Breadcrumb

Bio
My research interests are broad, but all revolve around the use of environmental stable isotope ratios.
I established and operated the Stable Isotope Laboratory for the analysis of stable isotope ratios of carbon, hydrogen, nitrogen, oxygen and sulfur. My specific areas of research include modeling the global carbon cycle using isotope ratios in atmospheric carbon dioxide and methane, development of techniques for measuring isotope ratios in atmospheric gases, reconstructions of paleo-environmental conditions using isotopes in ice cores, reconstructions of past environments from isotopes in organic materials, and tracing of ground water flow and recharge. I have been a member of several deep ice coring projects in Greenland (GISP2, NorthGRIP, and NEEM) and Antarctica (Siple Dome and Inland WAIS). I am also an affiliate of NOAA and work closely with the Carbon Cycle Group there.
Starting in the late 1980s, my ice core research has helped to show that large climate changes tend to occur in the natural system as abrupt and rapid shifts in mode probably driven by internal adjustments in the Earth climate system, rather than slow and gradual adjustments to changing external conditions, such as the amount of energy received from the sun. Shifts of more than 10˚C in mean temperature in less than a human lifetime are common in the paleoclimate record, and serve as a warning that adaptation to future climate changes may not be easy. My research in isotopes in the carbon cycle has also helped to show that land plants are capable of removing large amounts of carbon dioxide from the atmosphere, amounts that equal our input of CO2 from fossil fuel burning on short time scales. Such large changes in the uptake of CO2 by plants is a key piece in the puzzle we must solve to formulate workable policy on CO2 levels and climate change.
Education
- PhD: Columbia University, 1983
Awards
- Highly Cited Researcher (2016-2019), Web of Science Group, 2019
- Robert L. Stearns Award, CU Boulder Alumni Association, 2016
- Highly Cited Researcher, Thomson Reuters, 2014
- Fellow, American Association for the Advancement of Science, 2014
- Highly Cited Researcher, ISI, 2001
Research
Research interests: global scale climate and environmental dynamics; carbon dioxide concentrations and climate from stable hydrogen isotopes, peats and other organics; climate from deuterium excess and hydrogen isotopes in ice cores; isotopes in general circulation models; modern carbon cycle dynamics via isotopes of carbon dioxide and methane.
Publications
Recent publications
The climate signal in the stable isotopes of snow from Summit, Greenland: Results of comparisons with modern climate observations
Publication Date: 1997-11-30
Type: Journal Article
Detection and monitoring of stratigraphic markers and temperature trends at the Greenland Ice Sheet Project 2 using passive-microwave remote-sensing data
Shuman CA; Alley RB; Fahnestock MA; Fawcett PJ; Bindschadler RA; White JWC; Grootes PM; Anandakrishnan S; Stearns CR...
- Shuman CA
- Alley RB
- Fahnestock MA
- Fawcett PJ
- Bindschadler RA
- White JWC
- Grootes PM
- Anandakrishnan S
- Stearns CR
Publication Date: 1997-11-30
Type: Journal Article
The delta O-18 record along the Greenland Ice Core Project deep ice core and the problem of possible Eemian climatic instability
Johnsen SJ; Clausen HB; Dansgaard W; Gundestrup NS; Hammer CU; Andersen U; Andersen KK; Hvidberg CS; DahlJensen D; Steff...
- Johnsen SJ
- Clausen HB
- Dansgaard W
- Gundestrup NS
- Hammer CU
- Andersen U
- Andersen KK
- Hvidberg CS
- DahlJensen D
- Steffensen JP
Publication Date: 1997-11-30
Type: Journal Article
Validity of the temperature reconstruction from water isotopes in ice cores
Jouzel J; Alley RB; Cuffey KM; Dansgaard W; Grootes P; Hoffmann G; Johnsen SJ; Koster RD; Peel D; Shuman CA...
