what is earth system science?

Earth System Science (ESS) is a highly interdisciplinary field of research that studies how the atmosphere, land, oceans, cryosphere, and life interact as a system. A primary focus of our department is to understand how human activities contribute to climate and environmental  change and how to preserve the habitability of our planet.

In particular, our research community combines direct observations from the field or from satellites, laboratory experiments, data analysis, and numerical modeling to address issues including land degradation, air pollution, extreme weather events, loss of biodiversity or sea level rise.

what makes us unique?

Our ESS department is composed of diverse and passionate scientists, with expertise in different disciplines, who work together to understand and solve the climate crisis.

We are a relatively small department where you have the opportunity to directly interact with faculty, researchers, and students, and become an active member of our research groups.

Small class sizes and a large number of electives allow you to build a strong peer-network and tailor your course work to your personal interests, to pursue our honors program or to double major. Hands-on training provides you with valuable skills (e.g., GIS, field methods, data analysis, programing) for wherever your career may take you.

We encourage you to further enrich your college experience and our ESS department: Participate or organize ESS club events (e.g., the annual “Industry Night” employment fair),  build community and gain teaching experience as a peer-mentor or learning assistant, explore the world with UCI’s study abroad program, or gain work experience as an intern at the white house, congress or advocacy groups (e.g., UCI’s CEB, UC’s DC programs).


We offer 2 majors, 1 minor, and 1 PhD program.

  • In our BS program you will learn the science of climate change. It prepares you for careers in science, research, or technical fields.
  • Our BA program is in partnership with the School of Social Ecology, and you will learn about both the science and policy aspects of climate change and sustainability. The program prepares you for a career in government, non-profit or private industry.
  • Our Minor in Earth and Atmospheric Sciences offers students in the natural sciences and engineering a path to explore interdisciplinary problems and broaden their studies.
  • Our PhD program is aimed at people who want a career in research and academia.
Bachelor of Science in Earth System Science

Learn the science behind major environmental issues like climate change, ocean acidification, land degradation, and air quality.  Develop the STEM, laboratory, and computational skills needed for a career in environmental science.

Bachelor of Arts in Environmental Science and Policy

Study environmental impacts on society, and how human actions and policy can enhance global sustainability. Prepare for a career at the science/policy interface in government, nonprofit organizations, and private industry.

Ph.D. in Earth System Science

Do research with world experts at the forefront of global environmental change. Develop the skills to advance our understanding of Earth’s atmosphere, oceans, and land systems and enable solutions to major environmental issues.

where will you make your mark?


  • Environmental consulting
  • Spatial data analyst

State/Federal Agency

  • Environmental Protection Agency
  • Air quality
  • Water management


  • National laboratories
  • Universities

Policy, regulations, NGOs

  • Economics
  • Public policy
  • Activism
  • Environemntal advocacy group


Contact Us

Bao Vu
Student Affairs Manager
(949) 824-1604
Professor Alex Guenther
Vice Chair, Undergraduate Studies
(949) 824-7320

The Department of Earth System Science acknowledges our presence on the ancestral and unceded territory of the Acjachemen and Tongva peoples, who still hold strong cultural, spiritual and physical ties to this region.