Dr. John R. Christy

"...fundamentally advancing our ability to monitor climate."



Professor and Director of ESSC

Office: NSSTC 4040
Phone: 256.961.7763
Fax: 256.961.7751
Email: christy@nsstc.uah.edu

Research Interests

  • Global Climate Change
  • Satellite Sensing of Global Climate
  • Paleoclimate 


Dr. John R. Christy is the Distinguished Professor of Atmospheric Science and Director of the Earth System Science Center at the University of Alabama in Huntsville where he began studying global climate issues in 1987. Since November 2000 he has been Alabama's State Climatologist. In 1989 Dr. Roy W. Spencer (then a NASA/Marshall scientist and now a Principle Research Scientist at UAH) and Christy developed a global temperature data set from microwave data observed from satellites beginning in 1979. For this achievement, the Spencer-Christy team was awarded NASA's Medal for Exceptional Scientific Achievement in 1991. In 1996, they were selected to receive a Special Award by the American Meteorological Society "for developing a global, precise record of earth's temperature from operational polar-orbiting satellites, fundamentally advancing our ability to monitor climate." In January 2002 Christy was inducted as a Fellow of the American Meteorological Society.

Dr. Christy has served as a Contributor (1992, 1994, 1996 and 2007) and Lead Author (2001) for the U.N. reports by the Intergovernmental Panel on Climate Change in which the satellite temperatures were included as a high-quality data set for studying global climate change. He has served on five National Research Council panels or committees and has performed research funded by NASA, NOAA, DOE, DOT and the State of Alabama and has published many articles including studies appearing in Science, Nature, Journal of Climate and The Journal of Geophysical Research. Dr. Christy has provided testimony to several congressional committees.

Dr. Christy received the M.S. and Ph.D. degrees in Atmospheric Sciences from the University of Illinois (1984, 1987). Prior to this career path he had graduated from the California State University in Fresno (B.A. Mathematics, 1973, Distinguished Alumnus 2007) and taught Physics and Chemistry as a missionary teacher in Nyeri, Kenya for two years. After earning a Master of Divinity degree from Golden Gate Baptist Seminary (1978) he served four years as a bivocational mission-pastor in Vermillion, South Dakota where he also taught college math. He was featured in the February 2001 issue of Discover magazine and in a National Public Radio profile in 2004 in which his diverse background was highlighted.

Dr. Christy has been active in local educational groups. At Grissom High School he served as chairman of the Facilities committee, helping to secure the new Science wing and Gymnasium and was President of its PTSA, Alabama's largest, in 1997-98. He also served on the Huntsville City Schools Strategic Planning Committee and its Finance sub-panel. He is a member of the Huntsville City Surface Water Management Committee.

Dr. Christy is married to the former Babs Joslin, a fellow missionary whom he met in Kenya. They have two married children, Mrs. Alison Fields, an Applied Math graduate of Auburn University and Brian, a Physics/Math graduate of Auburn and now a graduate student at the University of Maryland. Garet and Alison Fields are parents of three of their grandchildren and Brian and Kristen Christy of their fourth. Dr. Christy's favorite hobby is gold panning which he developed as a teenager in California, and he also runs, completing races from 2 to 31.1 miles over rugged terrain.

Why Atmospheric Science?

As a kid growing up in the San Joaquin Valley of California, I was simply fascinated with the way the weather varied between the valley and the mountainous Sierras. I began to wonder about why one year was wet and another dry, so I built my first climate datasets when I was 12, using a mechanical pencil, graph paper, and long-division (no calculators back then.) I've been a climate nerd ever since.


  • PhD University of Illinois, 1987, Atmospheric Science
  • M.S. University of Illinois, 1984, Atmospheric Science
  • M.Div. Golden Gate Baptist Theological Seminary, 1978
  • B.A. California State University, Fresno, 1973, Mathematics


