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Measuring Carbon-based Contaminant Mineralization Using Combined CO2 Flux and Radiocarbon Analyses
Published on: October 21, 2016
Las concentraciones de dióxido de carbono atmosférico antes de hace 2.200 millones de años
1Department of Earth and Planetary Sciences, Harvard University, Cambridge, Massachusetts 02138, USA.
Nature
|December 7, 1995
Resumen
Tierra temprana de la Tierra temprana.
Área de la Ciencia:
- Las geociencias son ciencias geológicas.
- Paleoclimatología Paleoclimatología
- Ciencias de la atmósfera Ciencias atmosféricas.
Sus antecedentes:
- La composición temprana de la atmósfera de la Tierra es objeto de debate.
- Es posible que se haya necesitado un mayor dióxido de carbono (CO2) para el calor debido a la menor luminosidad solar.
- Los paleosolos proporcionan restricciones en el oxígeno atmosférico temprano (pO2).
Objetivo del estudio:
- Restringir los niveles de dióxido de carbono atmosférico (pCO2) entre hace 2.75 y 2.2 mil millones de años.
- Investigar el papel del CO2 en la regulación del clima de la Tierra temprana.
- Reevaluar los modelos climáticos para el Arqueo tardío y el Proterozoico temprano. eras.
Principales métodos:
- Análisis de paleozoos bien estudiados (perfiles de desgaste fósil).
- Examinando los patrones de precipitación de hierro dentro de los perfiles de paleosol.
- Utilizando la formación de silicato de hierro y carbonato de hierro para inferir los niveles de pCO2.
Principales resultados:
- El pCO2 atmosférico fue inferior a 10−1,4 atm (aprox. 100 veces los niveles actuales).
- Este nivel es significativamente más bajo de lo predicho por los modelos climáticos para la Tierra temprana.
- La representación del hierro como silicatos, no como carbonatos, indica que el CO2 es limitado.
Conclusiones:
- La sensibilidad climática de la Tierra primitiva al CO2 puede ser más alta de lo que se suponía anteriormente.
- Otros gases de efecto invernadero probablemente jugaron un papel importante en la regulación del clima antiguo.
- Los hallazgos desafían los modelos existentes de composición atmosférica y clima del Arqueo y el Proterozoico.
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