# Current Fellows [### Karl Aspelund ](/people/karl-aspelund) Environmental Fellow: 2025-2027 PhD, Economics, Massachusetts Institute of Technology Karl M. Aspelund uses models grounded in economic theory, paired with spatial and administrative data, to design environmental policies that advance equity, efficiency, and sustainability.​ ​ Karl received his AB from Harvard College in 2017 in... ![a person smiling wearing a suit](/sites/g/files/omnuum10846/files/styles/hwp_4_5__690x865/public/2025-05/karl-aspelund01_crop.jpg?itok=aGcMS0X-) [### Camille DeSisto ](/people/camille-desisto)Environmental Fellow: 2026-2028 PhD, Ecology, Duke University Camille DeSisto is a quantitative ecologist and conservation biologist who studies forests undergoing environmental change. Camille DeSisto is a quantitative ecologist and conservation biologist who studies forests undergoing environmental change. Her... ![A photo of a blonde woman standing outside](/sites/g/files/omnuum10846/files/styles/hwp_4_5__690x865/public/2026-04/Desisto%2C%20Camille%20headshot.jpg?itok=qwrQ7UtV) [### Simon Greenhill ](/people/simon-greenhill)Environmental Fellow: 2026-2028 PhD, Agricultural and Resource Economics, University of California, Berkeley Simon Greenhill uses econometrics, machine learning, and economic theory to improve environmental measurement and management. Simon's research focuses on measuring environmental conditions, estimating causal relationships between environmental and human... ![A dark haired man in a blue suit](/sites/g/files/omnuum10846/files/styles/hwp_4_5__690x865/public/2026-04/Greenhill%2C%20Simon%20Headshot.jpg?h=b92144ec&itok=6TVnzxDr) [### Jong Yoon Jeon ](/people/jong-yoon-jeon)Environmental Fellow: 2026-2028 PhD, Forestry and Natural Resources, Purdue University Jong Yoon Jeon integrates genomic and geographic information to understand how threatened species respond to environmental change and strengthen their conservation assessments. Jong Yoon Jeon is a conservation scientist working at the intersection between... ![A photo of a dark haired man standing outside](/sites/g/files/omnuum10846/files/styles/hwp_4_5__690x865/public/2026-04/Jeon%2C%20Jong%20Yoon%20Headshot.jpg?h=c722e92f&itok=mOeyb5Yv) [### Jiameng Lai ](/people/jiameng-lai) Environmental Fellow: 2025-2027 PhD, Soil and Crop Science, Cornell University Jiameng Lai is an environmental scientist who integrates plant physiology theories, land surface modeling, satellite remote sensing, and data assimilation techniques to monitor, understand and predict the complex dynamics of terrestrial ecosystems in... ![A person smiling wearing glasses](/sites/g/files/omnuum10846/files/styles/hwp_4_5__690x865/public/2025-05/Jiameng.jpg?itok=LaBCfro8) [### Cameron MacDonald ](/people/cameron-macdonald) Environmental Fellow: 2025-2027 PhD, Atmospheric and Oceanic Science, Princeton University Cameron uses numerical models and theory to better understand the fundamental dynamics of Earth's atmosphere. ​ ​ Cameron received his B.Sc. in mathematical physics from the University of Waterloo in 2020. While working toward his undergraduate degree, he... ![A person smiling wearing a green shirt](/sites/g/files/omnuum10846/files/styles/hwp_4_5__690x865/public/2025-05/MacDonald.jpg?h=c0327943&itok=oaCOOVwQ) [### Kyra Morris ](/people/kyra-morris)Environmental Fellow: 2026-2028 PhD, English Literature, Princeton University Kyra’s work draws on poetics, aesthetics, and environmental studies to consider the ethical and ecological stakes of artistic form—how the forms we craft for the more-than-human world shape our ethical relationship to it. Kyra Morris earned her Ph.D. in... ![A photo of a brown haired woman wearing a white shirt](/sites/g/files/omnuum10846/files/styles/hwp_4_5__690x865/public/2026-04/Morris%2C%20Kyra%20Headshot.jpg?itok=stk8Yuw2) [### Nkosi Muse ](/people/nkosi-muse) Environmental Fellow: 2025-2027 PhD, Environmental Science and Policy, University of Miami Nkosi Muse utilizes a mixed methods approach to examine unique, humid heat hazards that threaten human health and productivity in urban areas, as well as develop policy solutions to equitably adapt in a warming world.​ ​ Nkosi earned a Bachelor of Science... ![A person smiling standing outside](/sites/g/files/omnuum10846/files/styles/hwp_4_5__690x865/public/2025-05/Muse%20Headshot.jpg?itok=F_bNo7jW) [### Christopher Yeh ](/people/christopher-yeh)Environmental Fellow: 2026-2028 PhD, Computing and Mathematical Sciences, California Institute of Technology Chris Yeh develops foundational algorithms and datasets for deploying reliable AI in critical energy, sustainability, and scientific applications, contributing theoretical insights with practical impact. Christopher Yeh is completing his PhD in Computing... ![A photo of a dark haired man wearing a light blue collared shirt](/sites/g/files/omnuum10846/files/styles/hwp_4_5__690x865/public/2026-04/Yeh%2C%20Christopher%20Headshot.jpg?itok=iioWM3iG) [### Guglielmo Zappalà ](/people/guglielmo-zappala) Environmental Fellow: 2025-2027 PhD, Economics, Paris School of Economics Guglielmo Zappalà applies statistical and econometric methods grounded in economic theory to traditional and geo-spatial satellite data to better understand the socio-economic impacts of climate change and humanity’s ability to adapt.​ ​ Guglielmo earned... ![A person wearing a blue sweater and standing in front of foilage](/sites/g/files/omnuum10846/files/styles/hwp_4_5__690x865/public/2025-05/Zappala%20headshot.png?itok=OP5B5ldI)