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Knowledge & leadership for a sustainable future

Class of 2023 group photo outside Kroon Hall

The YSE Class of 2023: Ready to Meet the Challenges Ahead with a ‘Sense of Purpose, Possibility, and Patience’

With optimism and determination, YSE graduating students celebrated their accomplishments, promising to take time to invest in complex climate initiatives and work to ensure that all marginalized voices are heard.


News & Research

Parked cars beside curbside EV chargers

Advances in Technology are Driving Popularity of EVs

New research led by the Yale School of the Environment demonstrates that improvements in battery range and costs is behind the rise of electric vehicle sales.

Highlights from the 2023 YSE Research Day

From the impacts of habitat fragmentation on gray wolves in the American West to innovations in sustainable gold mining, students share their research findings at YSE’s 39th Annual Research Day.

Environmental Policy & Practice Impacts

At the Yale School of the Environment, our work directly impacts environmental policy and practice and helps to solve local and global environmental challenges.

Looking over a river and hillside forest to a mountain in the American west

Linking Nature and the Economy

At the White House Office of Science and Technology (OSTP), Eli Fenichel, Knobloch Family Professor of Natural Resource Economics, led a 27-agency team that drafted “National Strategy to Develop Statistics for Environmental-Economic Decisions,” a framework for the multi-year effort to use data to better understand nature’s critical contributions to the U.S. economy. 

A person on the street, seen from behind, holding up the flag of Ireland

Engaging the World in Climate Solutions

The Yale Program on Climate Change Communication works with governments, media organizations, companies, and civil society organizations in the U.S and around the world to build public and political will for climate solutions. They partnered with the Irish Environmental Protection Agency to produce  maps of Ireland detailing how climate change beliefs, risk perceptions, and policy support vary at the county and regional levels as part of the Irish government’s effort to develop a national strategy to engage its population in climate change solutions.

A school of ocean fish seen from below

Advancing Novel Natural Climate Solutions

In 2010, Oswald Schmitz, Oastler Professor of Population and Community Ecology, developed the Animating the Carbon Cycle (ACC) concept, which maintains that healthy populations of wild animals, both terrestrial and marine, can play a significant role in boosting the ability of ecosystems to store carbon, helping the planet stay within 1.5°C (2.7°F) of temperature rise over pre-industrial levels. Interest in ACC as a natural climate solution has continued to grow in the scientific and policy communities, and it was included in the Action Plan for the UN Decade on Ecosystem Restoration, 2021-2030. 

A container ship docked in port at night

Aligning Trade Policy with Sustainability Goals

Hillhouse Professor of Environmental Law and Policy Daniel Esty is currently working with World Trade Organization Director-General Ngozi Okonjo-Iweal to develop a sustainability agenda for a trading system that better aligns the WTO with the world community’s commitment to achieve net-zero greenhouse gas emissions by 2050. Find out more about his work in the 2023 issue of Canopy magazine. Available in print and online in June.

International flags outside the UNIDO building in Vienna, Austria

Creating a Global Green Chemistry Network

The Center for Green Chemistry and Green Engineering at Yale is leading a U.N.-backed initiative, the Global Greenchem Innovation and Network Programme, that will greatly accelerate research, development, and training in green chemistry in Indonesia, Jordan, Peru, Serbia, Uganda, and Ukraine. By establishing accelerator programs in emerging nations, the GGINP aims to reduce greenhouse gas emissions and persistent organic pollutants (POPs) — “forever chemicals” that can be harmful to human and ecosystem health. Learn more in the 2023 issue of Canopy magazine. Coming in June.

Reverse osmosis machine in use

Helping Regional Maple Syrup Producers Adapt to Climate Change

Sugar producers in New England, who are under increasing pressures from climate change, can learn about sustainable maple syrup production through a training program offered by The Forest School at YSE. The Maple Education and Extension Program hosts training workshops focusing on sustainable management of sugarbushes for companies and students at Yale-Myers Forest in northeastern Connecticut. The program is also producing its own maple syrup and is expected to yield at least 50 gallons of syrup this year. 

