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Eventos de calentamiento extremo en el pasado vinculados a la liberación masiva de carbono por el deshielo del

Robert M DeConto¹, Simone Galeotti, Mark Pagani

¹Department of Geosciences, University of Massachusetts, Amherst, Massachusetts 01002, USA. deconto@geo.umass.edu

|April 7, 2012

Resumen

Los antiguos hipertermales de la Tierra, incluido el Máximo Térmico Paleoceno-Eoceno (PETM), se desencadenaron por ciclos orbitales que causaron la liberación de carbono del permafrost. Esto explica el momento y la magnitud de estos eventos extremos de calentamiento global.

Área de la Ciencia:

Paleoclimatología Paleoclimatología
La geoquímica es la geoquímica.
Modelado del clima Modelado del clima

Sus antecedentes:

La Tierra experimentó eventos extremos de calentamiento global (hipertermales) entre hace 55.5 y 52 millones de años.
El Máximo Térmico Paleoceno-Eoceno (PETM) involucró una liberación masiva de carbono, acidificación de los océanos y un aumento de la temperatura de 5 ° C.
Los modelos existentes luchan por explicar la fuente de carbono, la magnitud y el momento de estos hipertermales.

Objetivo del estudio:

Para investigar los impulsores detrás de los hipertermales del Eoceno Temprano, incluido el PETM.
Desarrollar un modelo unificador para la liberación de carbono durante estos eventos de calentamiento.

Principales métodos:

Utilizó un nuevo registro ciclostratigráfico calibrado astronómicamente de Italia.
Realizó simulaciones de clima-ecosistema-suelo que incorporaron gases de efecto invernadero y forzamiento orbital.

Principales resultados:

Los hipertermales del Eoceno temprano coincidieron con configuraciones orbitales específicas de la Tierra (alta excentricidad y oblicuidad).
Las simulaciones indican que la descomposición de carbono orgánico del suelo del permafrost desencadenada en órbita explica el PETM y los hipertermales posteriores.
Miles de petagramas de carbono fueron liberados del permafrost, amplificado por un umbral de calentamiento pre-PETM.

Conclusiones:

Las propiedades orbitales de la Tierra son un factor clave para desencadenar la liberación masiva de carbono del permafrost.
El permafrost actuó como un reservorio sensible de carbono, influyendo en la magnitud y la frecuencia de los hipertermales.
La disminución de la extensión del permafrost con el aumento de las temperaturas de fondo condujo a hipertermales subsecuentes más pequeños.

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