John Christy

John Christy

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John R. Christy is a climate scientist at the University of Alabama in Huntsville
University of Alabama in Huntsville
The University of Alabama in Huntsville is a state-supported, public, coeducational research university, located in Huntsville, Alabama, United States, is accredited by the Southern Association of Colleges and Schools to award baccalaureate, master's and doctoral degrees, and is organized in five...

 (UAH) whose chief interests are satellite
Satellite
In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....

 remote sensing
Remote sensing
Remote sensing is the acquisition of information about an object or phenomenon, without making physical contact with the object. In modern usage, the term generally refers to the use of aerial sensor technologies to detect and classify objects on Earth by means of propagated signals Remote sensing...

 of global climate and global climate change. He is best known, jointly with Roy Spencer, for the first successful development of a satellite temperature record.

Early life and education


A native of Fresno, California
Fresno, California
Fresno is a city in central California, United States, the county seat of Fresno County. As of the 2010 census, the city's population was 510,365, making it the fifth largest city in California, the largest inland city in California, and the 34th largest in the nation...

, Christy received a B.A. in Mathematics (1973) from the California State University, Fresno
California State University, Fresno
California State University, Fresno, often referred to as Fresno State University and synonymously known in athletics as Fresno State , is one of the leading campuses of the California State University system, located at the northeast edge of Fresno, California, USA.The campus sits at the foot of...

, and an M.S. and Ph.D. in Atmospheric Sciences
Atmospheric sciences
Atmospheric sciences is an umbrella term for the study of the atmosphere, its processes, the effects other systems have on the atmosphere, and the effects of the atmosphere on these other systems. Meteorology includes atmospheric chemistry and atmospheric physics with a major focus on weather...

 (1984, 1987) from the University of Illinois. Prior to his scientific career, Christy taught physics and chemistry as a missionary teacher in Nyeri, Kenya (1973–75). After earning a Master of Divinity degree (1978) from Golden Gate Baptist Seminary he served four years as a bivocational mission-pastor in Vermillion, South Dakota, where he also taught college math.

He is a distinguished professor of atmospheric science, and director of the Earth System Science Center at the University of Alabama in Huntsville
University of Alabama in Huntsville
The University of Alabama in Huntsville is a state-supported, public, coeducational research university, located in Huntsville, Alabama, United States, is accredited by the Southern Association of Colleges and Schools to award baccalaureate, master's and doctoral degrees, and is organized in five...

. He was appointed Alabama
Alabama
Alabama is a state located in the southeastern region of the United States. It is bordered by Tennessee to the north, Georgia to the east, Florida and the Gulf of Mexico to the south, and Mississippi to the west. Alabama ranks 30th in total land area and ranks second in the size of its inland...

's state climatologist in 2000. For his development of a global temperature data set
Data set
A data set is a collection of data, usually presented in tabular form. Each column represents a particular variable. Each row corresponds to a given member of the data set in question. Its values for each of the variables, such as height and weight of an object or values of random numbers. Each...

 from satellites he was awarded NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...

's Medal for Exceptional Scientific Achievement, and the American Meteorological Society
American Meteorological Society
The American Meteorological Society promotes the development and dissemination of information and education on the atmospheric and related oceanic and hydrologic sciences and the advancement of their professional applications. Founded in 1919, the American Meteorological Society has a membership...

's "Special Award." In 2002, Christy was elected Fellow
Fellow
A fellow in the broadest sense is someone who is an equal or a comrade. The term fellow is also used to describe a person, particularly by those in the upper social classes. It is most often used in an academic context: a fellow is often part of an elite group of learned people who are awarded...

 of the American Meteorological Society
American Meteorological Society
The American Meteorological Society promotes the development and dissemination of information and education on the atmospheric and related oceanic and hydrologic sciences and the advancement of their professional applications. Founded in 1919, the American Meteorological Society has a membership...

.

Status and views


For many years Christy, along with Roy Spencer, has maintained an atmospheric temperature record derived from satellite microwave
Microwave
Microwaves, a subset of radio waves, have wavelengths ranging from as long as one meter to as short as one millimeter, or equivalently, with frequencies between 300 MHz and 300 GHz. This broad definition includes both UHF and EHF , and various sources use different boundaries...

 sounding unit measurements, commonly called the "UAH
University of Alabama in Huntsville
The University of Alabama in Huntsville is a state-supported, public, coeducational research university, located in Huntsville, Alabama, United States, is accredited by the Southern Association of Colleges and Schools to award baccalaureate, master's and doctoral degrees, and is organized in five...

" record – see satellite temperature record. This was once quite controversial
Global warming controversy
Global warming controversy refers to a variety of disputes, significantly more pronounced in the popular media than in the scientific literature, regarding the nature, causes, and consequences of global warming...

