University of Arizona professor Valerie Trouet named AAAS Fellow for pioneering climate research

In an era when understanding Earth’s climate past has become critical to predicting its future, University of Arizona professor Dr. Valerie Trouet has been named a fellow of the American Association for the Advancement of Science (AAAS), one of the world’s largest and most prestigious scientific societies. 

Trouet, who holds joint appointments in the Department of Hydrology and Atmospheric Science and the Laboratory of Tree-Ring Research at the U of A, is internationally recognized for her work using tree rings to reconstruct centuries of climate history. Her election to AAAS places her among a distinguished cohort of scientists honored not only for research excellence but also for advancing public understanding of science at a pivotal moment. 

“I was thrilled, of course, and really honored to be recognized,” Trouet said. “It was beyond what I could ever have imagined.” 

The recognition underscores the growing importance of paleoclimate science as researchers work to contextualize modern climate change within a much longer environmental record. Her research focuses on paleoclimatology and how large-scale atmospheric systems shape ecosystems and human societies. At the center of it is a deceptively small idea. 

Originally from Belgium, Trouet found her way to Tucson drawn by what she describes as the “mothership” of her field: the University of Arizona’s Laboratory of Tree-Ring Research. Since arriving, she has helped expand the reach of dendrochronology, applying it not only to environmental questions but also to the ways climate has intersected with human history. 

“We use the rings in trees to study history — the history of our climate, our forests, and even our own human history,” she said. 

Each tree ring captures a single year of growth, encoding environmental signals such as temperature, precipitation and fire. When analyzed across many trees and locations, those rings become a powerful archive, one that allows scientists to reconstruct patterns of drought, wildfire and atmospheric circulation across centuries. 

That long-term perspective, Trouet said, is essential for understanding the scale and speed of current climate change. 

“If you want to know how the climate varies in a natural way, you need to go back further in time,” she said. “Tree rings can do that.” 

Her research has also illuminated the extent to which human activity has shaped environmental systems long before the modern era. In California’s Sierra Nevada, Trouet reconstructed 500 years of wildfire history, revealing clear connections between fire patterns and major societal shifts, including the California Gold Rush and earlier waves of colonization that disrupted Indigenous land stewardship practices. 

“The moment we started measuring the climate with instruments is the moment we started messing with it at the same time,” she said. “Seeing those impacts of humans on fire history through tree rings — that was very surprising.” 

Beyond her research, Trouet is also recognized for her commitment to science communication. She has written books aimed at broad audiences and works to make complex climate science more accessible, which is something that she sees as essential in a time of growing skepticism.  

“Scientists are also people,” she said. “Showing that human side — showing excitement, showing what drives us — is really important for building trust.” 

Tree rings, she notes, offer a natural starting point for that connection. 

“Most people have looked at tree rings since they were a kid,” she said. “You start from something familiar and then you build on that.” 

Trouet’s path to the field began with a similar sense of curiosity. Growing up in Belgium with a father who was a cancer researcher, she was exposed to science early, but it wasn’t until her graduate work that she found her calling analyzing tree samples from Tanzania. 

“Looking at samples through a microscope is like solving a puzzle,” she said. “And then you realize you’re the first person to see something. You’re creating knowledge. There’s no feeling like it.” 

Today, her work spans continents, combining field expeditions, laboratory analysis and international collaboration in pursuit of ever-longer climate records. Her AAAS fellowship, she said, is both a personal milestone and a broader recognition of the field she has helped elevate. 

“I think tree-ring research is so exciting,” she said. “And being able to bring that to a broader audience — that really matters.” 

To learn more about Dr. Trouet and her research, click here.