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Emisión de bromuro de metilo por la quema de biomasa
Science (New York, N.Y.)
|March 4, 1994
Resumen
La quema de biomasa es una fuente significativa de bromuro de metilo, un compuesto que agota el ozono estratosférico. Este hallazgo añade una importante vía para comprender el presupuesto global de bromo.
Área de la Ciencia:
- Química de la atmósfera La química de la atmósfera
- Ciencias ambientales Ciencias ambientales.
- Investigación de la capa de ozono Investigación de la capa de ozono.
Sus antecedentes:
- El bromuro de metilo es la principal fuente de bromo estratosférico, crucial para el agotamiento del ozono.
- Las fuentes conocidas incluyen las emisiones oceánicas y el uso de pesticidas agrícolas.
- Los átomos de bromo son significativamente más efectivos que los átomos de cloro para destruir el ozono.
Objetivo del estudio:
- Investigar la combustión de la biomasa como fuente potencial de bromuro de metilo.
- Para cuantificar las emisiones de bromuro de metilo de varios escenarios de quema de biomasa.
- Evaluar la contribución de la quema de biomasa al presupuesto de bromo estratosférico.
Principales métodos:
- Realizó experimentos de laboratorio sobre la combustión de diversos tipos de combustible.
- Se analizaron las emisiones de humo para el contenido de bromuro de metilo.
- Se observaron columnas de humo de incendios forestales naturales en diferentes biomas (savana, chaparral, bosque boreal).
Principales resultados:
- El bromuro de metilo se detectó en el humo de los experimentos de combustión de biomasa de laboratorio.
- El bromuro de metilo también se identificó en columnas de humo de incendios forestales naturales.
- Las emisiones globales estimadas por la quema de biomasa oscilan entre 10 y 50 gigagramos por año.
Conclusiones:
- La quema de biomasa representa una fuente sustancial de bromuro de metilo, comparable a las emisiones oceánicas y el uso de pesticidas.
- Esta fuente previamente subestimada representa aproximadamente el 30% del presupuesto de bromo estratosférico.
- Los hallazgos destacan la importancia de considerar la quema de biomasa en los modelos atmosféricos y las evaluaciones del agotamiento de la capa de ozono.
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