Study: Tiny plankton

One more step towards understanding the science of plants, trees cooling on the Earth and how we can use natural vegetation, and the engineering around it, to expand our canopy.

Always, there is opportunity to license this knowledge into the commercial realm. 

Study: Tiny plankton play a big role in keeping the earth cool

Katherine Ellen Foley



Phytoplankton: out to save the planet?

In the middle of the world’s southern ocean, there’s a mighty force that’s helping keep the sun’s rays at bay. The force is so small that it can’t been seen with the naked eye: phytoplankton.

That force, phytoplankton, consists of teeny, tiny little plants that live in the shallow depths of the ocean around the world. Recently, scientists from the University of Washington and the Pacific Northwest National Lab found that phytoplankton help reflect (paywall) some of the sun’s rays back into space by changing the composition of certain clouds.

“If you were to turn off clouds altogether in the southern ocean in January, you can estimate…that clouds change the reflected shortwave by about 125 Watts per square meter,” Daniel McCoy, a graduate student at the University of Washington and co-author of the paper, told Quartz. This research showed that aerosols produced by plankton account for 10 Watts per square meter. “Just having biogenic aerosols there change it by [a factor of] 10.”

In other words, microscopic plants are helping to keep temperatures around the southern ocean a lot cooler.

In the ocean, phytoplankton produce organic chemicals that make their way up into the atmosphere through sea spray. Susannah Burrows, an atmospheric scientist at the Pacific Northwest National Lab and co-author of the study, explained that it’s a similar phenomenon to the way salt gets all over our bodies at the beach.

The researchers explained that in order for clouds to form, individual cloud droplets need to have a particle to surround. The organic aerosols from plankton are the perfect size. Assuming the cloud size and the amount of water vapor in them are the same, clouds formed with aerosols from plankton will have many more droplets, which explains their additional reflective properties.

Humans and other plants in forests emit aerosols all the time, but the resulting clouds aren’t as reflective as the ones formed with plankton aerosols. The more reflective clouds are, the less the sun’s energy reaches our planet to warm temperatures.

Burrows explained that although this research doesn’t definitively indicate that phytoplankton are fighting global warming, it does give scientists clues about how humans are affecting cloud formation. “We need a good representation of the good natural background aerosol,” she tells Quartz.

Burrows thinks this research will help scientists understand how human activity has been changing the atmosphere.