Global atmospheric measurements of CO2, CH4, CO, H2, N2O, SF6, and isotopic ratios in several of those species. Numerical models of atmospheric transport. Field measurements of air-sea gas exchange.
Pieter Tans has been actively interested in mankind's influence on climate since he was a student. Convinced that man-made climate change was a problem certain to grow in importance over time, he changed direction from solid state physics to Earth sciences. His PhD study used carbon-14 and carbon-13 in tree rings to reconstruct the increase of atmospheric carbon dioxide since the late 19th century. As part of this work he developed a new way to calculate the behavior of CO2 isotopic ratios, separating the influence of net exchange of total carbon between Earth reservoirs from pure isotopic exchange in which 12CO2 and 13CO2 molecules are exchanged between air and water, for example, without changing total carbon in either reservoir. This formalism to deal with isotopic exchange is now universally followed in the field.
Pieter led the National Oceanic and Atmospheric Administration (NOAA) Carbon Cycle Greenhouse Gases group from 1985 until 2019. He discovered the existence of a very large sink (uptake) of CO2 by terrestrial ecosystems at mid-latitudes in the northern hemisphere, partially offsetting the emissions caused by the burning of coal, oil, and natural gas. Over four decades the carbon cycle group has maintained what we now call NOAA’s Global Greenhouse Gas Reference Network (GGGRN), producing the most widely used data of atmospheric CO2, CH4, and several other greenhouse gases.
Since 1991, and still ongoing, we have had a very close collaboration between the NOAA GGGRN and INSTAAR's Stable Isotope Laboratory. This resulted in global measurements of 13C/12C and 18O/16O ratios in CO2 and 13C/12C and D/H ratios in CH4, which can unravel the contribution of different source types to the observed trends. In 2004 a similar cooperation started between GGGRN and INSTAAAR's AMS Radiocarbon Preparation & Research Lab for measurements of the 14C/total C ratio in atmospheric CO2, which uniquely separates the recent emissions of fossil fuel CO2 from other sources.
GGGRN is also active in the development of CarbonTracker, a global measurement and modeling system developed to keep track of sources (emissions to the atmosphere) and sinks (removal from the atmosphere) of carbon dioxide around the world. A version of CarbonTracker for methane (CH4) has also been developed, as well as CarbonTracker-Lagrange (CT-L), a regional inverse modeling framework designed for estimating North American greenhouse gas emissions and uptake fluxes.
Inspired by the observation that 90 year old air was present near the bottom of the firn layer at South Pole, despite being in contact with today’s atmosphere, Pieter invented the AirCore in 2002. It is a 100-150 m long coiled tube hoisted by balloon to 30 km altitude. One side is open, the other end is closed. It is initially filled with a known reference gas that streams out from the open end during ascent to lower pressures. During the subsequent descent by parachute, atmospheric air streams back in, providing a continuous sample from 30 km to the surface.
Education
- PhD: University of Groningen, 1978
Awards
- Fellow, American Association for the Advancement of Science (AAAS), 2011
- Roger Revelle Medal, American Geophysical Union, 2010
- Fellow, American Geophysical Union (AGU), 2004
- Corresponding Member, Royal Netherlands Academy of Arts and Sciences, 1995
Public engagement
- Humans are messing with Earth's thermostat: We must solve climate change. Opinion by Barbara G. Schneider, Mike Nelson and Pieter Tans, The Tennessean, July 11, 2022.
- The World's Littlest Book on Climate: Ten facts in ten minutes about CO2, by Mike Nelson, Pieter Tans, and Michael Banks, available free online.
- Pieter's profile on 97 Hours of Consensus, Sceptical Science.
- Video interviews of Pieter Tans on the pace of climate change, sea level rise, the unsettling implications of climate change, and making the abstract concrete via the Science History Institute.
