05 May 2015:
Pollen May Play Surprising
Role in Climate and Cloud Formation
Grains of pollen can break into even smaller particles.
Grains of pollen may be seeding clouds and affecting the planet's climate in unexpected ways, University of Michigan researchers write in the journal Geophysical Research Letters
. Scientists had assumed that pollen particles were too large to remain in the atmosphere long enough to interact with the sun's radiation or trigger cloud formation. The study found, however, that pollen grains are capable of disintegrating into much smaller particles — something that allergy researchers have known for quite some time — and that exposure to humidity can accelerate pollen's breakdown. Using a cloud-making laboratory chamber, the researchers showed that six common types of pollen — ragweed and oak, pecan, birch, cedar, and pine trees — could break into particles small enough to pull in moisture and form clouds. "What happens in clouds is one of the big uncertainties in climate models right now," lead researcher Allison L. Steiner said. "One of the things we're trying to understand is how do natural aerosols influence cloud cover and precipitation under present day and future climate."
Yale Environment 360 is
a publication of the
Yale School of Forestry
& Environmental Studies
Yale Environment 360
articles are now available in Spanish and Portuguese on Universia
, the online educational network. Visit the site.
Business & Innovation
Policy & Politics
Pollution & Health
Science & Technology
Antarctica and the Arctic
Central & South America
A look at how acidifying oceans could threaten the Dungeness crab, one of the most valuable fisheries on the U.S. West Coast. Watch the video.
is now available for mobile devices at e360.yale.edu/mobile
An aerial view of why Europe’s per capita carbon emissions are less than 50 percent of those in the U.S. View the photos.
An indigenous tribe’s deadly fight to save its ancestral land in the Amazon rainforest from logging. Learn more.
video series looks at the staggering amount of food wasted in the U.S. – a problem with major human and environmental costs. Watch the video.
Residents of the Chocó Rainforest in Ecuador are choosing to plant cacao over logging in an effort to slow deforestation.
Watch the video.
Tribal people and ranchers join together to stop a project that would haul coal across their Montana land. Watch the video.