2023-2024: Paleoceanography and Paleoclimatology: Jessica Tierney

Jessica E. Tierney 
University of Arizona 


Jessica Tierney is a Professor of Geosciences and the Thomas R. Brown Distinguished Chair in Integrative Science at the University of Arizona. She specializes in reconstructing past climate change using molecular biomarker methods and statistical techniques so that we can better understand future climate change. She was a Packard Foundation Fellow and received the Alan T. Waterman award from the National Science Foundation in 2022. She was also a Lead Author of the IPCC AR6 Working Group I report released in 2021.

Abstract: Past Climates Inform our Future

As humans burn fossil fuels and raise the concentration of greenhouse gases in our atmosphere, the climate is changing—fast. All around us, we are experiencing climate change in the form of hotter temperatures and more extreme weather events, including droughts, floods, and heat waves. What does the future have in store for us? To answer this question, we must query the geological past. The last time that carbon dioxide was at present-day levels was over 2 million years ago—a time well before humans walked the Earth. Ancient warm climates like this one hold the key to understanding how higher greenhouse gas concentrations alter land and sea ice, and patterns of warming and rainfall. We can piece together what happened in the deep past by using natural archives of climate change as well as computer simulations. As we’ll discuss, the lessons of the past can directly inform our future climate trajectory, giving us a glimpse of how the planet will behave along different emissions scenarios.