Selected publications
Basu, S., Lan, X., Dlugokencky, E., Michel, S., Schwietzke, S., Miller, J. B., Bruhwiler, L., Oh, Y., Tans, P. P., Apadula, F., Gatti, L. V., Jordan, A., Necki, J., Sasakawa, M., Morimoto, S., Di Iorio, T., Lee, H., Arduini, J., Manca, G., 2022: Estimating emissions of methane consistent with atmospheric measurements of methane and δ13C of methane. Atmospheric Chemistry and Physics, 22(23): 15351-15377. doi 10.5194/acp-22-15351-2022
Tans, P., 2022: Fill dynamics and sample mixing in the AirCore. Atmospheric Measuring Techniques, 15(6):1903-1916. doi 10.5194/amt-15-1903-2022
Tans, P., 2022: Reminiscing on the use and abuse of 14C and 13C in atmospheric CO2. Radiocarbon 64(4): 747-760. doi 10.1017/RDC.2022.7
Lan, X., Basu, S., Schwietzke, S., Bruhwiler, L., Dlugokencky, E., Michel, S., Sherwood, O., Tans, P., Thoning, K., Etiope, G., Zhyuang, Q., Liu, L., Miller, J., Petron, G., Vaughn, B., Crippa, M., 2021: Improved constraints on global methane emissions and sinks using δ13C-CH4. Global Biogeochemical Cycles 35(6): e2021GB007000. doi 10.1029/2021GB007000
Basu, S., Lehman, S. J., Miller, J. B., Andrews, A. E., Sweeney, C., Gurney, K. R., Southon, J., Tans, P., 2020: Estimating US fossil fuel CO2 emissions from measurements of 14C in atmospheric CO2. Proceedings of the National Academy of Sciences, 117(24): 13300-13307. doi 10.1073/pnas.1919032117
Hu, L., Andrews, A. E., Thoning, K. W., Sweeney, C., Miller, J. B., Michalak, A., Dlugokencky, E., Tans, P., Shiga, Y., Mountain, M., Nehrkorn, T., Montzka, S., McKain, K., Kofler, J., Trudeau, M., Michel, S., Biraud, S., Fisher, M. L., Worthy, D., Vaughn, B., White, J., Yadav, V., Basu, S., van der Velde, I., 2019: Enhanced North American carbon uptake associated with El Niño, Science Advances, 5(6): eaaw0076. doi 10.1126/sciadv.aaw0076
Van der Velde, I., Miller, J. B., van der Molen, M., Tans, P., Vaughn, B., White, J. W. C., Schaefer, K., Peters, W., 2018: The CarbonTracker data assimilation system for CO2 and δ13C (CTDAS-C13 v1.0): Retrieving information on land-atmosphere exchange processes. Geoscientific Model Development, 11(1): 283-304. doi 10.5194/gmd-11-283-2018
Tans, P., Crotwell, A., Thoning, K., 2017: Abundances of isotopologues and calibration of CO2 greenhouse gas measurements. Atmospheric Measurement Techniques, 10(7): 2669-2685. doi 10.5194/amt-10-2669-2017
Schwietzke, S., Sherwood, O., Bruhwiler, L., Miller, J. B., Etiope, G., Dlugokencky, E., Michel, S. E., Arling, A., Vaughn, B., White, J. W. C., Tans, P., 2016: Upward revision of global fossil fuel methane emissions based on isotopic data. Nature, 538, 88-91. doi 10.1038/nature19797
Masarie, K. A., Peters, W., Jacobson, A., Tans, P. P., 2014: ObsPack: A framework for the preparation, delivery, and attribution of atmospheric greenhouse gas measurements. Earth Systems Science Data 6(2): 375-384. doi 10.5194/essd-6-375-2014
Lehman, S., Miller, J. B., Wolak, C., Southon, J., Tans, P. P., Montzka, S. A., Sweeney, C., Andrews, A., LaFranchi, B., Guilderson, T. P., Turnbull, J. C., 2013: Allocation of terrestrial carbon sources using 14CO2: Methods, measurements and modeling. Radiocarbon, 55(3): 1484-1495. doi 10.1017/S0033822200048414
Ballantyne, A. P., Alden, C. B., Miller, J. B., Tans, P. P., White, J. W. C., 2012: Increase in observed net carbon dioxide uptake by land and oceans during the last 50 years. Nature, 488: 70-72. doi 10.1038/nature11299
Turnbull, J. C., Karion, A., Fisher, M. L., Falloona, I., Guilderson, T., Lehman, S. J., Miller, B. R., Miller, J. B., Montzka, S., Sherwood, T., Saripalli, S., Sweeney, C., Tans, P. P., 2011: Assessment of fossil fuel carbon dioxide and other anthropogenic trace gas emissions over Sacramento, California in spring 2009. Atmospheric Chemistry and Physics, 11(2): 705-721. doi 10.5194/acp-11-705-2011
