Earth and Environmental Sciences (Ph.D.)

The graduate program in Natural Resources and Earth Systems Science (NRESS) is an interdepartmental program offering the Ph.D. degree for interdisciplinary work in areas related to the understanding and management of the environment in the broadest context. Areas of study include, but are not limited to, ecosystem science, biogeochemical cycling, geochemical systems, atmospheric science, environmental philosophy, forestry, geologic science, hydrology, marine science, oceanography, social science, environmental policy and ethics, environmental education, and multidisciplinary natural resources management.

Earth and Environmental Sciences (EES)

The NRESS Ph.D. in Earth and Environmental Sciences (EES) focuses on problems dealing with the physical, chemical, and/or biological processes that affect earth and environmental systems. Students receiving the Ph.D. degree in EES will typically have a bachelor's and/or master’s degree in biology, ecology, environmental science, geology, hydrology, or microbiology.

Degree Requirements

The requirements of the doctoral program are flexible to accommodate the diverse interests and needs of students. All students in the NRESS program must meet the requirements listed below.

Committees and Coursework

The Ph.D. guidance and dissertation committees must consist of at least five members. The chair must be a member of the NRESS faculty. Three of the five members (including the chair) must be NRESS faculty, and committee members must be from more than one academic department. Students are strongly encouraged to include at least one off-campus member. Off-campus committee members must hold a doctoral (or terminal) degree and be approved by the student's adviser, the NRESS Program, and the Graduate School dean. Students should select the guidance committee in a timely manner, within one year for full-time students and two years for part-time students.

Core Area Course Requirements

All students will take one course in each of four core areas while enrolled in the program: natural sciences, ethics/policy/law, methods, and seminar. Students are also required to take NRES 997 Interdisciplinary Research in Natural Resources and Earth and Environmental Sciences, preferably within the first year of enrollment. Any course used to satisfy the natural sciences, ethics/policy/law, and methods core areas must be a classroom course of at least 3 credits. The seminar course must be interactive and must be at least 1 credit. Independent study courses may not be used to satisfy core requirements. Students must complete a Preliminary Coursework Approval Form, which lists the student's planned coursework, within one year for full-time students and two years for part-time students. A Final Course Approval Form, with signatures from the adviser, committee members, and the NRESS program chair is submitted once the coursework is completed.

Students Entering the Program without a Master's Degree

Students entering the program without a master's degree are expected to complete a minimum of 36 credit hours. There is not a specific credit requirement beyond the required four core courses and NRES 997 for students who have completed a M.S. or M.A. degree in a related field. Students enter the NRESS program with diverse backgrounds and preparation in their desired area of study. Therefore, final credit requirements are determined by the guidance committee and may include additional coursework necessary to enhance the student's selected field of study and/or correct any deficiencies in the student's previous program. Students may apply a maximum of 12 credits of independent study and/or seminar courses to their total course requirement.

Transfer Credits

Graduate-level courses taken prior to admission may be transferred into the program and applied to the total only if they were not taken while matriculated in another degree program, as per Graduate School policy. These courses may not be used to meet the core course requirements. Transfer of credits must be approved by the adviser, the guidance committee, and the Graduate School.

Language Proficiency

Language proficiency may be required at the discretion of the student's adviser/committee. If required, a student will need to show proficiency in one foreign language or one computer language.


Each student is required to pass three examinations, each of which has both a written and oral component. Additional preliminary examinations may be administered before the three required exams as the committee deems necessary. Performance on such an exam will determine areas where the student needs additional coursework or could result in the student's removal from the program.

Comprehensive exam (sometimes referred to as the qualifying exam): The student must prepare an extensive written answer to one question from each committee member that covers the basic concepts and factual material deemed essential for the student’s program. Three weeks are allowed for completion of the exam during which time students are expected to work solely on their answers.  Answers are expected to be anywhere from 10 – 20 pages per question with extensive literature citations. Completed written answers are submitted to the adviser who then distributes copies to the other committee members for review.  Approximately 1 – 2 weeks are allowed for the committee to read the answers, after which time the student gives an oral presentation to the committee. Following the presentation, committee members will ask for clarification of the student’s answers, if necessary.  The committee may require a student to repeat part, or all, of the comprehensive exam if the student’s performance is deemed unsatisfactory. This exam should be taken within three years of initiation of graduate study in the program.

Proposal exam: The student must present to the committee a written proposal on the dissertation research topic. Once the proposal is written, the student will complete a public oral presentation of the proposed research, followed by an oral examination by the committee.

Final exam: The student must complete a written Ph.D. dissertation prior to the final exam. Once written, the student is required to complete an oral defense of the dissertation, which will include both a public presentation and oral examination by the committee.

A student may be required to take additional courses following either the comprehensive or proposal exam, or may be removed from the program following failure of any of the required exams. Students are advanced to candidacy after successfully completing the comprehensive exam, proposal exam, and all coursework required by the guidance committee as summarized on the Coursework Approval Form.

The Earth and Environmental Sciences (EES) PhD degree within the Natural Resources and Earth Systems Science PhD Program trains scientists whose research addresses fundamental and applied questions dealing with the physical, chemical, and/or biological processes that affect earth and environmental systems at local, regional, national, and global scales. Through interdisciplinary coursework and doctoral research, we train researchers who can independently pursue the process of science and scholarship, and effectively apply their research to both solve basic questions in earth and environmental science and apply their work to issues of relevance to society and the environment, especially in this era of global change. learning outcomes:

  • Critically review and cogently synthesize relevant literature, and identify need for new research.
  • Draw on previously published work to independently design and execute new experiments or field manipulations or develop models with a high degree of sophistication. The design and execution of an experiment or the building of a model should demonstrate an understanding of good laboratory or field or modeling practices.
  • Structure a coherent and convincing scientific or policy argument.
  • Lead the writing of manuscripts describing their research and its impacts that are suitable for publication in peer-reviewed scientific journals or appropriate professional outlets for their particular sub-discipline, and be able to describe their research in presentations at national meetings of major relevant scientific societies, and at national and international symposia hosted by other professional organizations. The general expectation is that the final dissertation will include three first-authored publications submitted to or accepted in a peer-reviewed journal, or ready for submission.
  • Articulate how their research relates to a broader context outside of academia, and how their expertise will be applicable in the execution of complex research problems.