Deducing Multidecadal Anthropogenic Global Warming Trends Using Multiple Regression Analysis

Jiansong Zhou Department of Applied Mathematics, University of Washington, Seattle, Washington

Search for other papers by Jiansong Zhou in
Current site
Google Scholar
PubMed
Close
and
Ka-Kit Tung Department of Applied Mathematics, University of Washington, Seattle, Washington

Search for other papers by Ka-Kit Tung in
Current site
Google Scholar
PubMed
Close
Restricted access

Abstract

To unmask the anthropogenic global warming trend imbedded in the climate data, multiple linear regression analysis is often employed to filter out short-term fluctuations caused by El Niño–Southern Oscillation (ENSO), volcano aerosols, and solar forcing. These fluctuations are unimportant as far as their impact on the deduced multidecadal anthropogenic trends is concerned: ENSO and volcano aerosols have very little multidecadal trend. Solar variations do have a secular trend, but it is very small and uncertain. What is important, but is left out of all multiple regression analysis of global warming so far, is a long-period oscillation called the Atlantic multidecadal oscillation (AMO). When the AMO index is included as a regressor (i.e., explanatory variable), the deduced multidecadal anthropogenic global warming trend is so impacted that previously deduced anthropogenic warming rates need to be substantially revised. The deduced net anthropogenic global warming trend has been remarkably steady and statistically significant for the past 100 yr.

Corresponding author address: Ka-Kit Tung, Department of Applied Mathematics, University of Washington, Box 352420, Seattle, WA 98195-2420. E-mail: tung@amath.washington.edu

Abstract

To unmask the anthropogenic global warming trend imbedded in the climate data, multiple linear regression analysis is often employed to filter out short-term fluctuations caused by El Niño–Southern Oscillation (ENSO), volcano aerosols, and solar forcing. These fluctuations are unimportant as far as their impact on the deduced multidecadal anthropogenic trends is concerned: ENSO and volcano aerosols have very little multidecadal trend. Solar variations do have a secular trend, but it is very small and uncertain. What is important, but is left out of all multiple regression analysis of global warming so far, is a long-period oscillation called the Atlantic multidecadal oscillation (AMO). When the AMO index is included as a regressor (i.e., explanatory variable), the deduced multidecadal anthropogenic global warming trend is so impacted that previously deduced anthropogenic warming rates need to be substantially revised. The deduced net anthropogenic global warming trend has been remarkably steady and statistically significant for the past 100 yr.

Corresponding author address: Ka-Kit Tung, Department of Applied Mathematics, University of Washington, Box 352420, Seattle, WA 98195-2420. E-mail: tung@amath.washington.edu
Save
  • Benestad, R. E., and G. A. Schmidt, 2009: Solar trends and global warming. J. Geophys. Res., 114, D14101, doi:10.1029/2008JD011639.

  • Booth, B. B. B., N. J. Dunstone, P. R. Halloran, T. Andrews, and N. Bellouin, 2012: Aerosols implicated as a prime driver of twentieth-century North Atlantic climate variability. Nature, 484, 228232.

    • Search Google Scholar
    • Export Citation
  • DelSol, T., M. K. Tippett, and J. Shukla, 2011: A significant component of unforced multidecadal variability in the recent acceleration of global warming. J. Climate, 24, 909026.

    • Search Google Scholar
    • Export Citation
  • Delworth, T. L., and M. E. Mann, 2000: Observed and simulated multidecadal variability in the Northern Hemisphere. Climate Dyn., 16, 661676.

    • Search Google Scholar
    • Export Citation
  • Delworth, T. L., and T. R. Knutson, 2000: Simulation of early 20th century global warming. Science, 287, 22462250.

  • Dima, M., and G. Lohmann, 2007: A hemispheric mechanism for the Atlantic multidecadal oscillation. J. Climate, 20, 27062719.

  • Enfield, D. B., A. M. Mestas-Nuñez, and P. J. Trimble, 2001: The Atlantic multidecadal oscillation and its relation to rainfall and river flows in the continental U.S. Geophys. Res. Lett., 28, 20772080.

    • Search Google Scholar
    • Export Citation
  • Folland, C. K., D. E. Parker, and F. E. Kates, 1984: Worldwide marine temperature fluctuations 1856–1981. Nature, 310, 670673.

  • Foster, G., and S. Rahmstorf, 2011: Global temperature evolution 1979-2010. Environ. Res. Lett., 6, 18.

  • Hansen, J. A., and Coauthors, 2007: Climate simulations for 1880-2003 with GISS modelE. Climate Dyn., 29, 661696.

