Student Name
Date
Block
“Dirty Air Fosters Precipitation Extremes”
By Janet Roloff
Time Magazine
September 12, 2011
Summary: Scientists have studied clouds and found that aerosols, a class of pollutants,
can have an extreme effect on rainfall patterns. When aerosols from polluted air are sucked into
clouds, they can alter when the cloud will deposit rain. As the first study to “clearly establish the
link between aerosols, precipitation, and climate”, scientist Zhanquig Li reports that a monitoring
instrument in the western US has collected data about clouds over the past 10 years. This
evidence has shown that polluted air has effected clouds. Water and aerosol molecules collect
and grow until there are enough droplets to fall as rain. But what scientist Li found was that
when too many aerosol molecules were in a cloud, the cloud could not produce large enough
water droplets to fall as rain. Although global warming is something that we know has had a
huge impact on our Earth’s extreme weather, we now know that there is more than one factor
causing global warming.
Response: Overall, I found this article very interesting. I know global warming has been
a huge issue in the world, and greatly affects Earth’s future. There’s always lots of talk about
how the world will end soon, and so on. Also, extreme weather conditions have been a huge
issue lately. We have had hurricanes and earthquakes happen in the same year, and suddenly it’s
snowing in October. It was interesting to find that one of the things causing these extreme
conditions is aerosol in the clouds. Before reading this article, I didn’t know how pollution
formed in clouds. Now I have a very clear picture in my mind of what happens to create clouds.
One question I still have is what types of aerosols are in the air around us? I’m excited to learn
more about global warming so I can learn what I can do to help out the Earth and reduce the
amount of pollution in the air.