Deep under the sea, a fossil the size of a sand grain is nestled among a billion of its closest dead relatives.

Known as foraminifera, these complex little shells of calcium carbonate can tell you the sea level, temperature, and ocean conditions of Earth millions of years ago.

Through ice ages and greenhouse climates, Katz has been able to piece together oxygen, carbon, and faunal data to paint a portrait of how, when, and why our climate has changed so drastically over geologic history.

In addition, her investigations into the deep past of Earth have important implications for understanding and tracking the potential drastic repercussions of modern, human-induced climate change.

"There is a saying among scientists in my field that 'the past is a window on the future,' " Katz said. "By reconstructing the climates of the past, particularly those where we see massive and rapid changes in the climate, we can provide a science-based means to explore or predict possible system responses to the current climate change."

While her work requires a lot of time in the laboratory, Katz has spent nearly two years at sea on seven different ocean voyages around the world to drill for foraminifera as part of the Integrated Ocean Drilling Program (IODP), an international marine research effort that explores the Earth's history and structure by looking at seafloor sediments and rocks.

During each two-month IODP excursion, Katz and the other scientists on board never set foot on land and spend hours poking through the millions of layers of sediment, trapped gases, fossils, and trace elements found in huge cores drilled from deep under the seafloor.

"Professor Mimi Katz studies these delicate deep-sea fossils to reconstruct the climates of Earth up to 250 million years ago. Known generally as foraminifera, these ancient organisms have a beautiful calcium carbonate shell that can be chemically analyzed to map out the Earth's sea level, temperature, and ice volume during their lives millions of years ago. (Credit: Rensselaer/Katz)"

Source: Rensselaer Polytechnic Institute