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Cambios en la productividad primaria de la biosfera global durante los últimos ocho ciclos glaciales
Ji-Woong Yang1, Margaux Brandon1,2, Amaëlle Landais1
1Laboratoire des Sciences du Climat et de l'Environnement/Institut Pierre-Simon Laplace, Université Paris Saclay/CEA/CNRS/UVSQ, Gif-sur-Yvette, France.
Science (New York, N.Y.)
|March 10, 2022
Resumen
La productividad global de la biosfera, la mayor absorción de dióxido de carbono (CO2), fue menor durante los períodos glaciales pasados. El aumento de los niveles de CO2 parece impulsar esta productividad, lo que sugiere un ciclo de retroalimentación climática.
Área de la Ciencia:
- Paleoclimatología
- Biogeoquímica
- Ciencias del Sistema Terrestre
Sus antecedentes:
- La productividad global de la biosfera es un factor clave en el ciclo del dióxido de carbono (CO2) atmosférico.
- La estimación precisa de la productividad global de la biosfera en el pasado es crucial para comprender la dinámica del ciclo del carbono.
- Los métodos actuales para estimar la productividad histórica de la biosfera tienen limitaciones.
Objetivo del estudio:
- Para reconstruir un registro de 800.000 años de la productividad de la biosfera global.
- Investigar la relación entre la productividad de la biosfera en el pasado y los niveles de CO2 atmosférico.
- Comprender el papel de la productividad de la biosfera en los ciclos climáticos glaciales e interglaciales.
Principales métodos:
- Análisis de las relaciones isotópicas triples de oxígeno atmosférico atrapado en núcleos de hielo polar.
- Reconstrucción de la composición atmosférica pasada más de 800.000 años.
- Correlación de los indicadores de productividad de la biosfera con los datos sobre CO2 y el clima.
Principales resultados:
- El estudio presenta el primer registro de 800.000 años de productividad de la biosfera global derivado de los isótopos de oxígeno del núcleo de hielo.
- La productividad de la biosfera global pasada durante ocho intervalos glaciales fue menor que los niveles preindustriales.
- Los aumentos de la productividad de la biosfera a menudo precedieron a las deglaciaciones por milenios y coincidieron con los cambios de CO2.
Conclusiones:
- El CO2 atmosférico es el principal motor de la productividad de la biosfera global.
- La productividad de la biosfera exhibe un mecanismo de retroalimentación negativa bajo condiciones climáticas glaciales.
- Comprender las variaciones de productividad del pasado mejora las predicciones de las respuestas futuras del ciclo del carbono al cambio climático.
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