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Is Global Warming for Real?

Is Global Warming for Real?. J. C. Sprott Department of Physics University of Wisconsin - Madison Presented at the Chaos and Complex Systems Seminar In Madison, Wisconsin On January 17, 2006. Some Evidence. From Recent Seminars. Greenland Ice-core Data (C. S. Clay). 782,000 years.

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Is Global Warming for Real?

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  1. Is Global Warming for Real? J. C. Sprott Department of Physics University of Wisconsin - Madison Presented at the Chaos and Complex Systems Seminar In Madison, Wisconsin On January 17, 2006

  2. Some Evidence

  3. From Recent Seminars Greenland Ice-core Data (C. S. Clay) 782,000 years Lake Mendota Ice Cover (John Magnuson) 150 years

  4. Prediction Methods • Extrapolation methods • Simple extrapolation • Moving average • Trends • Linear methods • Simple regression • Autoregression • All poles method • Nonlinear methods • Method of analogs • Artificial neural network

  5. Simple Extrapolation 3 2 1 Order = 0 Fit the last few points to a polynomial

  6. Moving Average Lags = 0 1 2 3 Average some number of previous points

  7. Trends 2 1 Lags = 0 Follow the trend of some number of previous points

  8. Linear Regression 2 3 Order = 0 1 Fit a polynomial to the entire data set

  9. Autoregression 4 2 Order = 0 xt = a0 + a1xt-1 + a2xt-2 + …

  10. All Poles Method Poles = 0 2 4 1 Assume a sum of poles in the complex plane

  11. Method of Analogs Lags = 0 2 1 Find the closest similar previous sequence

  12. Artificial Neural Network D aij N bi 6 neurons Lags = 3 tanh x x xt = xt-1 + Sbitanh[ai0 + ai1xt-1 + ai2xt-2 + ai3xt-3]

  13. Artificial Neural Network 6 neurons Lags = 3 xt = xt-1 + Sbitanh[ai0 + ai1xt-1 + ai2xt-2 + ai3xt-3]

  14. Artificial Neural Network 6 neurons Lags = 4 xt = xt-1 + Sbitanh[ai0 + ai1xt-1 + … + ai4xt-4]

  15. Artificial Neural Network 6 neurons Lags = 9 This year: 26 days xt = xt-1 + Sbitanh[ai0 + ai1xt-1 + … + ai9xt-9]

  16. Artificial Neural Network 6 neurons Lags = 9 Chaotic? 450-year prediction ~30-70 days frozen xt = xt-1 + Sbitanh[ai0 + ai1xt-1 + … + ai9xt-9]

  17. Conclusion • Eight predictors with ten or more values for the parameter give 80 very different predictions • We could take an average of all the predictions • Better yet, take the median of the predictions (half higher, half lower)

  18. Median of 80 Predictions Prediction for this season: 91 days (March 19th thaw)

  19. Ice Core DataNeural Network Predictor 6 neurons Lags = 9 782,000 years xt = xt-1 + Sbitanh[ai0 + ai1xt-1 + … + ai9xt-9]

  20. Ice Core DataAverage of 80 Predictions 782,000 years

  21. Closing Thoughts • The Earth is getting warmer • Human activity may not be the main cause • Global warming may not be a bad thing • Technological solutions may be available and relatively simple

  22. http://sprott.physics.wisc.edu/ lectures/warming.ppt (this talk) sprott@physics.wisc.edu (contact me) References

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