- Jouzel J
- Alley RB
- Cuffey KM
- Dansgaard W
- Grootes P
- Hoffmann G
- Johnsen SJ
- Koster RD
- Peel D
- Shuman CA
Publication Date: 1997-11-30
Type: Journal Article
The Holocene Younger Dryas transition recorded at Summit, Greenland
Taylor KC; Mayewski PA; Alley RB; Brook EJ; Gow AJ; Grootes PM; Meese DA; Saltzman ES; Severinghaus JP; Twickler MS...
- Taylor KC
- Mayewski PA
- Alley RB
- Brook EJ
- Gow AJ
- Grootes PM
- Meese DA
- Saltzman ES
- Severinghaus JP
- Twickler MS
Publication Date: 1997-10-31
Type: Journal Article
Reconstructing annual and seasonal climatic responses from volcanic events since AD 1270 as recorded in the deuterium signal from the Greenland Ice Sheet Project 2 ice core
Publication Date: 1997-08-27
Type: Journal Article
A three-dimensional synthesis study of delta O-18 in atmospheric CO2 .1. Surface fluxes
Ciais P; Denning AS; Tans PP; Berry JA; Randall DA; Collatz GJ; Sellers PJ; White JWC; Trolier M; Meijer HAJ...
- Ciais P
- Denning AS
- Tans PP
- Berry JA
- Randall DA
- Collatz GJ
- Sellers PJ
- White JWC
- Trolier M
- Meijer HAJ
Publication Date: 1997-03-20
Type: Journal Article
A three-dimensional synthesis study of delta O-18 in atmospheric CO2 .2. Simulations with the TM2 transport model
Ciais P; Tans PP; Denning AS; Francey RJ; Trolier M; Meijer HAJ; White JWC; Berry JA; Randall DA; Collatz GJ...
- Ciais P
- Tans PP
- Denning AS
- Francey RJ
- Trolier M
- Meijer HAJ
- White JWC
- Berry JA
- Randall DA
- Collatz GJ
Publication Date: 1997-03-20
Type: Journal Article
Monitoring the isotopic composition of atmospheric CO2: Measurements from the NOAA Global Air Sampling Network
Publication Date: 1996-11-20
Type: Journal Article
Oxygen isotope exchange between carbon dioxide and water following atmospheric sampling using glass flasks
Publication Date: 1996-06-20
Type: Journal Article
Leaf end plant water use efficiency of C-4 species grown at glacial to elevated CO2 concentrations
Publication Date: 1996-03-01
Type: Journal Article
Frequency analysis of an annually resolved, 700 year paleoclimatic record from the GISP2 ice core
Type: Chapter
THE ORIGIN OF PRESENT-DAY ANTARCTIC PRECIPITATION FROM SURFACE SNOW DEUTERIUM EXCESS DATA
Publication Date: 1995-09-20
Type: Journal Article
HIGH-RESOLUTION HOLOCENE AND LATE-GLACIAL ATMOSPHERIC CO2 RECORD - VARIABILITY TIED TO CHANGES IN THERMOHALINE CIRCULATION
Publication Date: 1995-09-01
Type: Journal Article
A LARGE NORTHERN-HEMISPHERE TERRESTRIAL CO2 SINK INDICATED BY THE C-13/C-12 RATIO OF ATMOSPHERIC CO2
Publication Date: 1995-08-25
Type: Journal Article
GREENLAND ICE CORE RECORDS AND RAPID CLIMATE-CHANGE
Publication Date: 1995-08-15
Type: Journal Article
TEMPERATURE AND ACCUMULATION AT THE GREENLAND SUMMIT - COMPARISON OF HIGH-RESOLUTION ISOTOPE PROFILES AND SATELLITE PASSIVE MICROWAVE BRIGHTNESS TEMPERATURE TRENDS
Publication Date: 1995-05-20
Type: Journal Article
PARTITIONING OF OCEAN AND LAND UPTAKE OF CO2 AS INFERRED BY DELTA-C-13 MEASUREMENTS FROM THE NOAA CLIMATE MONITORING AND DIAGNOSTICS LABORATORY GLOBAL AIR SAMPLING NETWORK
CIAIS P; TANS PP; WHITE JWC; TROLIER M; FRANCEY RJ; BERRY JA; RANDALL DR; SELLERS PJ; COLLATZ JG; SCHIMEL DS...
