の生物圏は1980年代にほぼ中性的な炭素交換から1990年代に純炭素吸収へと移行した.
- 北部の熱帯圏外地域,特に北米とユーラシアは,この最近の沈没に大きく貢献しました.
- 熱帯の陸地では,ほぼ中性的な炭素交換が示され,森林伐採による排出量のバランスをとった.
結論:
- 地球上の生態系は,大気中の二酸化炭素を吸収することによって,気候変動の緩和に重要な役割を果たしています.
- 土地利用の変化や,成長期の延長や二酸化炭素の肥料化などの環境要因が,地球上の炭素吸収源を牽引している.
- 地域間の沈殿地の規模と,さまざまなプロセスの具体的な貢献について,依然として大きな不確実性が残っています.
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