今日の強いエアロゾール冷却は,暑い未来を暗示しています.
Meinrat O Andreae1, Chris D Jones, Peter M Cox
1Max Planck Institute for Chemistry, PO Box 3060, Mainz 55131, Germany. andreae@mpch-mainz.mpg.de
Nature
|July 1, 2005
まとめ
大気中のエアロゾールは地球を冷却しますが,将来の地球温暖化への影響は不明です. エアロゾール冷却の減少は,温暖化が現在の予測を超えて加速する可能性を示唆しています.
科学分野:
- 気候科学 気候科学
- 大気化学 大気化学
- 地球システム科学 地球システム科学
背景:
- 人為的な温室効果ガスは地球温暖化を引き起こしている.
- 大気中のエアロゾールは冷却効果を発揮し,ある程度の温暖化に対抗する.
- エアロゾール効果の不確実性は,気候変動予測に重大な課題をもたらします.
研究 の 目的:
- 気候変動における大気中のエアロゾールの役割を調査する.
- 減少するエアロゾール冷却が将来の温暖化に与える影響を評価する.
- 気候感受性推定と炭素サイクルフィードバック予測を精査する.
主な方法:
- 気候モデルの出力の分析.
- エアロゾールと温室効果ガスに関する観測データのレビュー.
- エアロゾールと温室効果ガスの相互作用の評価.
主要な成果:
- エアロゾールによる冷却はかなりありますが,非常に不確実です.
- 将来のエアロゾール冷却は,よりクリーンな大気政策により減少すると予測されています.
- この減少は,将来の温暖化がIPCCの予測のより高い端にある可能性を示唆しています.
結論:
- エアロゾールの気候感受性に対する純効果は,依然として重要な不確実性です.
- エアロゾルの強制力の減少は,温室効果ガスの温暖化を増幅します.
- 将来の地球温暖化は,緩和措置を講じずに現在の上限予測を上回る可能性があります.
関連する概念動画
01:16What is Climate?
Climate refers to the prevailing weather conditions in a specific area over an extended period. As the saying goes, “Climate is what you expect. Weather is what you get.” Climate is influenced by geographic factors, such as latitude, terrain, and proximity to bodies of water.
01:50Global Climate Change
Throughout its ~4.5 billion year history, the Earth has experienced periods of warming and cooling. However, the current drastic increase in global temperatures is well outside of the Earth’s cyclic norms, and evidence for human-caused global climate change is compelling. Paleoclimatology, the study of ancient climate conditions, provides ample evidence for human-caused global climate change by comparing recent conditions with those in the past.
02:39Phase Transitions: Vaporization and Condensation
The physical form of a substance changes on changing its temperature. For example, raising the temperature of a liquid causes the liquid to vaporize (convert into vapor). The process is called vaporization—a surface phenomenon. Vaporization occurs when the thermal motion of the molecules overcome the intermolecular forces, and the molecules (at the surface) escape into the gaseous state. When a liquid vaporizes in a closed container, gas molecules cannot escape. As these gas phase molecules...
01:12Precipitation Processes
The experimental conditions in a gravimetric analysis should be optimized to maximize the particle size and purity of the obtained precipitate. Ideally, the concentration of the precipitating reagent should be low with effective stirring to maintain low relative supersaturation for the growth of large crystals. In homogeneous precipitation, the precipitant is slowly generated by a chemical reaction in the solution to avoid local reagent excesses. For example, urea decomposes gradually to...
01:20Hot Weather Concreting
Concreting at elevated temperatures accelerates the hydration process, leading to quicker setting but potentially reducing the long-term strength of the concrete structure. Additionally, low air humidity fosters rapid moisture loss from the concrete, resulting in reduced workability, pronounced plastic shrinkage, and a higher likelihood of crazing.
Mitigating the heat increase in concrete can be economically achieved by shading aggregate stockpiles to prevent heating from solar radiation,...
Mitigating the heat increase in concrete can be economically achieved by shading aggregate stockpiles to prevent heating from solar radiation,...
01:27Microbes and Climate Change
Microorganisms are pivotal agents in Earth's biogeochemical cycles, significantly influencing climate dynamics through their metabolic activities. These microbes modulate the levels of key greenhouse gases by both contributing to and helping mitigate climate change.Microbial Contributions to Greenhouse Gas EmissionsRising global temperatures accelerate microbial metabolism, which, in turn, speeds up the decomposition of organic matter. This process releases carbon dioxide (CO₂) through...