Many scientists believe the Southern Ocean is responsible for absorbing up to half of all human carbon dioxide emissions. This is partly due to the plentiful, yet tiny organisms living at this Southern pole that play a large part in regulating the global climate, masking the full effect of human carbon dioxide emissions. If the warming climate causes them to die, the full power of climate change may be unleashed. Scientist in the lab, in the field, and robotic devices are working together to determine what will happen to these tiny polar creatures as the planet warms.
Stanford scientists are playing a role too. Senior Samantha Larson initially became interested in studying the tiny organisms that dwell in Antarctic sea ice when she learned, during a classroom lecture, that two particular species play a big role in global climate. These two species are the predominant Antarctic phytoplankton, tiny organisms that, like plants, use sunlight to produce their own food. The process of creating their food draws carbon dioxide from the atmosphere into the ocean, helping regulate the global climate.
Researchers don’t yet know how the phytoplankton will fare when the ice caps begin to warm. Will phytoplankton die or thrive in warmer seas? If they don’t survive, global warming may be more intense than predicted. Larson has been studying the future of these two dominant phytoplankton species.
As the global temperature increases, the sea ice in Antarctica is beginning to melt in many areas. Larson simulated the conditions of the warming ice in a Stanford laboratory in order to illuminate the microorganisms potential fate. The fresh water from the melting ice will make the Antarctic Ocean less salty and the reduced amount of ice will cause the ocean temperature to rise. Larson found that the salt levels in her incubations resulted in decreased health for both species, indicating that these tiny organisms in Antarctica may begin to die if sea ice continues to melt.
Unfortunately, if they die, they will no longer be drawing the carbon dioxide that society is emitting into the ocean. So, more carbon dioxide will remain in the atmosphere, worsening global warming. Though this result has dramatic implications, Larson emphasizes that this is just a single result in a highly controlled environment.
The importance of phytoplankton and their influence on the global climate is gaining attention in the scientific community. Stanford masters student Kate Lowry is studying their ecology in the earth’s polar oceans.
“Phytoplankton have big implications on the positive or negative feedback on climate change,” Lowry said. While studies like Larson’s help on the mission to understand the changing fate of these tiny organisms, Lowry believes that increased research in polar regions needs to be the next step.
What is actually happening to this phytoplankton is too complicated and poorly understood to be simulated in a lab. The ice is warming and many other things in their habitat are changing as a result.
“We need more measurements of what actually happens to phytoplankton when all of the factors change in the environment,” Lowry said.
As one might imagine, collecting samples in the polar oceans is no small task. Usually, recovering scientific data on an enormous research vessel from these regions is hard work and expensive. But as Lowry points out, “there are new technologies that can study wider areas for much cheaper.”
Lowry suggests the glider, a robot that travels under the water and is controlled remotely by scientists. The glider can collect continuous measurements for weeks at a time, around the clock. Already, many robotic devices are traveling in the world’s ocean collecting data that is being transmitted via satellite to scientists sitting comfortably in their offices.
The tiny organisms that dwell in the polar ice caps play a large part in mitigating the impacts of global warming. Their demise could lead to more dramatic warming for the entire planet. Yet, we still understand very little about how phytoplankton may respond to the warming oceans. Fortunately, rapidly improving technologies may soon shed light on this little understood relationship.