Master of Environmental Science or Master of Forest Science — MESc or MFS

Develop critical research skills and learn grant-seeking strategies in these highly individualized programs.

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    Program Overview

    The Master of Environmental Science and Master of Forest Science programs are designed for students wishing to conduct scientific research that contributes basic and applied knowledge. These highly individualized two-year degrees offer a deeper disciplinary focus on forest-related topics (MFS) or other environmental issues (MESc) through formalized training in the philosophy and practice of science. Training is provided through key courses in combination with extended research. Students in the MFS/MESc programs have the opportunity to develop critical research skills, pursue self-directed research, learn and practice grant-seeking strategies, and create a publication-ready master’s thesis to be presented to the broader Yale community.

    Advisor Relationships

    Faculty research advisors play a key role in the MFS/MESc program. In addition to overseeing their scientific research, advisors collaborate with students to design and approve their unique course of study. Faculty provide guidance in selecting courses to support the design, execution, and communication of students’ master’s research and align with students’ career goals. They also serve as a resource during the process of proposing and completing the master’s thesis.

    Note: Applicants should connect with potential advisors before applying to the program. When applying, applicants will be asked to submit the names of three faculty members with whom they are interested in working. Advisors will be selected from that submitted list upon admission to the program.


    Why choose the Yale School of the Environment?

    Students on a field trip at a water treatment facility

    Experiential Learning

    At YSE, education and training extend well beyond the classroom. Participate in our unique summer orientation program, MODs; travel widely for field research and internships; attend global conferences and climate talks such as the U.N. Climate Change Conference (COP 26).

    Professor Marian Chertow with a student at Commencement

    Acclaimed Faculty

    Working closely with some of the top experts in their fields is one of the advantages of a YSE graduate degree. Our faculty are committed to mentoring the next generation of environmental leaders to tackle the world’s most urgent problems.

    Student and Alumni Impacts

    Yufang Gao in the mountains

    Redefining Human-Wildlife Conflict

    In the Tibetan Plateau, Yufang Gao ’14 MESc, ’23 PhD interviews, observes, and travels with Tibetan herders and Buddhist monks. He sets up camera traps and collects scat to analyze the diet of snow leopards. And he has hiked a mountainside 15,000 feet above sea level — all in pursuit of data for his dissertation focused on the quest for harmonious coexistence between people and large carnivores. What is needed for human-wildlife coexistence is a different perspective about conflict, Gao says. “Conflict,” he has found, “is part of coexistence.”

    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.

    Cecilia Rogers in a forest glen

    Mapping Panama’s Sustainable Farmlands

    A researcher for the Environmental Leadership & Training Initiative, Cecilia Rogers ’22 MFS is mapping the success of ELTI’s Panama program that helps cattle ranchers incorporate sustainable practices, such as the use of forested pastureland, into their land management.

    Working with fellow students, she found that the amount of sustainably managed farmland had significantly increased from 4% in 2011 to 66% in 2020.

    AJ HUdson in a tropical landscape

    Climate Justice for Cities

    As a public school teacher in New York City watching socially marginalized Black and Latinx students struggle with inequalities in education and health issues from an emerging lead poisoning crisis, A.J. Hudson ’19 MESc was moved to take action. He helped found a public high school and led neighborhood workshops on climate justice and political action efforts.

    He also helped organize coalitions to pass New York’s Climate Leadership and Community Protection Act and helped plan the 2019  Youth Climate Summit, the nation’s largest gathering of young people of color passionate about climate change.

    Irene Shi sitting in front of blue-green lake in the mountains

    Preserving China’s Biodiversity

    As the executive director of the Shan Shui Conservation Center in China, Irene Xiangying Shi ’13 MESC is helping conservation efforts in the Tibetan Plateau and southern regions. The Center focuses its work on urban ecosystems and endangered species, such as giant pandas and snow leopards. 

    “If we have the right incentives,” she says, “people will conserve nature in the best way." Her efforts have helped build a biodiversity conservation alliance, an information sharing platform on biodiversity, and long-term funding mechanisms to continue work on these issues.

    Rich Guldin leaning against a tree in the forest

    Tracking Forest Inventory

    Richard Guldin ’76 MFS, ’79 PhD has helped reinvent the U.S. Forest Service’s Forest Inventory and Analysis (FIA) program by integrating new sampling designs, field procedures, and innovative software to create an annual inventory that has become a global model. His work earned him the Society of American Foresters’ Sir William Schlich Award.

    Program Timeline

    Year One — Fall Semester

    • Introduction to the MESc and MFS Degrees (ENV 555), is mandatory and a requirement for all incoming MESc/MFS students in their first Fall semester. This course will meet the first 6 weeks of the Fall semester and students will be pre-registered.
    • Take the research methods class appropriate for your area of research.
    • Meet with your advisor to discuss your research plans, publication goals, and any ambitions for further study.
    • Complete a draft of your research proposal by the end of the term.

