Oct 2, 2023 04:36 PM
https://arstechnica.com/science/2023/09/...ions-hazy/
EXCERPT: ... In a paper published this month in Science Advances, Dada’s team establishes a new heavy hitter in cloud creation: a kind of chemical released by trees. Trees emit natural volatiles like isoprene and monoterpenes, which can spark cloud-forming chemical reactions. Dada’s new work focuses on an overlooked class of less abundant volatiles called sesquiterpenes, which smell woody, earthy, citrusy, or spicy, depending on the molecule and type of plant or microbe that emits them.
The team shows that sesquiterpenes are more effective than expected for seeding clouds. A mere 1-to-50 ratio of sesquiterpene to other volatiles doubled cloud formation.
The role of trees in seeding clouds is important, because it suggests what the sky above some regions might be like if governments manage to tamp down sulfur emissions. In a world with less pollution, plants and trees will become more dominant drivers of cloud formation, an echo of the premodern world.
This research could help refine estimates of what the atmosphere was like before industrialization. Maybe we’ve been undercounting the world’s aerosol population by overlooking a large portion of those that come from trees. If so, climate models will need retooling.
“New particle formation is a pretty hot topic right now,” says Paquita Zuidema, an atmospheric scientist at the University of Miami who was not part of the study. “We’re coming to realize more and more that we don't really know exactly what a pristine atmosphere is like.”
While anthropogenic emissions dominate cloud formation in populated areas, plant volatiles dominate over more pristine land elsewhere. Lab tools have only recently become sensitive enough to understand which ones contribute the most.
Many discoveries about sesquiterpenes are relatively recent... (MORE - missing details)
EXCERPT: ... In a paper published this month in Science Advances, Dada’s team establishes a new heavy hitter in cloud creation: a kind of chemical released by trees. Trees emit natural volatiles like isoprene and monoterpenes, which can spark cloud-forming chemical reactions. Dada’s new work focuses on an overlooked class of less abundant volatiles called sesquiterpenes, which smell woody, earthy, citrusy, or spicy, depending on the molecule and type of plant or microbe that emits them.
The team shows that sesquiterpenes are more effective than expected for seeding clouds. A mere 1-to-50 ratio of sesquiterpene to other volatiles doubled cloud formation.
The role of trees in seeding clouds is important, because it suggests what the sky above some regions might be like if governments manage to tamp down sulfur emissions. In a world with less pollution, plants and trees will become more dominant drivers of cloud formation, an echo of the premodern world.
This research could help refine estimates of what the atmosphere was like before industrialization. Maybe we’ve been undercounting the world’s aerosol population by overlooking a large portion of those that come from trees. If so, climate models will need retooling.
“New particle formation is a pretty hot topic right now,” says Paquita Zuidema, an atmospheric scientist at the University of Miami who was not part of the study. “We’re coming to realize more and more that we don't really know exactly what a pristine atmosphere is like.”
While anthropogenic emissions dominate cloud formation in populated areas, plant volatiles dominate over more pristine land elsewhere. Lab tools have only recently become sensitive enough to understand which ones contribute the most.
Many discoveries about sesquiterpenes are relatively recent... (MORE - missing details)