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Los lagos de termokarst como fuente de CH4 atmosférico durante la última deglaciación
K M Walter1, M E Edwards, G Grosse
1Water and Environmental Research Center, University of Alaska, Fairbanks, AK 99775, USA. ftkmw1@uaf.edu
Science (New York, N.Y.)
|October 27, 2007
Resumen
El metano (CH4) liberado por el deshielo de los lagos árticos durante el calentamiento climático contribuyó significativamente al aumento de los niveles globales de CH4. Este estudio cuantifica el impacto sustancial de las emisiones de CH4 del lago termokarst en el cambio climático pasado.
Área de la Ciencia:
- Paleoclimatología Paleoclimatología
- La geoquímica es la geoquímica.
- Ciencias del medio ambiente Ciencias del medio ambiente.
Sus antecedentes:
- Los registros de núcleos de hielo indican un aumento significativo en el metano atmosférico (CH4) durante los últimos períodos de calentamiento deglacial.
- Se sospecha que una fuente ártica o boreal representa más del 30% de este aumento de metano, pero las fuentes específicas siguen siendo objeto de debate.
Objetivo del estudio:
- Para estimar el flujo de metano de los lagos de termokarst (deshielo) durante la deglaciación pasada.
- Determinar la contribución de las emisiones de CH4 del lago termokarst al aumento general del metano atmosférico durante la transición Pleistoceno-Holoceno.
Principales métodos:
- Se utilizaron datos sobre el lago de termokarst ártico contemporáneo, tasas de burbujas de CH4.
- Potenciales de producción de CH4 incorporados de materia orgánica antigua a partir de sedimentos congelados.
- Estimó la extensión histórica del desarrollo del lago termokarst durante la deglaciación.
Principales resultados:
- Se estima que el burbujeo de CH4 de los lagos de termokarst recién formados ha contribuido del 33% al 87% del aumento de la latitud alta en el metano atmosférico.
- Estas emisiones jugaron un papel en la amplificación del calentamiento climático en la transición Pleistoceno-Holoceno.
Conclusiones:
- Las emisiones de CH4 del lago termokarst fueron un factor importante del aumento de metano atmosférico durante la deglaciación pasada.
- Comprender estas antiguas fuentes de metano es crucial para predecir las retroalimentaciones climáticas futuras de las regiones de deshielo del permafrost.
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