John Kessler

John D. Kessler is a Professor and Department Chair in the Department of Earth and Environmental Sciences at the University of Rochester, part of the School of Arts & Sciences. He holds a PhD from the University of California, Irvine (2005), and has held academic positions at Texas A&M University and Princeton University. His research focuses on chemical oceanography, particularly methane and carbon dioxide dynamics in oceanic systems, with an emphasis on isotope biogeochemistry to understand climate change feedbacks. Kessler's work includes developing novel analytical techniques for measuring greenhouse gases and studying methane seepage, hydrates, and oxidation processes in diverse environments like the Gulf of Mexico, Arctic, and Great Lakes.

Key research interests include methane-climate interactions, ocean acidification, and the role of microbial oxidation in regulating greenhouse gas emissions. He has led over 15 funded projects as Principal Investigator or Co-PI, including NSF grants on methane oxidation kinetics and seep emissions. Notable awards include the Alfred P. Sloan Research Fellowship (2012) and the Goergen Award for Teaching (2015). Kessler advises graduate and undergraduate students, focusing on interdisciplinary approaches combining chemistry, geology, and engineering.

His fieldwork spans 25 expeditions, including 13 as Chief Scientist, with recent cruises in the Atlantic Margin, Gulf of Mexico, and Great Lakes. Kessler's lab has published extensively on methane dynamics, with over 50 peer-reviewed articles. He teaches courses like Chemical Oceanography and Stable Isotope Geochemistry, emphasizing climate change perspectives. His research has been highlighted in Science and Nature, including studies on the Deepwater Horizon spill’s microbial response and methane oxidation rates.

Scientific awards include recognition for his contributions to understanding methane’s role in climate systems. Grants include major NSF funding for developing automated greenhouse gas measurement techniques and constraining coastal methane emissions. Kessler’s interdisciplinary approach bridges analytical chemistry with environmental modeling, addressing critical global challenges in climate science and ocean health.