This picture from an electron microscope shows a type of plankton. These plankton give off chemicals that have sulfur in them. The chemicals make tiny particles in the air. Those particles can change Earth's climate!
Click on image for full size
Image courtesy of NASA/JPL, photograph by Stefan Gartner.

Sulfate Aerosols from Plankton

Aerosols are tiny particles or drops of liquid that float around in the atmosphere. For example, tiny flecks of smoke particles from fires or smokestacks are a type of aerosol. Some kinds of aerosols come from the ocean. Small particles of sea salt are thrown into the air by the spray from waves. Some microbes that live in the ocean give off chemicals that make aerosols, too.

Some types of plankton release chemicals that have sulfur in them. As these chemicals rise up into the air they can be turned into very small droplets of sulfuric acid! Chemical reactions in the atmosphere can turn this acid into various types of aerosol particles.

These tiny aerosol particles actually affect Earth's climate! Some particles reflect and scatter sunlight. Less sunlight makes it to the ground. That makes Earth just a little bit cooler. The aerosols also cause changes in clouds. They can cause more, smaller droplets to form, which makes it harder for the clouds to rain. Clouds that "hang onto" their water tend to last longer. Bright, white clouds also reflect sunlight away. That cools down Earth, too.

How can tiny microbes change the climate of a whole, huge planet? Remember that more than two thirds of Earth's surface is covered by oceans. That means there are trillions and trillions of microscopic plankton floating around. Plankton are by far the biggest natural source of aerosols which contain sulfur.

Humans also make lots of sulfur aerosols. The coal and other fossil fuels we burn make sulfur aerosols. Scientists think that about 70% of sulfur aerosols are made by humans. About 20% are made by microbes in the seas. Scientists who study Earth's climate want to know as much as they can about aerosols. That's why they are interested in studying all of the places aerosols come from.

Last modified October 27, 2008 by Jennifer Bergman.

You might also be interested in:

Traveling Nitrogen Classroom Activity Kit

Check out our online store - minerals, fossils, books, activities, jewelry, and household items!...more

Aerosols: Tiny Particulates in the Air

When you look up at the sky, you are looking at more than just air. There are also billions of tiny bits of solid and liquid floating in the atmosphere. Those tiny floating particles are called aerosols...more

Salinity

About 70% of the Earth is covered with water. Over 97% of that water is found in the oceans. Everyone who has taken in a mouthful of ocean water while swimming knows that the ocean is really salty! Dissolved...more

Sea Salt Aerosols

If you've ever been to the ocean, you know that ocean water has salt in it. But did you know that air has salt in it, too? Many types of tiny particles float around in the air. Scientists call these particles...more

Kingdom Protista

Members of the Kingdom Protista are the simplest of the eukaryotes. Protists are an unusual group of organisms that were put together because they don't really seem to belong to any other group. Some protists...more

Sulfuric Acid - H2SO4

Sulfuric acid is a very common type of acid. Acid rain has sulfuric acid in it. Acid rain harms plants, fish, and other living things. A type of air pollution causes acid rain. When people burn fossil...more

Atmospheric Chemistry of Earth's Troposphere

When you think of chemistry, do you think about mixing colored liquids in test tubes and maybe making an explosion... or at least a nice puff of smoke? Did you know that a lot of chemistry happens in Earth's...more

Earth's Radiation Budget

Light from the Sun shines on Earth. Some of that light reflects off clouds back into space. Some of the light makes it to the ground and warms our planet. The warm ground and oceans give off infrared (IR)...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA