Steven C. Wofsy

Steven C. Wofsy

  • Abbott Lawrence Rotch Professor of Atmospheric and Environmental Science; Associate of Harvard Forest
  • Faculty Associate, Harvard University Center for the Environment


The composition of the earth's atmosphere has been altered dramatically by emissions of industrial gases and pollutants, combustion of fossil fuel and biomass, and cultivation of agricultural land. Understanding the associated impacts on climate and on human and environmental health is a challenging problem with enormous societal implications. To manage wisely the world's resources, we need quantitative information defining sources, sinks, and transformations of atmospheric gases and aerosols, and we need deeper knowledge of how the atmosphere works as a chemical and physical system.

Professor Wofsy and associates study the two-way exchange of gases between natural ecosystems and the atmosphere, the emissions, transformations and deposition of atmospheric pollutants, the processes that transport pollutants in the atmosphere, and depletion of stratospheric ozone. The focus is on long-term measurements to help understand processes affecting atmospheric composition on time scales relevant to climate change, and airborne observations to define rates of pollutant transport and sources or sinks of key gases (CO2, CO, nitrogen oxides) on continental and global scales.

We have programs studying the net carbon balance of major ecosystems, where we measure carbon exchange with the atmosphere and simultaneous ecological changes. Hourly data are carefully aggregated to seasons, years, or a decade. We also measure deposition of pollutants such as ozone or NOx. We focus on phenomena at the longer time scales, not apparent in short-term data, that represent the primary forcing for sequestration of fossil fuel CO2 by forest ecosystems or that have long-term effects on forest health and growth. These observations are carried out continuously at remote sites in sub-boreal, temperate, and tropical forests, using advanced instrumentation developed in our laboratory for these measurements. We also measure CO2 and CO in the stratosphere and on in the lower atmosphere. The measurements in the stratosphere and upper troposphere focus on understanding residence times and transport of pollutants, using an inert tracer with a rich source spectrum (CO2). The focus of the tropospheric measurements is to develop methods for determining regional- and continental-scale net sources from detailed airborne, and eventually spaceborne, observations. For additional information please see the Forest and Stratospheric Measurements page.

Contact Information

Nickname: Steve
Office:453 Geological Museum
Office Phone:(617) 495-4566
Office Fax(617) 495-4551
Lab Name:Forest and Atmospheric Measurements
Lab Location:453 Geological Museum
Assistant:Brenda L Mathieu
Assistant Office:Pierce Hall 109
Assistant Phone:617/496-5745
Research Mgr: Tetyana Donnelli

Primary Teaching Area

Positions & Employment

Harvard School of Engineering and Applied Sciences/Department of Earth and Planetary Sciences, Harvard University

  • February, 1997-Present: Abbott Lawrence Rotch Professor of Atmospheric and Environmental

Department of Earth and Planetary Sciences, Harvard University

  • 2006-Present: Director of Undergraduate Studies, EPS concentration

Faculty of Arts and Sciences, Harvard University

  • 2003-2004; 2005-2006: Associate Dean

California Institute of Technology

  • November, 2004: Moore Distinguished Scholar

Harvard Division of Applied Sciences and Department of Earth and Planetary Sciences, Harvard University

  • February, 1995-February 1997: Gordon McKay Professor of Atmospheric and Environmental

Harvard Division of Engineering and Applied Physics

  • July 1982-February 1995: Senior Research Fellow

Harvard Forest, Harvard University

  • July 1990-Present: Associate of the Harvard Forest, Harvard University

Harvard Division of Engineering and Applied Physics

  • July 1977-June 1982: Associate Professor of Atmospheric Chemistry

Harvard Division of Engineering and Applied Physics

  • September 1973 to June 1977: Lecturer on Atmospheric Chemistry and Research Fellow in the
    Center for Earth and Planetary Physics

Other Experience & Professional Membership

  • Fellow of the American Association for the Advancement of Science
  • Fellow of the American Geophysical Union


  • James B. MacIlwane Award, American Geophysical Union, 1982
  • Ledlie Prize for experimental and theoretical investigation of ozone depletion in the stratosphere, Harvard University
  • Distinguished Public Service Medal, National Aeronautics and Space Administration, June 2001