EES Professor Zunli Lu Awarded NSF Grant to Study the Causes of Mass Extinctions
Lu is part of an interdisciplinary team of scientists who will investigate how animals responded to environmental change millions of years ago.
It’s a human tendency to look at things through one’s own experience. However, this predisposition can be a weakness in the sciences, as reality is often composed of layered truths. Syracuse University geochemistry professor Zunli Lu describes the weakness of past studies of mass extinctions, moments in history when 75 to 90 percent of the earth’s creatures died off, as looking through a singular lens. “Two decades ago, people focused on one environmental change at a time. One group, studying temperature, might conclude that a change in temperature is what killed the animals. Another looked at a declining oxygen levels in the ocean, and then say, they suffocated; a lack of oxygen killed them,” says Lu.
This fall, Lu is part of a team of interdisciplinary scientists looking to better explain the causes of mass extinctions by combining these parameters, funded by a $2M grant awarded by the Frontier Research in Earth Sciences program of the National Science Foundation. “We put together a very impressive team,” says Lu. “Stanford and Syracuse are the lead of this project.” Also participating are scientists from University of Chicago, Princeton, Arizona State, and University of California, Riverside.
Considered some of the best in their fields, the team includes two additional geochemists, computer metabolic modeling experts, paleontologists, and Earth systems modeling experts. “We need to understand what the animals’ response was to the environmental change. The computer modelers can project a realistic world, describe what the environment used to be, in some cases, 200 to 400 million years ago. It’s not an easy thing to do,” says Lu.
One of the main goals of this project is to apply metabolic theory—the effect of temperature and oxygen on animal respiration—to a more quantitative study of these mass extinction events. “We can see how much temperature warming combined with how much oxygen loss can wipe out what kinds of animals at different latitudes,” says Lu. “These animals have different tolerances. What’s enough to wipe out tuna may not be enough to wipe out the clam. We will collect rocks and sediments in the field, bring them back into the lab, process those samples, do chemical analyses, and produce data, and those will be used to constrain the computer models.”
A greater understanding cannot come soon enough. Scientists estimate that a sixth mass extinction, the largest since the Creteceous-Paleogene extinction that took place 66 million years ago, has begun; what’s more, current die-offs are occurring, in some cases, hundreds of times faster than they have before, due to human-driven changes to the planet. “If we better understand how these catastrophic environmental changes drove these mass extinctions in the past, we can better understand the possible future trajectory,” says Lu. “When we talk about climate change, it’s not just about the weather. The ocean is turning acidic and losing oxygen. All of these things are related. The ecosystem will respond to this as a whole.”