As the Northeast faces an ongoing drought and, like many areas of the U.S., adapts to an increased wildfire risk, Dartmouth Master of Energy Transition faculty member Christopher Guiterman, PhD brings an extended view to understanding how our climate and ecosystems have changed over time.
A dendrochronologist and climate scientist, Guiterman studies tree rings to examine how forests respond to fire, land use, and climate. His research offers surprising insights—among them, that the country has actually experienced an 80–100 percent decrease in the area burned by wildfire over the past century.
"Prior to 1900, there was way more fire in just about every forest ecosystem than there has been since," explained Guiterman. "This is largely due to changing land use and fire management practices."
Understanding climate science and wildfires is essential for advancing the energy transition. In a changing climate, increased wildfire risks pose threats to grid reliability and resilience, highlighting the need for sustainable, adaptive energy systems that can withstand and respond to environmental challenges.
One of the best indicators of fire history is found in tree ring samples, which reveal many aspects of a tree's life, including exposure to fire. In addition to his work at Dartmouth, Guiterman also serves as a Research Scientist with the Cooperative Institute for Research in Environmental Sciences (CIRES) at the University of Colorado Boulder. CIRES is a partner of the National Oceanic and Atmospheric Administration (NOAA), working collaboratively with the National Centers for Environmental Information (NCEI). On the NOAA-NCEI Paleoclimate team, Guiterman and his colleagues operate the World Data Service for Paleoclimatology, which provides over a dozen archives of Earth's climate and environmental history for researchers and the public to access.
As the team's dendrochronologist, Guiterman specifically investigates the history of climate in relation to fire—using tree rings to reconstruct past environmental processes. Focusing on the drivers of changing forest dynamics—including climate change and human land-use—he works to understand why wildland fire has become problematic in key areas, and how forest and fire managers can mitigate the effects of climate change on forests.
"In addition to tree rings, we look at ice cores, and charcoal and pollen sediment in lakes and bogs," detailed Guiterman. "These samples tell the story of human-fire relationships — interactions among fire, people, vegetation, and climate."
Over the past six years, Guiterman and fellow researchers have built the North American Fire Scar Network, compiling samples from more than 2,500 fire history sites across North America. Using this dataset, they analyzed broad patterns of fire history and reported on their findings in Nature Communications earlier this year: A fire deficit persists across diverse North American forests despite recent increases in area burned.
At Dartmouth, Guiterman serves as a Lecturer at the Guarini School of Graduate and Advanced Studies and a Visiting Scholar in Dartmouth's Department of Earth Sciences. This fall, he is teaching Climate Science and the Energy Transition in the Master of Energy Transition (MET) program.
The course focuses on climate science, the drivers of climate change, and their impacts on society and ecosystems.
"We explore the effects of climate change and how climate change mitigation programs—such as reducing greenhouse gases through practices like switching to carbon-free energy sources or carbon capture and storage—affect the climate system," shared Guiterman. "We have a strong focus on scientific literacy—in recognizing misinformation, evaluating scientific information, and understanding the process of conducting science."
As MET students investigate the challenges and opportunities of the clean energy transition, Guiterman emphasizes that a deep understanding of climate science is essential.
"It's crucial that we understand the interconnectedness of energy systems and the climate," he noted. "The MET students are future leaders of the energy transition, and I want them to know where their efforts could have real benefits to some of the human and natural communities most affected by recent rapid warming. "
Providing MET students with a solid foundation in climate science, he added, also strengthens their motivation to advance the energy transition.
"The momentum of climate change is only accelerating despite mitigation efforts," Guiterman remarked. "If we don't hit the brakes on carbon emissions and change our energy sources, a lot of what we hold dear on Earth—in terms of ecosystems and our future—is at risk."
"We're so grateful to have Chris's expertise in the Master of Energy Transition program," shared Amanda Graham, MET Program Director and Director of Academic Programs at the Irving Institute. "One of the goals of his course is for students to learn to be wise consumers of climate science. It's so important for anyone working in the energy transition to have a clear understanding of how energy systems are impacting the climate—and how to interpret the data that shows those impacts."
This fall, MET students in Guiterman's course have been engaging in team projects that apply their learning to real-world problems. One group is working with The Citrin Family GIS/ASA Laboratory, led by Assistant Professor Jonathan Chipman, to analyze data and investigate patterns of warming temperatures and changing precipitation dynamics on Mount Washington. It's part of the lab's broader collaborative efforts with the Appalachian Mountain Club (AMC) to understand long-term environmental change in the alpine zones of mountains in the northeastern U.S. and eastern Canada.
Another group is partnering with the Dartmouth Skiway to improve the efficiency of snowmaking operations amidst warming winter temperatures, and in tandem with the energy transition.
"We're analyzing the seasonality of weather windows that are vital for snowmaking operations—are we getting fewer snowmaking days? When do they fall? What could that look like going forward?" said Guiterman.
Through these partnerships, students are connecting climate science with everyday energy and operational challenges across the Upper Valley and northern New Hampshire, getting hands-on experience in how local organizations adapt to a changing climate.
Guiterman's current research also brings him closer to home. He is collaborating with a team at Plymouth State University to reconstruct the fire history around North Conway, New Hampshire, tracing back more than 12,000 years, since deglaciation.
By analyzing the history of fire, regional and state teams can better shape their strategies to reduce future risk.
"We have an opportunity to manage fire now," noted Guiterman. "If the climate shifts and makes things more flammable, this will be time well spent."