    First Year — Spring Semester

    • Enroll in courses that will provide new knowledge and skills to augment your proposed research plan, this might include data analysis courses, skills based courses, or courses that can build your understanding of the literature in your field of research.
    • Craft and submit funding applications.
    • Continue to refine your research proposal in consultation with your advisor.
    • Discuss the possible development of a committee with your advisor, and if you choose to have one, identify possible committee members and begin reaching out to them to gain their agreement to serve in this role.
    • Pursue human subjects research approvals or animal care protocol approvals (and associated training) if needed, and consult any collaborators to ensure you understand any applicable regulatory structures with their institutions. Note: This should be initiated in January of the spring term.
    • If you are doing international work, research which visas and import, export, or research permits you may need as well as other various permissions. Understand and plan for the timelines needed to secure these documents.  
    • Attend the field research safety session if you are doing field research.
    • Register your summer travel with Yale, if you will be traveling off campus.
    • Complete the MESc and MFS Thesis Proposal form by April 1st
    • If you are traveling to conduct your research, be sure to meet with your advisor prior to departure to discuss your research plan and ensure a common vision.


    Conduct independent research, keeping excellent notes and ensuring that you back up your data.

    Second Year — Fall Semester

    • Meet with your advisor early in the term to discuss your summer research, and plan for the coming year.
    • Consider additional data analysis courses to inform your work.
    • Build a timeline for data analysis and writing; Gantt charts are one common planning tool that might be of use.
    • Plan to complete a full draft by the end of the term.

    Second Year — Spring Semester

    • As you refine your full draft, seek feedback from your advisor and
      visit the Graduate Writing Lab  for additional writing support.
    • Produce a nearly final draft before the YSE Research Day in April so that you can provide a complete and high impact presentation.  Note: An oral presentation at YSE Research Day is a graduation requirement for MESc and MFS students.
    • Submit your final thesis to your advisor, committee members (if relevant), and the YSE Dean’s Office by the final day of spring semester classes; be sure to name the file First Name_Last Name_Degree Type_Class Year


    The MESc/MFS is a 48-credit program, with formal coursework comprising at least 24 credits. Decisions on the timing for completion of the coursework credits are made by the student and research advisor. Courses may be distributed evenly over two years, or a greater course load may be carried in Year 1 to accommodate research-related travel and fieldwork in Year 2.

    Introduction to the MESc and MFS Degrees (ENV 555), is mandatory and a requirement for all incoming MESc/MFS students in their first Fall semester. This course will meet the first 6 weeks of the Fall semester and students will be pre-registered. This course will be graded credit/fail. The goal of this class is to set expectations and discuss general strategies for a successful MESc/MFS experience.

    MESc/MFS students are required to complete Qualitative Inquiry for the Human Sciences (ENV 551) or Natural Science Research Methods (ENV 550) in their first semester. Another research methods course may be substituted for ENV 551 or  ENV 550 when appropriate and subject to approval of the research advisor.

    Students should work with their advisors to select their remaining courses that will support the design, execution, and communication of their Master’s research and that are consistent with their career goals. These courses may be drawn from YSE, as well as from other departments or schools within Yale. 

    YSE Course Listings


    1. Thesis Research Credits

    MESc/MFS students must also complete at least 12 credits of Thesis Research. Students may register for a maximum of six credits per semester of Thesis Research during their first year and up to 12 credits per semester in their second year, provided the 24-credit coursework requirement is satisfied. Thesis Research is graded as Credit/Fail and culminates with the Master’s Thesis.

    2. The Master’s Thesis

    The Master’s Thesis should be a coherent piece of scholarship in the form of one or more major papers suitable for publication in a peer-reviewed journal or as a chapter in an edited book. A Master’s Thesis typically includes original data or an original analysis of published data and leads to novel interpretations and new findings. The thesis should draw from research that begins and is carefully planned in Year 1. The research should be sustained through the summer and serve as a focus of student effort in Year 2.

    3. Thesis Requirements

    The thesis requirements consist of a research proposal and the thesis itself. The purpose of the proposal is to demonstrate that the study has scientific merit, the research plan is tractable, the methods are appropriate, and the results will likely represent a meaningful contribution to the scientific community. The proposal serves as a formal mechanism by which students can gain feedback on their progress, learn of potential pitfalls and problems, and receive counsel on requisite modifications to the research plan. The proposal should be submitted for committee review no later than 30 September in Year 2.  In some cases, advisors may require students intending to begin research over the Summer between Years 1 and 2 to have a completed proposal by the end of the second term in Year 1.

    The thesis should be completed by the end of Year 2. Meeting this timeframe relies on the conscientiousness and vigilance of the students and their advisors. As an illustration, we provide scheduling guidelines for Year-2 tasks that would lead to on-time completion of the thesis and graduation in two years:

    • Late March: student submits completed first draft of thesis to committee chair
    • First week of April: committee chair returns comments for revisions to student
    • Third Week of April: student submits revised draft to thesis committee
    • Fourth week of April: thesis committee returns assessment and recommends approval in present form or further revisions
    • Last Day of Spring Semester Classes: student completes revisions (if necessary) and submits final version of thesis to the committee for approval.

    Research Presentation to the Yale Community

    An important part of conducting research is communicating research findings to the wider scientific community. Therefore, as part of their degree requirement, second-year MESc/MFS students must present the findings of their research at the annual YSE Research Colloquium, which is held in April. Students will receive a grade of Satisfactory Completion for this effort.

    Contact Master’s Admissions

    Introduce yourself to the YSE master’s admissions team.

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    Learning Communities composite illustration

    Learning Communities

    YSE's Learning Communities were created to offer robust interdisciplinary experiences and networks. Students may engage with as many learning communities as they choose, regardless of their degree program or specialization.