  • Huang, N. E., and Coauthors, 1998: The empirical mode decomposition and the Hilbert spectrum for nonlinear and non-stationary time series analysis. Proc. Roy. Soc. London,454A, 903995.

    • Search Google Scholar
    • Export Citation
  • Knight, J. R., R. J. Allan, C. K. Folland, M. Vellinga, and J. E. Mann, 2005: A signature of persistent natural thermohaline circulation cycles in observed climate. Geophys. Res. Lett., 32,L20708, doi:10.1029/2005GL024233.

    • Search Google Scholar
    • Export Citation
  • Kopp, G. and J. L. Lean, 2011: A new, lower value of total solar irradiance: Evidence and climate significance. Geophys. Res. Lett.,38, L01706, doi:10.1029/2010GL045777.

  • Lean, J. L., and D. H. Rind, 2008: How natural and anthropogenic influences alter global and regional surface temperatures: 1889 to 2006. Geophys. Res. Lett., 35, L18701, doi:10.1029/2008GL034864.

    • Search Google Scholar
    • Export Citation
  • Meehl, G. A., C. Covey, T. Delworth, M. Latif, B. McAvaney, J. F. B. Mitchell, R. J. Stouffer, and K. E. Taylor, 2007: The WCRP CMIP3 multimodel dataset: A new era in climate change research. Bull. Amer. Meteor. Soc., 88, 13831394.

    • Search Google Scholar
    • Export Citation
  • Morce, C. P., J. J. Kennedy, N. A. Rayner, and P. D. Jones, 2012: Quantifying uncertainties in global and regional temperature change using an ensemble of observational estimates: The HadCRUT4 data set. J. Geophys. Res., 117, D08101, doi:10.1029/2011JD017187.

    • Search Google Scholar
    • Export Citation
  • Sato, K., J. E. Hansen, M. P. McCormick, and J. B. Pollack, 1993: Stratospheric aerosol optical depths, 1850–1990. J. Geophys. Res., 98 (D12), 22 98722 994.

    • Search Google Scholar
    • Export Citation
  • Schlesinger, M. E., and N. Ramankutty, 1994: An oscillation in the global climate system of period 65-70 years. Nature, 367, 723726.

  • Semenov, V. A., M. Latif, D. Dommenget, N. Keenlyside, A. Strehz, T. Martin, and W. Park, 2010: The impact of North Atlantic–Arctic multidecadal variability on Northern Hemisphere surface air temperature. J. Climate, 23, 56685677.

    • Search Google Scholar
    • Export Citation
  • Solomon, S., D. Qin, M. Marquis, K. Averyt, M. M. B. Tignor, H. L. Miller Jr., and Z. Chen, Eds., 2007: Climate Change 2007: The Physical Science Basis. Cambridge University Press, 996 pp.

  • Thompson, D. W. J., J. J. Kennedy, J. M. Wallace, and P. D. Jones, 2008: A large discontinuity in the mid-twentieth century in observed global-mean surface temperature. Nature, 453, 646–649, doi:10.1038/nature06982.

    • Search Google Scholar
    • Export Citation
  • Tung, K. K., J. Zhou, and C. D. Camp, 2008: Constraining model transient climate response using independent observations of solar-cycle forcing and response. Geophys. Res. Lett., 35, L17707, doi:10.1029/2008GL034240.

    • Search Google Scholar
    • Export Citation
  • Wang, Y.-M., J. Lean, and N. R. Sheeley Jr., 2005: Modeling the sun's magnetic field and irradiance since 1713. Astrophys. J., 625, 522538.

    • Search Google Scholar
    • Export Citation
  • Wei, W. W., and G. Lohmann, 2012: Simulated Atlantic multidecadal oscillation during the Holocene. J. Climate, 25, 6989–7002.

  • Woodward, W. A., and H. L. Gray, 1995: Selecting a model for detecting the presence of a trend. J. Climate, 8, 19291937.

  • Wu, Z., and N. E. Huang, 2009: Ensemble empirical mode decomposition: A noise-assisted data analysis method. Adv. Adapt. Data Anal., 1, 114.

    • Search Google Scholar
    • Export Citation
  • Wu, Z., N. E. Huang, J. M. Wallace, B. V. Smoliak, and X. Chen, 2011: On the time-varying trend in global-mean surface temperature. Climate Dyn., 37, 759–773, doi:10.1007/s00382-011-1128-8.

    • Search Google Scholar
    • Export Citation
  • Zhang, R., and Coauthors, 2013: Have aerosols caused the observed Atlantic multidecadal variability? J. Atmos. Sci., in press.

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 3077 892 54
PDF Downloads 1856 442 23