Karion, A., Sweeney, C., Tans, P., Newberger, T., 2010: AirCore: An innovative atmospheric sampling system. Journal of Atmospheric and Oceanic Technology, 27(11): 1839-1853. doi 10.1175/2010JTECHA1448.1
Wouter, P., Jacobson, A. R., Sweeney, C., Andrews, A. E., Conway, T. J., Masarie, K., Miller, J. B., Bruhwiler, L. M. P., Petrón, G., Hirsch, A. I., Worthy, D. E. J., van der Werf, G. R., Randerson, J. T., Wennberg, P. O., Krol, M. C., Tans, P. P., 2007: An atmospheric perspective on North American carbon dioxide exchange: CarbonTracker. Proceedings of the National Academy of Sciences, 104(48): 18925-18930. doi 10.1073/pnas.0708986104
Turnbull, J. C., Lehman, S. J., Miller, J. B., Sparks, R. J., Southon, J. R., Tans, P. P., 2007: A new high precision 14CO2 time series for North American continental air. Journal of Geophysical Research, 112(D11): D11310. doi: 10.1029/2006JD008184
Hofmann, D., Butler, J. H., Dlugokencky, E. J., Elkins, J. W., Masarie, K., Montzka, S. A., Tans, P., 2006: The role of carbon dioxide in climate forcing from 1979-2004: Introduction of the Annual Greenhouse Gas Index. Tellus B, 58(5): 614-619. doi 10.1111/j.1600-0889.2006.00201.x
Turnbull, J. C., Miller, J. B., Lehman, S. J., Tans, P. P., Sparks, R. J., Southon, J., 2006: Comparison of 14CO2, CO, and SF6 as tracers for recently added fossil fuel CO2 in the atmosphere and implications for biological CO2 exchange. Geophysical Research Letters, 33(1): L01817. doi 10.1029/2005GL024213
Miller, J. B., Tans, P. P., White, J. W. C., Conway, T. J., Vaughn, B. W., 2003: The atmospheric signal of terrestrial carbon isotopic discrimination and its implication for partitioning carbon fluxes. Tellus B, 55(2): 197-206. doi 10.3402/tellusb.v55i2.16696
Miller, J. B., Mack, K. A., Dissly, R., White, J. W. C., Dlugokencky, E. J., Tans, P. P., 2002: Development of analytical methods and measurements of 13C/12C in atmospheric CH4 from the NOAA/CMDL Global Air Sampling Network. Journal of Geophysical Research—Atmospheres, 107(D13). doi 10.1029/2001JD000630
Masarie, K. A., Langenfelds, R. L., Allison, C. E., Conway, T. J., Dlugokencky, E. J., Francey, R. J., Novelli, P. C., Steele, L. P., Tans, P. P., Vaughn, B., White, J. W. C., 2001: NOAA/CSIRO flask air intercomparison experiment: A strategy for directly assessing consistency among atmospheric measurements made by independent laboratories. Journal of Geophysical Research—Atmospheres, 106(D17): 20445-20464. doi 10.1029/2000JD000023
Battle, M., Bender, M. L., Tans, P. P., White, J. W. C., Ellis, J. T., Conway, T., Francey, R. J., 2000: Global carbon sinks and their variability inferred from atmospheric O2 and δ13C. Science, 287(5462): 2467-2470. doi 10.1126/science.287.5462.2467
Peylin, P., Ciais, P., Denning, A. S., Tans, P. P., Berry, J. A., White, J. W. C., 1999: A 3-dimensional study of δ18O in atmospheric CO2: Contribution of different land ecosystems. Tellus B, 51(3): 642-667. doi 10.3402/tellusb.v51i3.16452
Miller, J. B., Yakir, D., White, J. W. C., Tans, P. P., 1999: Measurement of 18O/16O in the soil-atmosphere CO2 flux. Global Biogeochemical Cycles, 13(3): 761-774. doi 10.1029/1999GB900028
Tans, P. P., 1998: Oxygen isotopic equilibrium between carbon dioxide and water in soils. Tellus B, 50(2): 163-178. doi 10.3402/tellusb.v50i2.16094
Zhao, C., Tans, P. P., Thoning, K. W., 1997: A high precision manometric system for absolute calibrations of CO2 in dry air. Journal of Geophysical Research—Atmospheres, 102(D5): 5885-5894. doi 10.1029/96JD03764
Bender, M., Ellis, T., Tans, P., Francey, R., Lowe, D., 1996: Variability in the O2/N2 ratio of southern hemisphere air, 1991-1994: Implications for the carbon cycle. Global Biogeochemical Cycles, 10(1): 9-21. doi 10.1029/95GB03295
Ciais, P., Tans, P. P., Trolier, M., White, J. W. C., Francey R. J., 1995: A large northern hemisphere terrestrial CO2 sink indicated by the 13C/12C ratio of atmospheric CO2. Science, 269(5227): 1098-1102.
