Ocean Microbes And Climate Change: How Marine Bacteria Are Spurring Global Warming

They may be tiny, but they pack a strong punch. Scientists are finding that the smallest ocean organisms can have a major impact on one of the biggest issues of the 21st century – climate change. New research has unpacked the role of phytoplankton and ocean bacteria in the formation of sea spray aerosol, the tiny particles that enter the atmosphere and help create the drops of moisture that form clouds, which control earth’s temperature. It shows that such microbes could actually moderate the chemistry of cloud cover, according to the study published Monday in the journal ACS Central Science.

The study provides new insight into the influence of the ocean microbes on atmospheric conditions and could help scientists better predict climate change, according to researchers from Scripps Institution of Oceanography in San Diego, which led the study. “It is exciting to finally be able to find a connection between microbes in seawater and atmospheric sea spray,” Kimberly Prather, lead author of the study, said in a statement. “These chemical changes ultimately affect the reflectivity of marine clouds and thus could have profound impacts on climate over a large portion of the planet.”

Researchers experimented with phytoplankton blooms in a lab. They found that as marine bacteria consume phytoplankton, microscopic organisms that inhabit the upper layers of the oceans and survive by photosynthesizing, they release certain molecules into the atmosphere. Such molecules varied depending on the type of bacteria involved. Waves end up launching these molecules into the air, where they form clouds.

Previous research has shown that phytoplankton provide more than half of the world’s supply of oxygen and play a key role in regulating the planet’s climate. But pinpointing exactly how these tiny organisms affect atmospheric conditions has been difficult.

"The climate system is incredibly tied up with life," Mick Follows, an associate professor of oceanography at the Massachusetts Institute of Technology in Cambridge, Massachusetts, told Phys.org in April. Follows' research has dealt with this very topic of incorporating the role of ocean microbes in climate change models.

"You can think of man in the same way as those first photosynthetic bacteria that changed the planet in a radical way, to a completely different set of requirements if you wanted to survive on that planet,” he said. “Are we that thing now? Or are we a blip? It's interesting to put it in perspective."