Although tiny, microbes can have profound effects on the environment. New research out of the Scripps Institution of Oceanography in San Diego shows that ocean microbes could be contributing to global warming. In the study, two types of microbes were experimented with to determine their role in the formation of sea spray aerosol. Sea spray aerosol is the class of particles released from oceans that condense in the atmosphere to form drops of liquid out of which clouds form. Clouds are one controller of global temperatures. These microbes could be altering the chemistry of cloud cover all over the world changing their reflectivity.
In the lab, researchers found that marine bacteria consume phytoplankton, photosynthesizing ocean microbes that can releases various molecules including oxygen into the ocean. As the bacteria consume phytoplankton they release different particles as by-products into the surroundings, which eventually end up in clouds through sea spray aerosol. The type of particles varied depending on which type of bacteria was present.
It was previously known that phytoplankton provide over half of the worlds oxygen. They use sunlight as an energy source and take in dissolved carbon dioxide from the water and release oxygen as a by-product. Because of this and their high abundance in oceans, they are an important regulator of global temperatures so reducing their abundance may affect climate by causing increased carbon dioxide levels and decreased oxygen levels.
Finding out exactly how the composition of sea spray aerosol is affected by life has been difficult but scientists finally believe they know why. Nick Fellows, a professor at MIT for oceanography ho has been studying the same topic, stated, “The climate system is incredibly tied up with life,” in reference to the problem. Through this study, it has become clear the consumption of phytoplankton by marine bacteria has altered sea spray aerosol composition.
Microbes have always had a huge affect on climate throughout Earth’s history so the results of this study are not surprising. It was microbes, with similar metabolic pathways as phytoplankton that first provided oxygen to Earth’s early atmosphere while taking carbon dioxide out cooling temperatures billions of years ago. Although we cannot see microbes, they are everywhere and are vital to global temperatures.
Climate change is one of the biggest issues the world faces today and this research is a step in the right direction to understanding another reason why it is occurring.
The full article of the study can be found here: http://pubs.acs.org/doi/full/10.1021/acscentsci.5b00148 and is free to access.