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Carbono-14 en las fuentes de metano y en el metano atmosférico: la contribución del carbono fósil
Resumen
El metano de los rumiantes contiene carbono contemporáneo, mientras que otras fuentes biogénicas están agotadas en carbono-14. Los combustibles fósiles representaron el 21% del metano atmosférico en 1987, y los reactores nucleares surgieron como una fuente.
Área de la Ciencia:
- Ciencias ambientales Ciencias ambientales.
- La radioquímica es la radioquímica.
- Química de la atmósfera La química de la atmósfera
Sus antecedentes:
- El metano (CH4) es un potente gas de efecto invernadero con diversas fuentes.
- La datación por carbono-14 (14C) es crucial para distinguir el biogénico del metano fósil.
- Comprender la composición isotópica del metano es clave para la investigación del cambio climático.
Objetivo del estudio:
- Para diferenciar las fuentes de metano utilizando mediciones de carbono-14.
- Para cuantificar la contribución del carbono fósil al metano atmosférico.
- Evaluar el papel de la energía nuclear en las emisiones de metano.
Principales métodos:
- Análisis radiométrico del carbono-14 en muestras de metano de diversas fuentes.
- Medición de las concentraciones de metano y de los isótopos del delta 13C en muestras atmosféricas.
- Modelado de transporte atmosférico para dividir las fuentes de metano.
Principales resultados:
- El metano de los rumiantes contiene carbono contemporáneo; los humedales, el pantano, el arroz y el metano de la tundra están agotados en 14C.
- El 14CH4 atmosférico aumentó desde 1986-1987, alcanzando 123.3 pMC (Norte) y 120.0 pMC (Sur) a finales de 1987.
- El carbono fósil comprendía 21% +/- 3% de metano atmosférico; los reactores de agua a presión son una fuente creciente de 14CH4.
Conclusiones:
- El análisis de carbono-14 distingue efectivamente las fuentes de metano.
- Las emisiones de combustibles fósiles contribuyen significativamente al metano atmosférico.
- Los reactores de agua presurizada representan una fuente antropogénica emergente de metano.
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