CMI Best Paper Awards recognize postdoc, graduate student published research

Holly Welles ・ Carbon Mitigation Initiative

The Carbon Mitigation Initiative (CMI) recognized Jane Baldwin, a past postdoctoral fellow in the Princeton Environmental Institute (PEI), and Samantha Hartzell, a graduate student in civil and environmental engineering, at the CMI Annual Meeting for outstanding published research. Baldwin received the Robert H. Socolow Best Paper Award for Postdoctoral Fellows and Hartzell was the inaugural recipient of the Robert H. Socolow Best Paper Award for Doctoral Students.

Since 2010, CMI has presented best paper awards to postdoctoral fellows working with CMI faculty members based upon their contributions to important CMI papers. CMI created a similar award for doctoral students in 2019. Both awards are named in honor of Robert Socolow, professor of mechanical and aeronautical engineering, emeritus, at Princeton and the codirector of CMI from 2000-2019. CMI is an independent academic research program based at Princeton and administered by PEI that includes 16 principal faculty investigators and over 50 research staff.

Samantha Hartzell (left) and Jane Baldwin.

Baldwin, currently a postdoctoral research fellow at Columbia University’s Lamont-Doherty Earth Observatory, was recognized for her paper, “Temporally Compound Heat Wave Events and Global Warming: An Emerging Hazard,” published in the journal Earth’s Future in 2019. She worked on the study during her PEI postdoctoral position in the laboratory of CMI principal investigator Gabriel Vecchi, professor of geosciences and the Princeton Environmental Institute.

Baldwin, who received her doctorate in oceanic and atmospheric sciences from Princeton in 2018, studies how atmospheric dynamics influence regional climate, with a focus on climate change and policy applications. Heat waves are projected to become longer, more numerous, and more intense with global warming, she said. In her study, she and her coauthors analyzed physics-based simulations of Earth’s climate and temperature observations to provide the first quantifications of the hazard from compound, or back-to-back, heat waves.

Previous studies had not considered the implications of multiple heat waves occurring in sequence, she said. “We demonstrate that compound events will constitute a greater proportion of heat wave risk with global warming,” Baldwin said. “This has important policy implications, suggesting that vulnerability from prior heat waves will be increasingly important to consider in assessing heat wave risk and developing heat wave warning systems.”

Hartzell was awarded for her paper, “Unified Representation of the C3, C4 and CAM Photosynthetic Pathways with the Photo3 Model,” published in the journal Ecological Modelling in 2018. Hartzell currently studies in the laboratory of CMI leadership team member Amilcare Porporato, the Thomas J. Wu ’94 Professor of Civil and Environmental Engineering and the Princeton Environmental Institute.

Hartzell’s paper compares and consistently models three photosynthetic pathways that plants use: C3, C4 and CAM. The traditional pathway, C3, is used by most of the crops we eat and is the most water intensive. C4 is the “turbocharged” pathway that uses 25% less water by concentrating carbon dioxide to improve light-use and water efficiency in grasses and related plants. The drought-tolerant CAM pathway assimilates CO2 at night and stores carbon to increase water-use efficiency in dryland plants and rainforest canopies, using 6-10 times less water than C3.

Hartzell’s paper also introduced the Photo3 model, which represents all three pathways in an integrated manner. “This approach will enable the incorporation of CAM plants into global climate models for the first time, enhancing the ability to analyze carbon and water fluxes in tropical and dryland ecosystems,” Hartzell said. “Moreover, this facilitates quantification of water use and productivity trade-offs between the three pathways.”