Climate scientists at the University of Rochester are using data science to understand what drives the global climate system—from deep in the ocean to high in the sky.
What do microscopic phytoplankton in the ocean have to do with climate change?
Plenty, according to Tom Weber, who studies the role of the small plants in the ocean carbon cycle as part of an effort to understand the global climate and its response to perturbations.
“That’s what really sparked my interest in this field: these tiny plants in the ocean can plunge the Earth in and out of huge climatic changes,” Weber says.
Weber uses large data sets collected at sea and by NASA satellite sensors to create numerical models to understand the interactions between marine ecosystems, elemental cycles, and the climate—and the effects of perturbations to that system. He specifically studies the suite of processes that transfers carbon from the atmosphere to the deep ocean, where it is sequestered out of contact with the atmosphere.
Phytoplankton pull carbon from the atmosphere into their biomass through photosynthesis, and pack the carbon into organic particles. These carbon-rich particles eventually sink from the surface ocean and are broken down by bacteria, releasing carbon dioxide. One of Weber’s recent projects includes modeling how deep the carbon sinks before it breaks down.
“That matters because if it breaks down in the shallow ocean, approximately 100 to 1,000 meters, it is circulated back to the surface and into the atmosphere on short time scales,” he says. “If the carbon reaches all the way into the deep ocean, then it’s stored down there for much longer time scales.”
The bacteria are sensitive to temperature and work more efficiently when it’s warmer. In a warming climate with warming ocean temperatures, bacteria break down carbon faster at shallower depths, and the carbon dioxide escapes back into the atmosphere instead of sinking deeper in the ocean.
He’s worried by what his evidence suggests.
“Humans are dumping way too much carbon dioxide into the atmosphere, warming the oceans, and perturbing the system much faster than natural variations ever have,” he says. “This is a problem given that humans and animals adapted to a particular climate system. If it changes over hundreds of thousands of years, they can adapt, but if things happen on much shorter time scales then there’s no time for ecosystems to adapt.”
Source: University of Rochester