Francey, R. J., Tans, P. P., Allison, C. E., Enting, I. G., White, J. W. C., Trolier, M., 1995: Changes in oceanic and terrestrial carbon uptake since 1982. Nature, 373: 326-330. doi 10.1038/373326a0
Masarie, K. A., Tans, P. P., 1995: Extension and integration of atmospheric carbon dioxide data into a globally consistent measurement record. Journal of Geophysical Research—Atmospheres, 100(D6): 11593-11610. doi 10.1029/95JD00859
Ciais, P., Tans, P. P., White, J. W. C., Trolier, M., Francey, R. J., Berry, J. A., Randall, D. R., Sellers, P. J., Collatz, J. G., Schimel, D. S., 1995: Partitioning of ocean and land uptake of CO2 as inferred by δ13C measurements from the NOAA/CMDL global air sampling network. Journal of Geophysical Research—Atmospheres, 100(D3): 5051-5070. doi 10.1029/94JD02847
Dlugokencky, E. J., Masarie, K. A., Lang, P. M., Tans, P. P., Steele, L. P., Nisbet, E. G., 1994: A dramatic decrease in the growth rate of atmospheric methane in the northern hemisphere during 1992. Geophysical Research Letters, 21(1): 45-48. doi 10.1029/93GL03070
Tans, P. P., Berry, J. A., Keeling, R. F., 1993: Oceanic 13C/12C observations: A new window on ocean CO2 uptake. Global Biogeochemical Cycles, 7(2): 353-368. doi 10.1029/93GB00053
Tans, P. P., Fung, I. Y., Takahashi T., 1990: Observational constraints on the global atmospheric CO2 budget. Science, 247(4949): 1431-1438. doi 10.1126/science.247.4949.1431
Thoning, K. W., Tans, P. P., Komhyr, W. D., 1989: Atmospheric carbon dioxide at Mauna Loa Observatory: 2. Analysis of the NOAA GMCC data, 1974-1985. Journal of Geophysical Research—Atmospheres, 94(D6): 8549-8565. doi 10.1029/JD094iD06p08549
Tans, P. P., Conway, T. J., Nakazawa, T., 1989: Latitudinal distribution of the sources and sinks of atmospheric carbon dioxide derived from surface observations and an atmospheric transport model. Journal of Geophysical Research—Atmospheres, 94(D4): 5151-5172. doi 10.1029/JD094iD04p05151
Francey, R. J., Tans, P. P., 1987: Latitudinal variation in oxygen-18 of atmospheric CO2. Nature, 327: 495-497. doi 10.1038/327495a0
Tans, P. P., Mook, W. G., 1980: Past atmospheric CO2 levels and the 13C/12C ratios in tree rings. Tellus, 32(3): 268-283. doi 10.3402/tellusa.v32i3.10582
Tans, P. P., Mook, W. G., 1979: Design, construction and calibration of a high accuracy carbon-14 counting set up. Radiocarbon, 21(1): 22-40. doi 10.1017/S0033822200004197
Keeling, C. D., Mook, W. G., Tans, P. P., 1979: Recent trends in the 13C/12C ratio of atmospheric carbon dioxide. Nature, 277: 121-123. doi 10.1038/277121a0
