関連する実験動画
Updated: Dec 28, 2025

07:26
Visualizing Methane-Cycling Microbial Dynamics in Coastal Wetlands
Published on: January 31, 2025
736
古い炭素貯蔵庫は,脱氷期のメタン予算では重要ではなかった
M N Dyonisius1, V V Petrenko2, A M Smith3
1Department of Earth and Environmental Sciences, University of Rochester, Rochester, NY 14627, USA. mdyonisi@ur.rochester.edu.
まとめ
古代の炭素源からのメタンの排出は 過去の温暖化イベントでは最小でした これは将来の温暖化が 永久凍土や水素からメタンの大量放出を引き起こさないことを示唆しています
科学分野:
- 気候科学
- 古代気候学
- 地化学
背景:
- 永久凍土とメタンの水分は 膨大な量の古い炭素を貯蔵します
- 地球が温暖化すると 強力な温室効果ガスであるメタンが放出される危険性があります
- 過去の脱氷は 気候によるメタンの放出に 洞察力を与えてくれます
研究 の 目的:
- 最後の脱氷期における古い炭素貯蔵庫からのメタンの排出量を定量化するためです.
- 永久凍土と水素からメタンが大量に放出される可能性を評価する.
- バイオマス燃焼による工業化以前のメタンの排出量を推定する.
主な方法:
- メタン (Δ14C, δ13C, δD) の同位体測定を用いた氷核分析.
- 最後の脱氷期におけるメタン源と排出量の再構成
- 脱氷期からの排出量と工業化以前のおよび現代のメタン排出量との比較
主要な成果:
- 脱氷期における古い炭素貯蔵庫からのメタン排出量は小さい (<19 Tg/年).
- 工業化以前のホロセーン期にはバイオマスの燃焼によってメタンの排出量は22~56Tg/年に達し,現在の水準に相当する.
- 過去の温暖化で永久凍土と水素からメタンの放出が限られていることが示唆されています.
結論:
- 過去の温暖化は古い炭素貯蔵庫からメタンの大量排出を誘導しなかった.
- 永久凍土や水素からの将来のメタン排出量は 懸念されるほど高くないでしょう
- バイオマスの燃焼は工業化以前のホロセンの重要なメタン源でした.
関連する概念動画
Global Climate Change
28.4K
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.
28.4K
Overview of Archaea
652
Archaea, named after the Archaean eon, represent a unique domain of life, distinct from bacteria and eukaryotes, with remarkable traits. Their cellular and molecular features, ecological adaptability, and industrial relevance highlight their importance in understanding life processes and leveraging biotechnology.Cellular and Molecular CharacteristicsA defining feature of archaea is their unique membrane composition. Archaeal membranes contain ether-linked isoprenoid lipids, which confer...
652
The Carbon Cycle
43.0K
Carbon is the basis of all organic matter on Earth, and is recycled through the ecosystem in two primary processes: one in which carbon is exchanged among living organisms, and one in which carbon is cycled over long periods of time through fossilized organic remains, weathering of rocks, and volcanic activity. Human activities, including increased agricultural practices and the burning of fossil fuels, has greatly affected the balance of the natural carbon cycle.
43.0K
Metabolism of Chemolithotrophs
649
Chemolithotrophs are microorganisms that obtain energy by oxidizing inorganic molecules such as hydrogen gas (H₂), ammonia (NH₃), reduced sulfur compounds (H₂S, S²⁻), and ferrous iron (Fe²⁺). Unlike heterotrophic organisms that rely on organic carbon, chemolithotrophs transfer electrons from these inorganic donors to the electron transport chain (ETC), generating a proton motive force (PMF) that drives ATP synthesis through oxidative phosphorylation.
649
The Fossil Record
26.9K
The fossil record documents only a small fraction of all organisms that have ever inhabited Earth. Fossilization is a rare process, and most organisms never become fossils. Moreover, the fossil record only exhibits fossils that have been discovered. Nevertheless, sedimentary rock fossils of long-lived, abundant, hard-bodied organisms dominate the fossil record. These fossils offer valuable information, such as an organism's physical form, behavior, and age. Studying the fossil record helps...
26.9K
Carbon-dioxide Fixation
521
Carbon dioxide fixation in prokaryotes enables the assimilation of inorganic carbon into organic molecules, supporting biosynthetic pathways, sustaining ecosystems, and contributing to the global carbon cycle. It also has industrial applications in carbon capture and bioproduct synthesis. Autotrophic organisms rely on this process to utilize CO₂ as a carbon source in diverse environments.The Calvin CycleThe Calvin cycle is the most widespread carbon fixation mechanism, primarily used by...
521

