Knowledge & leadership for a sustainable future

Over the past seven years, George Gemelas ’18, '21 MEM has worked to educate people, mainly young Americans, about climate change, clean energy, and carbon dividends—the policy of putting a price on carbon emissions and returning the money directly to the people.

As a fellow at the Mitch Daniels Leadership Foundation, a development program for young professionals, Gemelas launched Build Clean Indiana to accelerate the clean energy transition in Indiana and inform fellow Hoosiers of business opportunities made available by continuing to grow the state’s clean economy. “Our strong business environment, our pragmatism, and our excellence in agriculture and industry will be needed to meet our country’s environmental challenges.”

Goal: Integrating environmental justice with ecological stewardship 

As a child, Landry Guillen ’25 MF lived near acres of farmland in California's arid Imperial County. The region is one of the country's leading agricultural producers but has been grappling with the effects of climate change, including persistent water shortages along the Colorado River. 

While attending the University of California, Santa Barbara, Guillen worked at the university’s urban farm and food bank and that led her to realize that circular food systems can play a major role in climate solutions.

Washington state is aiming to eliminate or offset its greenhouse gas emissions by 2050. Mike Johnson ‘16 MEM heads the auction process of the state’s cap-and-invest program, which has generated massive revenue for investments in climate resiliency, clean transportation, and other community programs.

“Washington taking action on climate change through a market-based approach not only creates financial incentives to reduce emissions but also drives innovation in energy production and carbon removal — whether through natural processes or engineered solutions. Our goal is an economy-wide transition away from carbon fuels, toward more efficient, equitable, and sustainable solutions.”

Goal: Decarbonize the energy sector globally in sustainable, scalable ways

Shubh Jain ’25 MEM first became interested in climate change through a class in documentary filmmaking. As an undergraduate initially majoring in physics at the University at Buffalo, Jain took a class with filmmaker John Fiege, who is known for his film and photography work on global ecology and environmental justice issues. Jain worked with Fiege on the production of “Raising Aniya,” a documentary about a young dancer’s life after Hurricane Harvey. 

Siria Gámez tracks big cats — all the way up 80-foot trees.  A doctoral student in YSE's Applied Wildlife Ecology lab, Gámez had special training to set up camera traps in the tree canopy of the El Triunfo Biosphere to examine how jaguars, pumas, and other carnivores use vertical spaces in the Sierra Madre de Chiapas mountains in Mexico.

“This particular region of Mexico is quite understudied,” says Gámez. “We’re exploring how these animals survive in this three-dimensional forest structure.”

Goal: Engage in sustainable business and development projects that empower local communities

Ever since she was a child, Mahica Iyer ’25 MEM has straddled two worlds: She grew up amid the glittering towers of Dubai, UAE. The community in her hometown of Mumbai, meanwhile, experienced frequent power outages, a scarcity of clean water, and poor waste management. Iyer later attended college in Illinois and then went on to work as a consultant in supply chain sustainability.

Researching natural ways to reduce greenhouse gas emissions, Ben Girgenti ’22 MESc tested whether adding minerals to wetland ecosystems can reduce biological methane emissions. After adding iron to the soil of mini wetlands, Girgenti found that methane was reduced by the mineral enhancement.

“If you’re building or using wetlands for natural carbon capture, you could shut off or decrease methane emissions, reducing the amount of time it takes for wetlands to begin having new sequestration of carbon,” Girgenti says.

Goal: Advancing Ghana’s transition to a net-zero economy

Benedicta Asiedu ’25 MEM has witnessed profound economic transformation in her home country of Ghana. It is one of the world’s largest exporters of gold, and it exports agricultural goods, most significantly cacao, to global markets. Since 2007, when oil in commercial quantities was first discovered, Ghana has also become a producer and exporter of crude oil. These three commodities alone have helped the country move from the edge of economic collapse three decades ago to, as the World Bank declared in 2019, the world’s fastest growing economy. (This growth has since slowed.)

Goal: Merge finance and water management for a more just and secure water future

According to the World Bank, the Global South could lose up to 6% of its GDP by 2050 due to water scarcity, with women and the poor most vulnerable.

Srishti Singh ’25 MEM is well aware of these, and many other, water-related challenges, as she most recently worked at India’s Central Pollution Control Board, where she was the sole social scientist on a team of physical scientists. “I realized I needed interdisciplinary training to become an effective leader in the water and climate space,” she says. “This led me to Yale.”

Goal: Work as a bridge between policymakers and academia to advance climate mitigation and adaptation strategies

Climate change poses a particular threat to island nations. Laura Polanco Valdez, who was born and raised in the Dominican Republic, understands this very well. Her homeland was ranked one of the 10 most affected nations by climate events between 1997 and 2016, according to the Global Climate Index. The pace of these events is only accelerating, and their scale increasing.

After Rae Wynn-Grant ’10 MESc studied bears in the Nevada mountains, the National Geographic Society sent her to conduct similar work with the American Prairie Reserve in the grasslands of Montana — a region where bears are not common.