- CIAIS P
- TANS PP
- WHITE JWC
- TROLIER M
- FRANCEY RJ
- BERRY JA
- RANDALL DR
- SELLERS PJ
- COLLATZ JG
- SCHIMEL DS
Publication Date: 1995-03-20
Type: Journal Article
CHANGES IN OCEANIC AND TERRESTRIAL CARBON UPTAKE SINCE 1982
Publication Date: 1995-01-26
Type: Journal Article
Environmental studies at the University of Colorado
Type: Chapter
STABLE ISOTOPES OF OXYGEN AND HYDROGEN IN THE TRUCKEE RIVER PYRAMID LAKE SURFACE-WATER SYSTEM .3. SOURCE OF WATER-VAPOR OVERLYING PYRAMID LAKE
Publication Date: 1994-12-01
Type: Journal Article
CLIMATE IN THE PLEISTOCENE - REPLY
Publication Date: 1994-09-08
Type: Journal Article
A HIGH-RESOLUTION RECORD OF ATMOSPHERIC CO2 CONTENT FROM CARBON ISOTOPES IN PEAT
Publication Date: 1994-01-13
Type: Journal Article
MODELING AND INTERPRETING D/H RATIOS IN TREE-RINGS - A TEST-CASE OF WHITE-PINE IN THE NORTHEASTERN UNITED-STATES
Publication Date: 1994-01-01
Type: Journal Article
HOLOCENE TEMPERATURE VARIATIONS INFERRED FROM 6 ANTARCTIC ICE CORES
Publication Date: 1994-01-01
Type: Journal Article
Pages
Teaching
My teaching interests at the undergraduate level focus on human interactions with the environment, as well as general geosciences. I have a strong commitment to undergraduate education in this area, as I believe that an educated citizenry is important in ensuring that reasonable environmental policy is made and implemented. I teach and helped to develop a large lecture class, Introduction to Environmental Studies (ENVS 1000). This course covers the broad spectrum of environmental studies, from the social to the natural sciences. In addition, I developed and teach a large upper level undergraduate course, GEOL 3520, Environmental Issues. This course addresses our present and future energy sources, and how those energy sources affect the Earth’s systems, including climate and biogeochemistry. At the graduate level, I teach courses in my research specialty, stable isotope geochemistry and biogeochemistry. I have also taught the ENVS Honor’s course, and supervised the ENVS Internship Program. I have also been relatively successful in securing funding for education at CU. With a number of other faculty at CU, I have had grants funded by NASA (Earth System Science Education), as well as a multi-million dollar NSF-IGERT graduate training grant. This grant supported 13 graduate students per year for five years in an experiment in team building, disciplinary silo breaking, and co-educating social science, natural science, and journalism graduate students in carbon cycle dynamics, economics and policy.
Past Courses
- ENVS 1000: Introduction to Environmental Studies
- ENVS 3930: Internship in Environmental Studies
- ENVS 4990: Senior Thesis in Environmental Studies
- ENVS 5900: Carbon, Climate, and Society
- ENVS/GEOL 3520: Environmental Issues in Geosciences
- GEOL 1070: Global Change
- GEOL 1110: Global Change Lab
- GEOL 5700: Environmental Isotopes
- GEOL 5700: Current Literature in Global Change Research
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Outreach
Videos about climate change
- Abrupt Impacts of Climate Change: Anticipating surprises
- 120 Seconds of Science with Doc Ryan
- Climate Change Impacts are Happening Faster and Faster