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Natural atmospheric 14C variation and the Suess effect


THE dilution of the atmospheric 14CO2 concentration by large amounts of fossil-fuel derived CO2 which do not contain any 14C is commonly called the Suess effect. Its magnitude can be calculated with the same geochemical models as the global carbon cycle that also predict the future rise of atmospheric CO2 to be caused by the combustion of fossil fuels. Validation of a CO2 predictive model with the Suess effect 14C data is important because these two phenomena have a common cause, and therefore register model responses at roughly the same frequencies. Measurements of the Suess effect yield values between −15‰, and −25‰ in Δ 14C (in 1950)1, while different model predictions also cover about this range2,3. The requirement that a model correctly reproduces the Suess effect becomes a strong constraint when the accuracy of the measurement is improved to better than 2‰. 14C measurements in tree rings to an accuracy of 1.2‰ are reported here. The results indicate that the natural fluctuations of atmospheric 14C as yet preclude determination of the Suess effect to the accuracy required by the models.

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  1. Lerman, J. C., Mook, W. G. & Vogel, J. C. in Radiocarbon variations and absolute chronology (ed. Olsson, I. U.) 275–301 (Wiley, New York, 1970).

    Google Scholar 

  2. Bacastow, R. & Keeling, C. D. in Carbon and the biosphere (eds Woodwell, G. M. & Pecan, E. V.) 86–135 (US Atomic Energy Commission Conference 720510, 1973).

    Google Scholar 

  3. Oeschger, H., Siegenthaler, U., Schotterer, U. & Gugelmann, A. Tellus 27, 168–192 (1975).

    Article  ADS  CAS  Google Scholar 

  4. Tans, P. P. & Mook, W. G. Radiocarbon 21, 22–40 (1978).

    Article  Google Scholar 

  5. Tans, P. P., de Jong, A. F. M. & Mook, W. G. Nature 271, 234–235 (1978).

    Article  ADS  CAS  Google Scholar 

  6. Damon, P. E., Long, A. & Wallick, E. I. Earth planet. Sci. Lett. 20, 300–306 (1973).

    Article  ADS  CAS  Google Scholar 

  7. Keeling, C. D. Tellus 25, 174–197 (1973).

    Article  ADS  CAS  Google Scholar 

  8. Lingenfelter, R. E. & Ramaty, R. in Radiocarbon variations and absolute chronology (ed. Olsson, I. U.) 513–537 (Wiley, New York, 1970).

    Google Scholar 

  9. Forbush, S. E. Phys. Rev. 70, 771 (1946).

    Article  ADS  CAS  Google Scholar 

  10. Forbush, S. E., Stinchomb, T. B. & Schein, M. Phys. Rev. 79, 501 (1950).

    Article  ADS  Google Scholar 

  11. Münnich, K. O. Naturwisschaften 50, 218–221 (1963).

    Article  ADS  Google Scholar 

  12. östlund, H. G. & Engstrand, L. G. Radiocarbon 5, 203–227 (1963).

    Article  Google Scholar 

  13. Nydal, R., Lövseth, K. & Gulliksen, S. in Proc. 9th int. Conf. Radiocarbon Dating, California (in the press).

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TANS, P., DE JONG, A. & MOOK, W. Natural atmospheric 14C variation and the Suess effect. Nature 280, 826–828 (1979).

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