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10:28
Investigating the Relationship between Sea Surface Chlorophyll and Major Features of the South China Sea with Satellite Information
Published on: June 13, 2020
Evolution of the atmosphere and oceans
H D Holland1, B Lazar, M McCaffrey
1Department of Geological Sciences, Harvard University, Cambridge, Massachusetts 02138, USA.
Nature
|March 6, 1986
Summary
Earth
Area of Science:
- Geochemistry
- Atmospheric Science
- Paleoclimatology
Background:
- Atmospheric and oceanic constituents are in dynamic equilibrium.
- Current human activities are severely disrupting these natural balances.
- Past Earth conditions differed significantly from present ones.
Purpose of the Study:
- To investigate past atmospheric and oceanic chemistry.
- To understand the impact of the biosphere on atmospheric evolution.
- To assess the severity of current anthropogenic disturbances.
Main Methods:
- Analysis of marine evaporite mineralogy.
- Examination of ancient soil chemistry.
- Reconstruction of paleo-atmospheric composition.
Main Results:
- Sea water composition has been stable for at least 900 million years (Myr).
- Ancient atmospheres (over 1,000 Myr ago) had higher CO2 and lower O2.
- Hydrogen peroxide and formaldehyde were likely key redox agents in early rainwater.
Conclusions:
- The evolution of the biosphere is strongly linked to major atmospheric chemistry changes since 1,000 Myr ago.
- Current disturbances to Earth's dynamic equilibria are unprecedented.
- Understanding past changes is crucial for assessing future climate and atmospheric alterations.
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