Degrees & Programs

The Yale School of the Environment offers a variety of degree programs, many of which can be customized to meet each student’s professional goals, and prepare them for careers in environmental science, management, and policy.

Master’s Program

Apply to a Master's Program

Meet Our Alumni

Nenha Young

Financing the Transition to Clean Energy

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.”

Ben Girgenti

Experiments in Reducing Methane Emissions

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.

Ki’ila Salas

Restoring Belize’s Landscapes

Ki’ila Salas ’19 MF returned to her home country of Belize to participate in its first landscape restoration initiative, helping to develop its National Landscape Restoration Strategy for the Belize Forest Department. The project is part of the country’s national restoration commitment to the Bonn Challenge, which has a global goal to bring 350 million hectares of degraded and deforested landscapes into restoration by 2030.

“The project gave me great pride and joy in guiding the process of how the restoration strategies should be accomplished,” Salas says.

Siria Gamez in a climbing harness placing a camera in the tree tops

Tracking Big Cats in the Sierra Madres Mountains

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.”

Caroline Tasirin at Y20 Indonesia

Empowering Young Leaders

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. 

Deneile Cooper speaking at a Housing Authority event in New York City

Waste Warrior

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.

Rae Wynn Grant photographed by Tsalni Lassiter

Tracking Bear Movements

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.

Lia Nicholson

Speaking for the Islands

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.

Hugh Brown under a canopy of bamboo

Rehabilitating Ghana’s Forests

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 executive director of the Commission's Forest Services Division in 2022.

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.

Morgan Pierce

Greening the Supply Chain

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.

Ian Leahy standing beneath a ginkgo tree

Tree Equity

Using income, age, ethnicity, health, and surface temperature data and tree canopy surveys, Ian Leahy ’21 MEM, vice president of urban forestry at American Forests, helped create a Tree Equity Score. Wealthy urban communities, it found, have 65% more tree cover than low-income neighborhoods where temperatures can range 10 degrees higher.

The issue is a matter of health, Leahy noted in a New York Times Op-Ed., and his efforts have led to more financial support for urban tree growth. “What we're trying to do right now,’’ he says, “is close the canopy gap to save lives.’’

Leigh Whelpton

Where Capital Meets Conservation

The art and science of raising and deploying capital for conservation is at the heart of the work being done by Leigh Whelpton ’12 MESc. She is executive director of The Conservation Finance Network. “You often hear people talk about how there’s not enough money,” says Whelpton. “That’s not quite true. It’s a lack of capacity and connection, a lack of risk-adjusted return opportunities, and a limited supply of projects that can meet the requirements for financing. We focus on increasing the project pipeline and scaling up capacity to get more money on the ground.”

Dechen Dorji in the high mountains

Keeping Bhutan Carbon Neutral

To make good on its constitutional mandate to be the first carbon neutral country for its entire existence, Bhutan relies heavily on its forest cover. Dechen Dorji ’01 MEM led the Bhutan for Life initiative, which raised more than $40 million to finance the protection of the country’s pristine network of protected areas.

Dorji continues to work on land preservation and protection of endangered species as the World Wildlife Fund’s senior director for the Asian Wildlife Program.

Fast Facts

2023 Incoming Cohort


International Students

40% of the 2023-2024 master's cohort are from outside the United States.


Receive Financial Aid

92% of incoming master's students who completed the YSE aid application will receive financial aid.

2023 Incoming Masters


5+ Years Work Experience

21% of incoming master's students have more than five years of work experience.


Age Range

Incoming master's students range in age from 21 to 54 years old with an average age of 27. 

2023 Incoming Cohort



Students come from 32 countries and 32 states and U.S. territories.

Centers, Programs & Initiatives

Students measuring the height of grass in a grazing field
Ucross High Plains Stewardship Initiative

192 Partners

The Ucross High Plains Stewardship Initiative has collaborated with more than 192 external partners during the past five years, giving students hands-on experience while building conservation capacity in the American West.