  • 2008 Distinguished Professor of The University of Alabama in Huntsville
  • 2007 Distinguished Alumnus, California State University, Fresno
  • Panel Member, American Geophysical Union, Official Statement on Climate Change 2003.
  • Fellow, American Meteorological Society 2002
  • 1996 Special Award, American Meteorological Society "for developing a global, precise record of earth's temperature from operational polar-orbiting satellites, fundamentally advancing our ability to monitor climate."
  • 1991 Medal for Exceptional Scientific Achievement, NASA Headquarters
  • "Op-Ed, Atlanta Journal Constitution, 11 March 2001" (word document)

hearingsCongressional Hearings

  • House Science, Space and Technology Committee, 31 March 2011 (PDF)
  • House Subcommittee on Energy and Power, 8 March 2011 (PDF)
  • House Ways and Means Committee, 25 Feb 2009 (PDF)
  • Senate Commerce, Science and Transportation Committee, 14 Nov 2007 (PDF)
  • House Subcommittee on Energy and Air Quality, 7 March 2007 (PDF)
  • House Committee on Government Reform, 20 July 2006 (PDF)
  • House Subcommittee on Oversight, Energy and Commerce, 27 July 2006 (PDF)
  • Congressional Record 23 May 2003 JRChristy, African Experience (PDF)
  • House Committee on Resources 13 May, 2003
    ** Verbal Remarks
  • Senate Committee on the Environment and Public Works 2 May, 2001
    ** Verbal Remarks
    ** Written Remarks
    ** PowerPoint Presentation
  • Senate Committee on Commerce, Science and Transportation 17 May 2000
  • House Committee on Small Business, 29 July 1998
  • Senate Committee on the Environment and Public Works, 10 July 1997
  • House Committee on Science, 9 March 1996