: From the beginning of the satellite record in late 1978 into 1998 it showed a net global cooling trend, although ground measurements and instruments carried aloft by balloons showed warming in many areas. Part of the cooling trend seen by the satellites can be attributed to several years of cooler than normal temperatures and cooling caused by the eruption of the Mount Pinatubo
Mount Pinatubo
Mount Pinatubo is an active stratovolcano located on the island of Luzon, near the tripoint of the Philippine provinces of Zambales, Tarlac, and Pampanga. It is located in the Tri-Cabusilan Mountain range separating the west coast of Luzon from the central plains, and is west of the dormant and...

 volcano. Part of the discrepancy between the surface and atmospheric trends was resolved over a period of several years as Christy, Spencer and others identified several factors, including orbital drift and decay, that caused a net cooling bias in the data collected by the satellite instruments. Since the data correction of August 1998 (and the major La Niña
La Niña
La Niña is a coupled ocean-atmosphere phenomenon that is the counterpart of El Niño as part of the broader El Niño-Southern Oscillation climate pattern. During a period of La Niña, the sea surface temperature across the equatorial Eastern Central Pacific Ocean will be lower than normal by 3–5 °C...

 Pacific Ocean warming event of the same year), data collected by satellite instruments has shown an average global warming trend in the atmosphere. From November 1978 through March 2011, Earth's atmosphere has warmed at an average rate of about 0.14 C per decade, according to the UAHuntsville satellite record.

Christy was a lead author of the 2001 report by the IPCC
Intergovernmental Panel on Climate Change
The Intergovernmental Panel on Climate Change is a scientific intergovernmental body which provides comprehensive assessments of current scientific, technical and socio-economic information worldwide about the risk of climate change caused by human activity, its potential environmental and...

 and the US CCSP
Climate Change Science Program
The Climate Change Science Program was the program responsible for coordinating and integrating research on global warming by U.S. government agencies from February 2002 to June 2009...

 report Temperature Trends in the Lower Atmosphere - Understanding and Reconciling Differences. Christy helped draft and signed the 2003 American Geophysical Union
American Geophysical Union
The American Geophysical Union is a nonprofit organization of geophysicists, consisting of over 50,000 members from over 135 countries. AGU's activities are focused on the organization and dissemination of scientific information in the interdisciplinary and international field of geophysics...

 statement on climate change.

Christy has also performed detailed reconstruction of surface temperature for Central California
Central California
Central California, sometimes referenced as Mid-State, is an area of California south of the San Francisco Bay Area and north of Southern California...

. He found that recorded temperature changes there were consistent with an altered surface environment caused by increased irrigation for agriculture, which changed "a high-albedo
Albedo
Albedo , or reflection coefficient, is the diffuse reflectivity or reflecting power of a surface. It is defined as the ratio of reflected radiation from the surface to incident radiation upon it...

 desert into a darker, moister, vegetated plain."

In a 2003 interview with National Public Radio about the 2003 American Geophysical Union
American Geophysical Union
The American Geophysical Union is a nonprofit organization of geophysicists, consisting of over 50,000 members from over 135 countries. AGU's activities are focused on the organization and dissemination of scientific information in the interdisciplinary and international field of geophysics...

 (AGU) statement, he said he is "a strong critic of scientists who make catastrophic predictions of huge increases in global temperatures and tremendous rises in sea levels". He added, though, that "it is scientifically inconceivable that after changing forests into cities, turning millions of acres into irrigated farmland, putting massive quantities of soot and dust into the air, and putting extra greenhouse gases into the air, that the natural course of climate has not changed in some way."

In a 2009 interview with Fortune Magazine about signing the 2003 American Geophysical Union
American Geophysical Union
The American Geophysical Union is a nonprofit organization of geophysicists, consisting of over 50,000 members from over 135 countries. AGU's activities are focused on the organization and dissemination of scientific information in the interdisciplinary and international field of geophysics...

 (AGU) statement, he said: "As far as the AGU, I thought that was a fine statement because it did not put forth a magnitude of the warming. We just said that human effects have a warming influence, and that's certainly true. There was nothing about disaster or catastrophe. In fact, I was very upset about the latest AGU statement [in 2007]. It was about alarmist as you can get."

In a 2007 editorial in the Wall Street Journal, he wrote: "I'm sure the majority (but not all) of my IPCC colleagues cringe when I say this, but I see neither the developing catastrophe nor the smoking gun proving that human activity is to blame for most of the warming we see."

In a 2007 ruling in a trial relating to automobile emission regulation in Vermont, U.S. District Court Chief Judge William K. Sessions mistakenly wrote, "Plaintiffs’ own expert, Dr. Christy, agrees with the IPCC’s assessment that in the light of new evidence and taking into account remaining uncertainties, most of the observed warming over the last fifty years is likely to have been due to the increase in GHG concentrations." What Christy said in his testimony was, "You know, it's a statement that has lots of qualifications in it, so it's hard to disagree with." and "You saw me pause a long time because — this was six years ago. And the question was about what I thought six years ago."

In 2009 written testimony to the U.S. House Ways and Means Committee, he wrote: "From my analysis, the actions being considered to 'stop global warming' will have an imperceptible impact on whatever the climate will do, while making energy more expensive, and thus have a negative impact on the economy as a whole. We have found that climate models and popular surface temperature data sets overstate the changes in the real atmosphere and that actual changes are not alarming."

Awards

  • 1991: NASA Exceptional Scientific Achievement Medal (with Roy Spencer).
  • 1996: AMS Special Award "for developing a global, precise record of Earth's temperature from operational polar-orbiting satellites, fundamentally advancing our ability to monitor climate" (with Roy Spencer).

See also


External links