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The early atmosphere was mainly carbon dioxide and water vapour. Water vapour condensed to form the oceans. Photosynthesis caused the amount of carbon dioxide to decrease and oxygen to...
- Polluting The Atmosphere
Electromagnetic radiation at most wavelengths passes through...
- Sample Exam Questions
Get ready for your exams with this BBC Bitesize GCSE...
- Polluting The Atmosphere
19 Αυγ 2009 · But roughly 2.45 billion years ago, the isotopic ratio of sulfur transformed, indicating that for the first time oxygen was becoming a significant component of Earth's atmosphere, according...
19 Φεβ 2014 · Nature - Until about two billion years ago free oxygen was a scarce commodity in the Earth's atmosphere. For decades geochemists have been refining the story of how and when early life...
2 ημέρες πριν · For decades, scientists believed that the atmosphere of early Earth was highly reduced, meaning that oxygen was greatly limited. Such oxygen-poor conditions would have resulted in an atmosphere filled with noxious methane, carbon monoxide, hydrogen sulfide, and ammonia.
13 Μαΐ 2016 · An MIT study finds oxygen first entered the Earth’s atmosphere 2.33 billion years ago, rising rapidly over 10 million years, and eventually spurring the evolution of complex life.
7 Αυγ 2018 · The evidence comes from a new study that indicates a second and much earlier “whiff” of oxygen in Earth’s distant past — in the atmosphere and on the surface of a large stretch of ocean — showing that the oxygenation of the Earth was a complex process of repeated trying and failing over a vast stretch of time.
6 Οκτ 2021 · A new study seeks to settle a debate about the amount of molecular oxygen in Earth’s early atmosphere. Researchers supported by the NASA Astrobiology Program have been studying an event in Earth’s history known as the ‘Great Oxidation Event,’ when a rise in atmospheric oxygen altered the environment and the biosphere of our planet some ...