  • John R. Christy, February, 2010. IPCC: cherish it, tweak it or scrap it?Nature, Vol 463, p. 732. (pdf)
  • John R. Christy and Justin J. Hnilo, 2010. CHANGES IN SNOWFALL IN THE SOUTHERN SIERRA NEVADA OF CALIFORNIA SINCE 1916. Reprinted from ENERGY & ENVIRONMENT VOLUME 21 No. 3 2010. (pdf)
  • John R. Christy 1,*, Benjamin Herman 2, Roger Pielke, Sr. 3, Philip Klotzbach 4, Richard T. McNider 1, Justin J. Hnilo 1, Roy W. Spencer 1, Thomas Chase 3 and David Douglass 5, 2010. What Do Observational Datasets Say about Modeled Tropospheric Temperature Trends since 1979? Remote Sensing ISSN 2072-429. (pdf)
  • Douglass, D.H., J.R. Christy, 2009: Limits on CO2 climate forcing from recent temperature data of Earth. Energy & Environment, 20, 178-189 (Invited paper, reviewed by Editor.) (pdf)
  • JOHN R. CHRISTY AND WILLIAM B. NORRIS, 2008: Discontinuity Issues with Radiosonde and Satellite Temperatures in the Australian Region 1979–2006. (Manuscript received 13 February 2008, in final form 26 August 2008) (pdf)
  • JOHN R. CHRISTY, WILLIAM B. NORRIS, AND RICHARD T. MCNIDER, 2008. Surface Temperature Variations in East Africa and Possible Causes. (Manuscript received 16 July 2008, in final form 1 December 2008) (pdf)
  • JOHN R. CHRISTY and MASAMI SAKAMOTO, 2008. The Influences of TOVS Radiance Assimilation on Temperature and Moisture Tendencies in JRA-25 and ERA-40. Manuscript received 26 June 2008, in final form 18 December 2008). (pdf)
  • Douglass, D.H., J.R. Christy, B.D. Pearson and S.F. Singer, 2007: A comparison of tropical temperature trends with model predictions. International J. Climatology, DOI: 10.1002/joc.1651. (pdf)
  • Christy, J.R. and W.B. Norris, 2006: Satellite and VIZ-Radiosonde intercomparisons for diagnosis on non-climatic influences. J. Atmos. Oc. Tech., 23, 1181 – 1194.
  • Spencer, R.W., J.R. Christy, W.D. Braswell and W.B. Norris, 2006: Estimation of tropospheric temperature trends from MSU channels 2 and 4. J. Atmos. Oc. Tech., 23, 417-423.
  • Christy, J.R., 2006: The ever-changing climate system. Cumberland Law Review, 36 No. 3, 493-504,
  • Christy, J.R., W.B. Norris, K. Redmond and K. Gallo, 2006: Methodology and results of calculating central California surface temperature trends: Evidence of human-induced climate change? J. Climate, 19, 548-563.
  • Christy, J.R. and R.W.Spencer, 2005: Correcting temperature data sets. Science, 310, 972.
  • Christy, J.R. and W.B. Norris, 2004: What may we conclude about tropospheric temperature trends? Geophys. Res. Lett., 31, No. 6, L0621.
  • Christy, J.R. and R.W. Spencer, 2003: Reliability of satellite data sets. Science, 301, 1046-1047.
  • Christy, J.R., 2003: Climate Research - Response to "Wanted Scientific Leadership on Climate" by Pielke, Jr. and Sarewitz. Issues in Science and Technology. Spring 2003, 9-10.
  • Christy, J.R., R.W. Spencer, W.B. Norris, W.D. Braswell and D.E. Parker, 2003: Error estimates of Version 5.0 of MSU/AMSU bulk atmospheric temperatures. J. Atmos. Oceanic Tech. 20, 613-629.
  • Christy, J.R., 2002: When was the hottest summer? A State Climatologist struggles for an answer. Bull. Amer. Met. Soc. 83, 723-734.
  • Christy, J.R., D.E. Parker, S.J. Brown, I. Macadam, M. Stendel and W.B. Norris, 2001: Differential trends in tropical sea surface and atmospheric temperatures. Geophys. Res. Lett. 28, 183-186.
  • Winter, A., O. Tadamichi, H. Ishioroshi, T. Watanabe and J. R. Christy, 2000: A two-to-three degree cooling of Caribbean sea surface temperatures during the Little Ice Age. Geophys. Res. Lett., 27, 3365-3368.
  • Hurrell, J., S.J. Brown, K.E. Trenberth and J.R. Christy, 2000: Comparison of tropospheric temperatures from radiosondes and satellites: 1979-1998. Bull. Amer. Met. Soc., 81, 2165-2177.
  • Gaffen, D.J., B.D. Santer, J.S. Boyle, J.R. Christy, N.E. Graham, R.J. Ross, 2000: Multidecadal changes in the vertical structure of the tropical troposphere. Science, 287, 1242-1245.
  • Christy, J.R., 2000: Global Climate Change: Scientific and Social Impacts. Bridges. 7, 39-57.
  • Christy, J.R., R.W. Spencer, and W.D. Braswell, 2000: MSU Tropospheric temperatures: Data set construction and radiosonde comparisons. J. Atmos. Oceanic Tech. 17,1153-1170.
  • Stendel, M., J.R. Christy and L. Bengtsson, 2000: Assessing levels of uncertainty in recent temperature time series. Climate Dynamics, 16(8), 587-601.
  • Christy, J.R., R.W. Spencer, and E. Lobl, 1998 Analysis of the merging procedure for the MSU daily temperature time series. J. Climate, 11, 2016-2041.
  • Christy, J.R., R.W. Spencer, and D. Braswell, 1997 How accurate are satellite 'thermometers'?, Nature, 389, 342-3.
  • Christy, J.R. , 1995 Temperature above the surface layer. Climatic Change , 30, 455-474.
  • Christy, J.R., R.W. Spencer and R.T. McNider, 1995 Reducing noise in the MSU daily lower tropospheric global temperature data set. J Climate , 8, 888-896.
  • Christy, J.R. and J. Goodridge, 1995 Precision global temperatures from satellites and urban warming effects of non-satellite data. Atmos. Env. 29, 1957-1961.
  • Christy, J.R. and R. T. McNider, 1994 Satellite greenhouse signal. Nature, 367, 325.
  • Christy, J.R. and S.J. Drouilhet, 1994 Variability in daily, zonal mean lower-stratospheric temperatures. J. Climate, 7, 106-120.

globeNational Research Council

  • National Research Council: Committee on Surface Temperature Reconstructions for the last 2,000 years. 2006
  • Space Studies Board, Committee on Environmental Satellite Data Utilization 2003-04
  • Panel on NASA Science Review 2000
  • Letter Report to NESDIS (chairman) 2000
  • Space Studies Board, Committee on Earth Studies 1998-2001
  • Panel on Atmospheric Temperature 1999

International Panel on Climate Change

  • 2007 Contributor
  • 2001 Lead Author
  • 1996 Key Contributor
  • 1994 Contributor
  • 1992 Contributor