The nonprofit is seeking create a national wildlife refuge. Wynn-Grant began working with carnivores while at YSE, tracking lions in Tanzania. She has leaned on her expertise to predict which habitats will attract bears, using state and federal data and camera traps to monitor bear movements and habitats.

As wildfires across the U.S. and Canada continue to endanger human health and wildlife, Pete Caligiuri ’10 MF, forest strategy director for The Nature Conservancy in Oregon, is working on fire suppression.

And these efforts include setting fires. “Frequent, extreme wildfires are a threat, but fire has to be part of the solution. Fire always has been a part of these landscapes. Beneficial fire — like prescribed burns and managed wildfires — is essential to the long-term resilience of these forest landscapes into the future,” Caligiuri says.

Jinali Mody ’23 MEM is reducing the environmental impacts from fashion with a new vegan alternative leather made from banana crop waste that the company says uses 90% less water in production than animal leather products and results in 90% less carbon emissions. “Solving the climate crisis requires concerted efforts across all industries and not just energy, transportation, and carbon capture. Building a sustainable fashion industry is the need of the hour,” says Mody. 

In 2023, Mody’s company, Banofi Leather, won the $1 million Hult Prize, which is given to student entrepreneurs whose ideas create a measurable positive impact on people and the planet. 

Charissa Rujanavech ’13 MEM is a tech industry innovator, developing novel ways to recycle and eliminate electronic waste. Shortly after graduating from YSE, she invented Liam, an automated disassembly system that can take apart more than 1 million iPhones a year so the components can be reused. She has continued her work in the circular economy, promoting a closed-loop supply chain for major retailers, including Amazon, and is now developing new technologies and partnerships to decarbonize refrigeration, retail operations, and food waste at Albertsons Companies.

Forests help mitigate climate change because of their ability to remove and store carbon dioxide from the atmosphere, but they become carbon emitters during wildfires. PhD student Reid Lewis '20 MF is researching how satellite data and machine learning models can help fire-prone forests become more resilient.

“When we make these forests more fire resilient, we can not only store more carbon, we can also help protect human communities, foster wildlife habitat, safeguard watersheds, and can use the process of restoration to partner with and empower Indigenous nations,” says Lewis.

Transitioning to clean energy is key to combating climate change. As director of policy and network at the Coalition for Green Capitol, Nenha Young ’20 MEM is targeting greenhouse gas reduction initiatives through investments in the environmental, social, and economic sectors and working to establish the National Green Bank.

“I attended YSE because of its leadership in the clean energy field,” Young says. “Through coursework, internships, and independent studies, I was able to design a career at the intersection of clean energy and economic development.”

After a decade as director of operations for Ghana’s Forestry Commission, overseeing the country’s commercial forest plantation development and land restoration,  Hugh Brown ’10 MF was named chief executive of the Ghana Forestry Commission in 2025.

The Commission has begun the restoration of more than 450,000 hectares of degraded forests and planted millions of new trees under Brown's leadership — part of a major reforestation initiative by the Ghanaian government to contribute to global climate action.

In July, Indonesia hosted the Y20 Summit, an annual gathering of youth leaders from G20 nations. This year's summit emphasized a sustainable and livable planet, and its recommendations will be presented at the upcoming G20 Summit in November. Caroline Tasirin ’19 MFS — a lecturer in the forestry program at Indonesia’s Sam Ratulangi University and co-founder of SULUT Semangat, a program that empowers Indonesian youths to connect with nature — represented the host nation and served as co-chair of the selection committee for Indonesia. “I'm proud to have contributed my insight and honored to collaborate with diverse youth leaders,” she says. 

As founding chair of the New York City Public Housing Authority Recycling Committee, DeNeile Cooper ’22 MEM is working to boost recycling efforts in public housing units.

Only 2% of waste from NYCHA units is recycled. Nationally, that rate is 32%.

“This work has been successful so far because it involves a variety of stakeholders who bring unique perspectives to create programs that work for everyone,” says Cooper, who is a member of the Manhattan Solid Waste Advisory Board.

At the end of 2021, Lia Nicholson ’14 MEM traveled to Glasgow, Scotland, on a mission with existential stakes. As the lead negotiator for the Alliance of Small Island States at the U.N.’s annual climate change conference, COP26, Nicholson represented the bloc of 39 small island nations, which together comprise 20% of all U.N. member states. While the numbers alone can seem abstract, the difference between a global temperature rise of 1.5° Celsius over the preindustrial baseline and a rise of 2° is “existential” for the vulnerable AOSIS nations that were among the first to have to reckon with the impacts of climate change nearly 30 years ago, she says.

As a YSE student, Morgan Pierce ’20 MEM did her summer internship at McDonald’s, where she worked with its global suppliers on strategies to reduce greenhouse gas emissions. After graduating she was hired as manager of strategy and alignment, where she has continued to address sustainability issues related to customers’ experience with dining and take-out.

“If we have YSE graduates like me sitting at the tables in these large organizations that control decisions on sustainability, then we can really be a catalyst of change,” Pierce says.